Techmoan channel - Content is good. Reviews are good. Pronunciation is good. Terminology is good. Enjoyment factor, at this end, is good. So, all in all, all good. Thanks for all your hard work Mat. It is much appreciated.
Hi, electrical engineer here. Gold Xuan Zu: the circuitboard is a combination of through-hole components (soldered THROUGH the circuit board, mainly on the right) and SMD components (Surface Mount Device soldered ON the circuit board mainly on the left) which is why they don't seem connected if you look on the back. It uses HQ surface-mount capacitors which filters the high/low pass frequencies and along with the tubes/valves (which act like old-school transistors) creates the analog vibe. The two IC's at the front are (digital) dual amplifiers and actually seem high grade. Generally the circuit is of very high quality and an amazing finish for a budget tube/valve amp. So no suprise on actually being better. Zhilai: "A worthless heap of shit" as my favorite Aussie EEV-blogger likes to call them. All of the capacitors are of terrible quality and one of them is already busted (the electrolytic caps as we call them have fluids inside that swell up after time). Not worth explaining the rest. Garbage. Little Bear: What. The. Actual. F*ck? Almost ALL of the components are obsolete/refurbished, it's a wacky mix of horizontal and vertical circuitboards probably to cram all that circuitry inside. All I see is trouble. Not much to add.
Agree with all of gigglygigglydude's comments and would like to mention that a better set of tubes will probably get rid of the microphonics in the Gold Xuan Zu amp as this is a mechanical issue with the internal components of the tube.
might be wrong but it looks like they might be using a switching boost converter to jack up the voltage to run the heaters and just filtering out the noise post amplification, at least on the first two. Don't know much about tubes, but i'm not sure what else that other little smd chip could be doing. agree with giggly, xuanzo looks descent others are junk
Well, there is nothing "digital" on the Op-Amps, as it is analogue in and analogue out. Per definition, as tubes are of course analogue. First amp looks the cleanest build. Little bear components obsolete/refurbished: no, it is just the standard Chinese junk. Nothing valuable enough to salvage / refurbish. Wacky mix: I guess you never saw electronics in confined spaces before? Signed, a real electronics engineer.
gigglygigglydude Thanks so much - really appreciate the knowledge. Went and bought the amp you recommended cos I want to do my toe in the water without spending a ton. Please keep helping people with posts like this.
The most well-equipped high end home electronics store in my city is easily one of the least welcoming places I've ever been to. Watching that "HiFi Shop" sketch definitely reminded me of being condescended to by old dudes who were very proud of their vast knowledge that they were blessed with at birth. I appreciate your sincerity and your enthusiasm for plain speaking. Carry on, Mat!
10:49 "Ya sorry about the breathing there, it's something that I do from time to time. I've been trying to stop, but it just seems to keep happening." Very good sir, and watching this now in 2019, you were saying tubes fine as far as I am concerned. We all have accents and if literally everyone knows what you are saying, they are just being rude. Anyways thanks for the content.
***********TEARDOWN TEARDOWN TEARDOWN TEARDOWN********* There is a choice to make... You can either be A) The 50th person who links to the eevblog teardown video B) Someone who reads comments & click here th-cam.com/video/coSt5HWRvv4/w-d-xo.html
+Techmoan my only concern was the price of the units as i have a ok valve amp but the valves cost around £10 each So i couldn't see how the ones you tested were going to be much good.
+Techmoan EEVblog (David Jones) in Australia did a TH-cam technical tear-down of the gold valve amp, shown at 11:38. The valves in it are hard wired as cathode follower triodes. Thus, they have no voltage gain, but will operate on voltages as low as 12.
+TheBaconWizard Dave Jones (EEVBlog) drew a circuit diagram of that amp, which showed that the valves (tubes) did not provide any amplification. Even the buffering they provided served no purpose, and it was clear that the valves could be bridged out of the circuit. Bridging the valves out would undoubtedly reduce the distortion. Not worth the cost.
A blast from the past. But I thought the cassette was the most intriguing thing I saw. A good thorough layman's review (and easy video to watch too). Some times you find out they're duds. That's the point.
Also, these are multi layer circuit boards. The tracks on the bottom are only parts of the traces going to the tubes. Look carefully art the top view. There may also be traces in between layers.
A few short comments (I don't like typing a lot): In the late '60s I watched my father and uncle build hi-fi and electronics kits (Knight, Scott, Dynaco etc.) From early to late '70s I built Heathkits and Eico, and worked in TV repair shops. I got to the point where I can look inside a tube and identify which leads go to the anode, grid(s), cathode, heater etc. Came in handy when the ID was rubbed off. Never worried about leaving fingerprints on the 1000s of tubes I handled. In fact skin oils on the higher power tubes only made a distinctive odor. Looking in my 1973 RCA Receiving Tube Manual I see that the 6J9 is a high mu triple triode. Doesn't list the others mentioned. To those who like the sound of tubes I say "have at it", the added distortion is like the fungus in a good cheese.
The 6021 subminiature tube is a twin triode. It looks like it was high quality as it was one of those subminiature tubes that were built to US Military specs back then. It was used for RF Amplification and Oscillation.
And therefore at this moment I shall declare this comment by +Johan Ouweneel as the best reply for all those who paid their attention to the unrelevant on the previous video on this topic.
I'm no engineer (yet) but from what i know and can see a) all of them send the audio through the tubes, but are not necessary using them for amplification (microphonics are a clear sign the audio is going through, but the tubes could just be configured for a gain of one), b) all of them have ne5532 dual op amps, that probaply do the actual amplification. On the gold one it seems to be pretty obviously using one on the input and one on the output, so probaply in->opamp->tubes->opamp->out, the tubes probaply have no or almost no gain, just to colour the sound. COuld be that they actually do the gain an the output opamps are just used as buffers. There are coils and some smd chips on there, together with a bunch of caps, so that's probaply a power supply section, but as the caps are all 16 or 10V ratet it's not gonna be a step up converter, my guess would be switching step down to power heaters, so they don't generate to much heat as they would with regular linear regulators. The silver one has only one ne5532, so only one solid state stage, the smd device at the rear is probaply a buffer for the line in. There is angain an inductor with that to220 package device stuck on the back, so again probaply voltage drop, but this time probaply just a 78xx linear regulator and the coil for filtering something, but only one this time, wich makes sense because only one tube... wich makes me wonder, why the golden would use 2 separate power supplys for the heaters, normaly you would just put them in series and power them with a higher voltage (generally 6V or so per tube on those, so 12V, wich I would guess is also the input voltage), so maybe the re is just some power filtering on the golden one, who knows... The little bear looks really bodged together from modules, obvously the battery indicator on the rear panel, battery charger/protection on the thin part and the green module actually looks like a voltage converter, but it seems to be a step down converter from what I found, probaply again to run the heater more efficiently. Again only one ne5532 but some damn huge capaciators, much more like in a decent, powerful audio device, so either the circuit pulls a lot of current spikes or the battery converter generates a lot of noise. Also, two of those caps seem to be nichicon, wich is one of the top brands and I would not expect those in a device as ceap and shoddy as this, so could be fake.. then again, it looks like something built by some single dude in his basement, so maybe he got genuin ones because he knew they were better... probaply not though. About running the tubes with low voltage, while all of these are ment to be driven with 100s of volts, a lot of those small ones can operate on low voltages, even 10 and lower, but the possible output power drops significantly as well as amplification headroom, as there will be much more distortion (called operating in starved plate modey sometimes used as an effect for guitar sounds), but as a weak preamp/unity gain stage it should work That's what came to my mind, hope im not talking bullshit
Correct, they are not doing any amplifications, thats all left up to the op-amps(NE5532), the signal is passed through however. Even if they were used at low voltages, they would be firmly on the lower part of the gain curve where they are very unlinear.
i just want to say as a 22 y/o who is slowly getting into the HiFi scene (especially headphones), I really enjoy your videos and i find them very entertaining! I'm on a binge of watching at least 10 of your videos a day for a few days now and i have no intention of stopping. I love how in depth you go into the small things that are good and bad about each product. Also i love how you handle the haters lol. Keep making great content Matt, most of us really enjoy your time. God Bless
I've been watching your videos for a while they are great and informative as your opinion is based on what you have in front of you. I've personally been more involved in my HiFi passion in the past years with a complete CD / Turntable setup in the living room and a vintage cassette player in the kitchen. As I was doing researches about audio equipment when I first got into HiFi, reading online and going to audio stores, I got sucked in the HiFi world / community where everybody knows best. I can't stress this enough, most people who are into HiFi are taking it way too seriously and are very opinionated. At some point, I realized most of all opinions you get from those fanatics are rubbish and I learned to appreciate the time and care people put on their setup instead of what type of brand or equipment they own. Lets face it, you dont need 20,000$ of audio equipment to appreciate music.
many people comment part way through a video, dont realise its been said later on, and dont bother editing their comment, that or they stop watching half way, who knows, many viewers are about 16 and have never heard of a valve or anything that isnt an ipod shaped object
@tone167 - Sometimes the upload warrants some backlash though. Not to mention the shear number of brain-dead morons that comment. ... But one has to be selective in one's response. On uploads such as this and mostly other electronic or technical/DIY uploads, good etiquette is appropriate. But when one comes across an upload that is spouting bullshit, then one straps on the Colts, dons the poncho and flat-brimmed hat, boots and spurs, stuffs a Virginian in the gob and walks out onto the dusy street, with a determined countenance.
Hey man, you can't get bent out of shape over youtube comments. you will never be able to please everyone. I think your videos are nice and a good mix of technical and plain english. Keep doing what you do, you do it well.
Excellent follow up to a great video. Although strictly speaking the guitar music at 8:21 should have been on a left-handed 12 string guitar, otherwise it sounds like rubbish and is a waste of money.
I'm just a southern boy in the US and found your videos very informative and your accent pleasing, piss on those who criticize on detail and being politically correct. Most of the comments I read just shows that some folks have no electrical/technical background but yet insist on commenting about something they know nothing about. Funny how kids these days can search the internet for anything and still learn nothing.
I'm have EE background myself and always enjoyed your presentation method. Learned a lot from your videos. Layman's terms or understandable words is best communication for general public. Just do what you're comfortable with. We subscribed due to that. I'd turn away if your presentation was too technical.
Hey Techmoan! I have a degree in electrical engineering and nuclear engineering, so I took a close look at all three of the devices you have here to see if I can help you out a bit. I specialized in control systems and power distribution, so this isn't *quite* my area of expertise, but I'll see if I can take a crack at this. The IC chips that you see on the boards are NE5532 Op-Amps. It seems as if the IC's are working as a pre-amp and the signal that they output is fed to the tubes to boost the signal. I believe you refer to this as a hybrid amp. The two-tube amp has a separate op-amp and tube for each audio channel while the single tube amp has a single, dual channel op-amp and a single, dual channel tube. The single tube is pretty much just a two-in-one solution. Either way, both amps provide stereo hybrid sound. The pocket amp does the same thing as the others as well, but has a micro-tube and some dodgy components, leading to the lesser quality sound. Hope this helps!
+Classical Rips Hello fellow engineer! Indeed, there are opamps are inside each amplifier. Probably for coupling _chube_ output impedance to lower *impedance* of headphones. Choobes do amplification, opamps do coupling here, just my guess. Anyway that means they are hybrid and not cool enough and basically an abomination for a true audiophile. No sign of poweramp (_post-amp_, really?) ICs though as they usually come with heatsink pad even for a small headphne amps. The second (blue one) has something with a heatsink on a bottom side, but probably that's a part of power circuit. PS. CHUBE-CHUBE-CHUBE-YOUCHOOBE. Hope you forgive me for a little irony, Mat ;)
I built my own tube amp with pencil tubes for the fun of it. Tubes are high impedance devices while headphones are relatively low impedance. The NE 5532s are being used as the outputs as they have a high impedance input but low impedance output. The only other way to get an output from a tube that could drive most headphones would be to use an audio transformer which adds weight, complexity, and low level distortion.
Whatever you do, don't change your presenting style Matt. Love the lost format stuff and hope you wont stop once your audio and video cabinets are full. I love the fact you try stuff out, its always interesting. I have no interest in dash cams, but I haven't missed an episode! :-) Compulsive viewing.
+Paul Grimsley ive got plenty more things to show. Two large parcels turned up this evening and hopefully if the contents work they'll be used in some HiFi videos next year.
+Techmoan Excellent, Thanks for the reply Matt. I hope you continue your logical stance on audio demonstrations too, maybe with a quadrophonic a setup review! As far as I know TH-cam can't output audio in quad....? :-). All the best.
Welcome to audiophile land. You'll hear from people admonishing you for not polishing your tubes, or how you muststoring them in a freezer when not in use. While I know the actual proper way to use tuvbes is to have pure clear quartz rock crystal the, each weiging 25 grams apiece (very critical) 120 degrees apart Exactly 25 mm from each tube. Otherwise, the sound doesn't reflect properly, and you'll get listening fatigue. And forget about it is you use anything but a Zinc carbon battery to power them. Lithium batteries introduce serious temporal distortion
OMG - You need to elevate your interconnect and power cables off of the desk at least 3 inches and at least 90% of the run aligned parallel with the equator.
First time to your channel and your feedback on the comments is exceptional and the amount of detail and effort gone into them is what most people need to do. It’s great because anyone who doesn’t have a chip on their shoulders or will actually watch the video in its entirety before making a comment should appreciate your effort in trying to share an interest and that’s it.
Electronics APPRENTICE/ENTHUSIAST here (I AM NOT A PROFESSIONAL), I will try my best and to keep it simple: In order to simulate a delay, you have the following options: 1. Microcontroller or microprocessors with a special software 2. A timer IC (like a 555) 3. PTCs/NTCs that heat up over time 4. Slowly charging/discharging capacitors Option 3 (SMD PTC/NTC) or Option 4 (multitude of caps on all boards) could apply to all of those, so I will not mention that. Let's go through all 3 amps: #1 @11:36 - Has an IC with a sanded surface on the left side (idk what they're trying to hide here), option 1 or 2 could apply here. The two ICs on the right side are NE5532 OpAmp-ICs (one IC contains two amplifiers, they went overkill here), but I don't think they would be enough to supply headphones. The through-hole connections on the back also look a bit weird, they usually expose some copper instead of having a solder mask. Conclusion: Probably legit. #2 @12:16 - Also has an IC (sadly I can't read it). Only one NE5532 this time, proper through-hole connections and another IC in a TO-220 package, most likely a voltage regulator (two pins would not suffice for a stereo MOSFET). Conclusion: Legit if it outputs stereo to two different channels. #3 @13:22 - This one is a bit weird, as it has a lot of ICs on it, half of which I don't know what they do. I guess some of them are charging/monitoring circuits for the batteries. We also got one NE5532, an XL6009E boost converter (makes lower voltage to higher voltage) to reach 12 Volts. Conclusion: I don't know, the green board looks sketchy. The white stuff on the back is just solder flux by the way, meaning unlike the other two it got actually hand-soldered. tl;dr: They could all be legit and I think they are. I need some help. To clear some myths: Tubes and their sockets have form-factors. They don't use all of their pins because they don't need them, most pins probably aren't even connected internally.
I'm former electrician technician from Hungary (former communist country where even the TV and radio bandwidth was different) who live who live in a USA and audio file. I'm interested in the things what I didn't see before 99% what you show. I don't care how you call it. Thank you for your hard work!
I really like this reply video. Super sassy replies, that were well deserved. A lot of people that never become fully invested in X hobby, are steered from the experience because of other enthusiasts. Specifically, the ones that chastise others for things like terminology, knowledge and questions about said hobby/interest. Just stop. We get it. You're awesome.
I hope negative comments will never discourage you from making more videos. I really enjoy your style of presenting. I learn a little with each video and you've inspired me to re-look at my hifi and think about making changes....although maybe I'll stay clear of these headphone amps ;-)
I'm not an engineer or particularly knowledgeable on electronics. I enjoy the general videos from Techmoan quite a bit. I also sometime enjoy videos that discuss things in a more technical way, although my level of understanding varies. These two things aren't in competition with each other, they go along with one another quite nicely. Mat makes a good point about the importance of fun, that's a healthy reminder that I need every once in a while. I think the stupidest thing about those comments is the Americans correcting a well spoken English person about his English pronunciation. The English language in America has changed from the original English in a lot of ways, for better and worse but in typical fashion there are many Americans who have no idea what they're talking about and think that just about everything in the world comes from there.
+ChillCosmos All to often, tech products come with a "Disassembling, reverse engineering, or tinkering with this product is prohibited" warning. This is so bad, it stifles innovation. How much of today's technology would exist if someone in the past had not disassembled, reversed engineered, or tinkered with their electronics? Louis Fender got ideas for his guitar amps by studying old radios and electronics manuals. His Champ was supposedly a modified circuit from a Western Electric tube manual. And his amps were studied, copied, and modified by just about every amp maker since.
+Doug Browning I don't think anyone that would want to take something apart to reverse engineer it would pay attention to such a warning. It's not like they are going to come to your house and throw you in jail for taking it apart. I don't think simply having such a warning on it "stifles innovation" at all. They are mostly only there to stop people that don't know what they are doing from electrocuting themselves anyhow.
+Kandi Gloss I think it may have more to do with the fact that a lot of tech today includes embedded software. Tinkering with that stuff can get your device brick-housed, and you may even be in trouble with the copyright police. However, most of today's programmers learned from examining somebody else's code. I don't think there's a programmer alive who can say they didn't play with an Apple II or similar system when they were kids. In the old days the warnings just pointed out that there were dangerous voltages inside the product, and often refereed to no user serviceable parts, and that you should take it to a qualified technician for service, TVs also added warnings about CRT implosion and x-ray exposure risks, but never actually prohibited users from tinkering with them. What you do with your own property should be your own business.
Try telling Big Clive not to disassemble, tinker or reverse engineer, and you could guess how obedient he would be. If he obeyed, there'd be no bigclivedotcom on MeValve.
The tubes are actually being used; 12 volts plate voltage is enough to run many miniature tubes in a "starved anode" configuration. That said, most of the gain is provided by the 5532 low noise op amp; the boost converter is generating the voltage for the IC, not the tube. The same circuit without the tube section would work just as well.
The PCB's are double sided and it seems that some of the tube pins are connected to components on the top side. Preamp tubes like these are often used with low plate voltage in guitar distortion stomp boxes and some cheaper microphone preamplifiers, the operation mode is called "voltage sagged" and can work alright, although most of the magic happens at way higher voltages as seen in properly designed preamplifiers. The "Little Dot mkIII" is a very popular and well sounding all-tube headphone preamplifier. The opamps are there to buffer the signal, tubes are high impedance devices.
These amps may have one or more voltage multiplier stages, my electronics knowledge isn't really good enough to tell, but the "gold" amp certainly has enough components on the board for that... a ditto on the double-sided board, and the amps may have more layers than that - PC's now operate with motherboards in the five to seven layer range!
Dear Techmoan. The thing that drew me to your channel was your excellent reviews of retro kit from the 70's and 80's. Little did I know that when I subscribed to your channel (which I did very quickly incidentally, after watching just two of your videos) I would be getting videos like this as well! Videos like this (and those brilliant the muppets videos), are pure gold and really do make me laugh very much indeed. Keep these up please, they are absolutely priceless - and of course, keep laughing at those trolls.
@@woodysgeekchannel2204 - I'll third that.... But fuck the Queen... (figuratively), monarchy is long passed its used by date. (I'm a British anti-monarchist btw....).
The 6N11 is a Chinese version of the 6DJ8/ECC88. It is a twin triode (three electrodes, cathode, grid, and plate; similar to the collector, emitter, and base of a transistor) originally developed as an RF amplifier for TV receivers. It is a nine pin miniature tube. The pins used are 3 and 8, cathodes; 2 and 7, grids; 1 and 6, plates; 9, internal shield; and 4 and 5, heater. The 6J9 is a triple triode, 10 pin miniature tube, originally used as an RF amp, oscillator, and mixer in FM radio receivers. It's pins are 3 and 10, cathodes; 2, 9, and 7, grids; 1, 6, and 8, plates; and 4 and 5, heater. The 6021 is an eight pigtail sub-miniature industrial twin triode used as an RF amp and oscillator. It's pigtails are 5 and 4, cathode; 7 and 2, grids; 8 and 1, plates; and 6 and 3, heater. I have no idea why they are using VHF RF tubes as audio headphone amplifiers, where audio tubes like the 12AX7/ECC83 would be more appropriate. I also have no idea what the ICs are for in those units, as the tubes alone should suffice in this application just as they did in the 1950's-60's.
The ICs are mostly likely being used to generate clock signals to boost voltage from that battery through that 6800 uF capacitor. Think Dickson voltage doubler. That's likely how a 12 volt power supply or that rechargeable battery can achieve enough voltage to push a tube.
+Doug Browning A lot of the headphone amp designs I've seen tend to pass the signal through the tube, then use solid-state components to provide the final drive current to the relatively low impedance headphones. Most tubes have fairly high output impedance, unless you're using a cathode follower...
Great video as usual. There isn't a video on TH-cam that doesn't get trolled or hated on in some way, please just keep producing great content and ignore the uninformed masses that comment before they have even watched the whole thing...
Mate I think you should stop obsessing over the TH-cam comments You can't make 100,000 people happy at once. Most of us love your content and don't care about a silly mispronunciation or whatnot.
While I agree, I actually found the teardown of the comments in this one very enjoyable. If he did that all the time it would get tiresome, but every once in a long while it's kind of nice.
I’m glad you brought up those comments. Some people take these things way too seriously. Keep doing what you’re doing and have a great time doing it. You make great videos, you’re having fun, and there’s lots of us who really enjoy viewing your creations. Thanks.
Great videos. I love these meta ones as well. Kudos to you for responding to all sorts of comments and not just ignoring them all as the rabble they may well be. TH-cam is a rough place to find respect, but you certainly deserve a helping or two for your approach.
LMAO. I love it. Tubes vs Valve. finger nails, touch vs don't touch. Priceless really priceless. You are always entertaining no matter what you talk about. Keep up the great work I really do appreciate all the hard work you put into these videos. -John
Dear Techmoan thank you for your great videos first of all. Addressing your questions - those tubes seem to be a part of the electric circuit and sound signal path. Circuit boards are double sided so you should not be confused with the fact that some of the pins are not connected on the one side. Whats a little bit disappointing is that the actual amplification is performed by an operational amplifiers and not the tubes, which are most likely connected as a cathode followers. Making a long story short - tubes are part of the signal chain but mostly for decoration and I would say marketing purposes (besides adding a little bit of distortion). You may find true full-tube devices with a higher price tag.
I know I am years too late here. But can I just applaud you for getting TH-cam Music Library music onto a cassette? Because that is absolutely fantastic.
Your videos are great. As a Canadian, your terminology sounds completely fine to me, including the word 'Tube'. I'm quite glad you skim over some of the technical discussions; I already know about matched impedence, what the mpeg-1 format is, and how CDs work; if not, I can always pause the video and spend sometime to look it up. To get a lesson on all that again in-video though would likely bore me, and sometimes I do skip chunks of your videos as a result. What I'm really here for is the same reason you enjoy making these videos -- playing with gadgets, technology, and all-around curiosity. Audiophiles spend a ton of money and time trying to get the very best audio experience, even if it is often a placebo or a matter of taste. Inherently, those types of people are naturally anal retentive. I wouldn't let them get to you; your videos are great and I highly enjoy them.
Your dry sense of humour and your love for electrical oddities are the reasons that keep me coming back to your great channel. A regular viewer from Austria (maybe the only one from there)!
I enjoy watching your videos. I grew up with tubes, and I don't know anything about tube theory either. But, I did have a tube amplifier, a Fender twin reverb that constantly crackled and spit. I gave it to my brother in law who plugged it in and left it running for a week. Now it is fine. No criticisms, just enjoy what you do.
The first amp has two ne5532p chips. Those seem to be common on headphone amps of all types. I just built one using two of those with no tubes.The second one only has one. What I find interesting is the amp that you said sounded the best uses two of the NE5532P chips and has the cleanest board. The other two only use one chip.
+Milosz Ostrow Yes, quite indeed. My favorite ones are: 1. My generation sucks/living in the wrong era 2. General snobbism about music, genre etc. Closemindedness. 3. Being rude to people who give free tutorials that they don't provide the info fast enough because they speak. 4. Thinking there opinion is a rule, not a matter of preference or viewpoint. 5. The bad kind of trolls who just want to be rude and impolite. 6. The people who think everything needs a label and that everybody who doesn't know what it means is a donkey. 7. The ones that have good info but brought by very, very , very angry people because someone made a mistake (we're all human) 8. The grammer nazi's who like to exterminate the ones that can't grammer. 9. The ones that just talk nonense with meme's/hypes like the whole lizard thing. 10. The ones that ask for attention (DOES ANYONE LIKE THIS IN 2015)... 11. The people that think this has something to do with something that somewhere in their lives and tell a very long story what ends in a beg for attention. I think I've got all that I think of....
+Jelte Derksen I was born in the wrong generation. Vinyl is the only way to really listen to music. Techmoan needs to talk faster. My opinion is fact. Fuck you. Everything needs labels. Actually you're not supposed to touch the tubes, goddammit Techmoan you piece of shit. *Grammar. Hissssssssss. DAE LIKE TH-cam VIDEOS IN 2016? Once upon a time, some relevant stuff happened, so like my comment.
+Milosz Ostrow I have found the opposite to be true as well, really, just like anywhere there are dicks and there are decent people. Just on the internet the dicks might be decent people irl and the decent people might be dicks.
These people are " nit picking " I'm in detroit Michigan and have NEVER had any issue listening to, comprehending, or understand your videos! Keep up the great reviews!!
You can only please some of the people some of the time. Keep up the great work, please continue with the common speak and the accent is part of the charm in the video. Please do continue to have a great time with your hobby!
I'm an electrical engineer so maybe I can clear a few things up. Low voltage isn't an issue here. See all the capacitors (labeled 16V)? (There is also an inductor.) Those are for a boost converter. Boost converters allow you to raise the voltage of DC with some tricks from AC electronics design. The circuit boards in those amps were double sided. So even though only a few of the traces are visible from the bottom of the board, on the top layer there are connections to the other pins. Please be careful with open tube amps because they utilize high voltages. The capacitors can retain the voltage after the device is powered down. Thanks for all the great videos! This is my favorite TH-cam channel.
I'm an audio engineer by profession. I have to laugh at these hi-fi guys. It's very much all snake oil and suffers from opinion riding over physics. Take a look in a professional recording studio. There's no gold plated connectors or £1200 IEC power cables there.. Keep up the great videos pal and thanks for your efforts..
+Andrew Kirkby I'm not a professional anything, but I quite like to do my own automotive work. 1) I find a sense of pride fixing my vehicle, 2) It's old and needs it often, so it saves me money, and 3) It's hard to find a garage that doesn't break more parts than it fixes. That being said... I hear people give me all kinds of vehicle advice, and much of it is snake oil as well. Telling me to put in additives and "HIGH POWER" spark plugs, telling me I should buy this or that to make the car work better. The truth is regular factory maintenance is what's important, no amount of snake oil will do a lick of difference.
+Jesse Crandle It's so true. Some things do alter your perception of sound but most listeners wouldn't know the difference and often those who say they had a better sounding system after an expensive upgrade have fallen short of the placebo effect to a degree.. I have a similar feeling about car repair. I do a lot of my own and tend to use manufacturer's recommended parts because that's what the vehicle was tested with and will likely get the performance I paid for when I bought it but adding expensive engine health additives etc will just burn the money you spent on them. A haynes guide to save the labour cost and a trip to a parts site like lings honda for instance is my robust solution... Unless the clutch goes.
Andrew Kirkby Best investment I've made in audio is a pair of Grado headphones. I had some SR80s, but after they broke I went to SR225s. The SR80s were a little lackluster in bass, so I went to the SR225s which has quite a bit more. A pleasant bonus was I could actually tell they were noticeably cleaner sounding, and the SR80s were already pretty impressive (coming from just sad Sony headphones that were 30 bucks, whatever you find online and in stores for less than $50).
6N11 and 6J9 are low noise amplifier tubes. The serials are Chinese variants in Europe the 6N11 is an EC88, and the 6J9 is a variant of a 12AU7 also a low noise amplifier. In my first valve amp, a CR Developments Kalypso 12AU7s were used as pre amplifier tubes, the power amplifier valves were EL84 - the big box(es) on valve amps are normally power transformers to drive the heaters in the valves. The Kalypso only produced 15watts total output which is why I used Triangle Comete loud spears with high impedance (I think they were around 96db) to get the best out of the amp. That was back in 1995. I was lucky to come across a pair of Quad valve amps from the 40's (which I had reconditioned) they used 500B power amp valves and were gorgeous. These were produced before the transistor was perfected in 1947. So yes Valves/tubes do work. They sound awesome though do 'colour' the sound, which I don't mind, I'm not that much of a purist, I like the warm tube sound.
Tube amps typically have an impedance transformer to step the impedance down from thousands of ohms at the plate of the tube to around 8 ohms for the speakers. At high power levels these transformers get large, heavy, and expensive to make.
As far as powering the tube, the current required is low, so these circuits can use a step-up ("buck") converter to raise the voltage from 12V. [Edit: confirmed; the tube is powered at 190V with a 6.3V heater]. The heater (a second circuit that powers the tube) is typically 6 or 12V, AC or DC, so good to go there. Finally, there is also the "Starved Plate" design where you don't run the tube at the highest voltage possible, but use a lower one. This can reduce noise and lead to extended tube life, although these small-signal tubes last a very long time (10,000 hours is typical). The Blue LEDs are somewhat bling-y, although the Chinese love an excess of bling, so to them it's probably minimally decorative rather than over the top as it might be seen in the West. There are diodes in the circuit, so the LED may simply be in place of a diode in the circuit that does not light up. In other words, possibly not useless as far as the circuit operation goes. I'm not suggesting these offer good, or even adequate performance; they are very cheaply made and little effort is made to increase or even address fidelity. Novelty items, but neat if you like that kind of thing.
Many years ago, I had an old consul stereo, she was cheap but the speakers were from an older consul and they were great quality. One day I was at an auction sale, and I purchased a Heathkit stereo receiver. She had dozens of tubes and I really wanted to know how it sounded, it must have been twenty years old back then. So I run the wires from the consul up to the amp, hooked up the record player which was a junker Gerard with changer, and played a few records. MAN what a difference! Those tubes changed an average consul stereo to almost BEING there! I loved it. It remained sitting atop that old consul stereo till my kids knocked the whole thing over roughhousing in the rec room in the basement where it lived.
I, like many others, saw your original value amp comparo and thought it was great. I loved the fact that you took the time to address many of the comments. I hope you don't let the negative comments bother you too much. Just do what you do best and let the trolls vent. I'm sure it's therapeutic and hopefully they feel better for it. And having lived in England for a number of years back in the 80's, I appreciate the more elegant and straight-forward way the Brits use language so please don't change that. Thanks for your efforts. I appreciate it. Subscribed.
Your sense of humour cracks me up! You could be talking about a block of cheese and I'd still be entertained! Keep doing what your doing and have a nice Christmas 😀
Techmoan, I think you are doing great. I like it that you explain things for the layman who would be lost with all the technobabel. Your videos are very informative and entertaining. I've learned a lot from watching your channel. Keep up the great work.
The thing with fingerprints is that the acid in the grease etches the thin glass thus weakens it and it can then crack, however, that is only valid on high power bulbs like Xenon headlight for cars where the rapid heatening may crack the glass where it's weakened. For tubes it does not matter due to it's thick glass and slow warming up, the grease does effect and tends to remove the usual white printning though, as moist also will do.
+senohpi Acid in the finger oils? Now that's a new one to me. Would have to be some seriously acidic stuff to etch glass... :D Now grease stains do have an effect on halogen bulbs and the like, but it's caused by the greasy spots heating up significantly more than the surrounding areas.
While why fingerprints on bulbs is bad, your theory is incorrect. In halogen bulbs and Xenon bulbs, fingerprints prevent proper cooling of filaments and cause them to prematurely burn out. It has nothing to do with glass expanding or contracting, and more to do with heat dissipation. I've burned out bulbs on purpose as a demonstration, never had the glass fail as a result of fingerprints.
+Richard Stifle just to be clear, I understand you do agree that the fact remains fingerprints have no effect on the sort of low power diode and triode tubes used in home stereo systems. Fingerprints do affect tubes that get incredibly hot, but not low temperature tubes found in these audio amplifiers and old TVs.
+senohpi You are right guys, i certainly mixed things up :)Regarding the halogen bulbs i suspect that the grease acts as a dark or reflective spot for a certain amount of the spectral energy that the filament emits, halogen have of course a very different distribution of the spectral energy than, for example the sun, has,thus gives insuffiecient cooling on that part where the grease is applied.Does it sound reasonable?.. i have to get a bunch of bulbs and do some experiments now :)
I prefer a tube/valve guitar amplifier. Never really considered one for just headphones. Thats audiophilia on a whole different level. Wow. Great video as always.
your original video was perfect... let the haters hate. think about all the view you got from people that didn't comment? probably because they thought that (as i did) the video was great a straight to the point at my level. and guess what... i didn't comment on that video.
In each amplifier seems to have a NE5532 chip. A quick google search shows that this is an operational amplifier. op-amps are great for analog computing, and "amplifying" signals, but they in general are not designed to drive speakers and stuff. Generally the output is limited to a few tens of milliamps (mA) at most. They're probably serving as pre-amplifiers. I would expect to see some boost converters inside all these to create at least a few hundred volts for the tubes, but I don't see any high voltage capacitors indicating that. However, all of them do seem to have switch mode converters, so maybe HV capacitors are present as SMD ceramics without values printed on them or something, IDK. Although unlikely, these could be multilayer boards with traces literally inside the PCB, explaining why there are seem to be pins that aren't connected anywhere. It would also be that the tube amp does not require the functionality of every pin. Some tubes might have more grids than are necessary for instance, or possibly some pins are simply not used and dont connect to anything internally inside the tube. (engineers like to stick to universal standards for case styles.) Same is true for solid state electronics, sometimes devices just have a few pins where are simply labeled NC for Not Connected.
I am going to GUESS looking at the electronics that they do use the tubes as output stages, considering I do not see any discrete transistors (SMD, TO92, or otherwise) to drive the headphones near the output jacks. I don't think op amps are powerful enough to do that, not at high volume, anyway. I could be wrong though.
+Power Max Well there are some inductors present, and also a smaller 8 pin device that has had it's part no. scraped off. Maybe that's the boost circuit.
TH-cam comment sections are almost always full of junk. But you said your original video even had an intelligent discussion, so that's great! You should probably heed your own advice from the end of the video and don't get too upset about all those comments. There will always be haters, stupid people, and those with a short attention span. No wonder the term "TL;DR" is pretty popular these days. I know taking criticism is hard. But it's even harder if one also takes to heart stupidity or lack of attention that is not really criticism. Sometimes it's neither, but just a serious question that meant no harm. Don't worry, your videos are great. They're on a professional level. I like every single one, even when they are about cameras that don't really interest me. They're still fun to watch. Continue what you do. Me and your thumbs up/down ratio are telling you you're doing it right :) Thanks!
Thank you for so much enjoyment! My teacher used to say that sarcasm would not bring me anywhere in life. This is probably not true but wherever I end up with my sarcasm I will be meeting you there. Drinks are on me. Looking forward to your next video!!
While I can't say for sure without reading the markings on the chips, all three units seem like hybrid designs. The valves are powered and seem to be used as a pre-amp stage while there are digital op-amps for actually increasing the audio signal. This would make sense because the valves would need more power than digital circuitry to increase the audio signal than the op-amps would. This is done mainly because as you up the power to get the valves working you would need better rated components to cope with that plus extra heat generated within the units. A hybrid design in this case becomes far less costly than a pure valve one.
A hybrid is also more efficient, because using tubes as power amplifiers requires a hefty (and not at all safe to poking) B+ voltage. The beefiest caps I saw in the teardowns were rated at 50V, so the B+ rail would have to be less than that and audio tubes really want a few HUNDRED volts to really cook. If they're just being used as lower power pre-amplification, then you don't need nearly so much voltage -- but it also defeats the purpose of using tubes because they're not being driven anywhere near saturation. Everything that is not defective sounds about the same in its linear range. It's what they do when pushed out of the linear range that makes all the difference. In other words -- the tubes work, but they aren't doing anything to the sound because they have to be pushed to do that and these circuits simply can't. Personally I aim for reference everything. No EQ or tone controls, speakers or headphones that are as flat and uncolored as possible, no surround effects or enhancements, etc. It does mean my setup is not at all "forgiving". Bad recordings sound like bad recordings. (In such cases, I may cheat and use some EQ.) But the way I see it, how can I go wrong trying to match actual studio gear as closely as possible? Why shouldn't I hear what the engineer intended for me to hear? I also engineer my own music on the same system: a 160W solid-state amplifier which I don't push even halfway there, a pair of Tannoy SRM12B monitors, and modified Sony MDR-V600 headphones (modified to eliminate their "bass boost" and make them behave more like the MDR-V6). I do have a consumer grade entertainment setup as well, and I listen back to my music to make sure it doesn't get totally destroyed, but honestly it's not my lookout if someone pushes my tunes through shite hardware.
@@mal2ksc Lots here; but a couple of key things: 1. it's unlikely your listening space is close to the acoustic surroundings of the studio control room where the music was mixed. 2. Generally speaking your listening to the output of a mastering engineer, not the mix engineer and 3. We all have different tastes, some like more bass, others like more highs. either way, what you're striving for is a preference, one that the mastering engineer had but not necessarily yours. Give two mastering engineers the same stems and you'll end up with two different outcomes, neither are right or wrong, but different they will be.... Still sure your setup is optimal...?
Techmoan, here's a pseudo-latin phrase for you: Illegitimi non carborundum. That is supposed to mean: Don't let the bastards grind you down. Just keep doing your thing. You're are doing a good job and you are being honest and that is refreshing.
I'm glad you went back and called out everybody that didn't pay attention and all the snobs. Love your content. I have no problems with anything youve done or will do. Keep it all up.
The circuits look legit from a first look. The NE5532 chips look to be used as pre-amps before the valves, all the electronics seem to be fully analog from what is shown making a dummy delay circuit unlikely, the small surface mounted chips look like part of the DC-DC step up converters as valves generally need a high voltage to operate. There are exceptions to this of course. I agree hobbies are for enjoying, tinkering with electronics and computers is very much fun for me. Good to see you don't worry about the Ellettest numptees, I tend to find such individuals amusing.
@Philip Turner - I'm a guitarist too... And always use my trusty valve amps. But being thermionic valve trained (rado comms) furnishes me with a modicum of technical understanding. Technically, it is all down to 'odd harmonics' a factor of thermionic valve characteristics. The 'clipping' (distortion) created by semiconductors is very 'harsh' - or square-wave as a function of the 'even' harmonics of the component in use - transistors. Whereas, thermionics clip at the 'odd' harmonics, which creates a much *rounder* clipping characteristic. Simply put - valves/tubes/bottles distort across a broader bandwidth, where the clipping is not so square waved, so they sound less harsh. An important consideration when using Hi-Z reluctors (magnetic pickups) with a broad frequency response and high amplitude. This same characteristic, also explains why valve HiFi amps sound generally more pleasing (warmer) to the ear than their semiconductor cousins. Of course, the new (ish) development of 'amp modelling' is an attempt to emulate those valve characteristics, with varying degrees of accuracy and success. But that signal is still going through a semiconductor or hybrid signal chain, where that even harmonic distortion is ever present. Transistors just can't cut the mustard when it comes to playing a guitar through an amplifier, certainly not a high power levels. Any thermionic device - such as a valve radio, radiogram/record player, or tape recorder can be used as a really decent valve practice amp. Simply hook up your guitar to the Hi-Z input (or if your guitar is active, use the line input) and you're good to go.
@@acerbicgeoff7821 It's not a neat solution cos they're not actually valve amps. The valves don't amplify. Signal passes through them, but in a way that's basically cosmetic. They don't have the "valve sound" guitarists like. For headphones, is a little transistor amp so bad? If people perform with them, they should be good enough for practice right? And any practice amp, any two amps at all, are gonna sound different. So does it matter to get a valve one? Finally, don't guitar amps usually have headphone sockets?
@@greenaum I understand your point, and yes they do, but if I want to go out in the backyard, I don't generally like dragging my amp out and laying down a drop cord just so I can drink and chain smoke out of the way of the family. You are right it's basically cosmetic, and my current solution of a headphone amp that literally runs on batteries and stays connected to the guitar is far more portable, but others might like the little gadgets too. It's all preference
@@acerbicgeoff7821 No I mean in THESE amps the valves really ARE cosmetic! They're NOT VALVE AMPS! I can't remember exactly from the teardown, but basically signal passes from one plate to the other, in these. In a normal valve amp, the valve is an amplifying element, and in doing this, the valve's nature affects the sound. These are purely silicon op-amp amps! They're a ripoff, is the point. They won't sound like what you're expecting. A little portable valve amp might be nice. It'd probably cos you though. You'd need a few PP3s to power it, the simplest way. Whatever. It could be done. But not as cheaply as in these, and certainly not as shitly! They're a ripoff mate! Purely cosmetic as in visual cosmetics! The valve is in-circuit but not actually modifying the sound signal, AT ALL!
Techmoan: Ignore the elitists who have big egos! Yes, they are correct in mentioning some of the nomenclatures you mentioned in this video package, BUT it's your video, do as you wish...those who criticize have nothing better to do than watching and being snobs. The work you do with your writing, camera angles, editing, narration, lighting as well as subject matter is "TOP NOTCH"! Please keep up the great work! And remember, as I'm sure you alread know, you can't please everybody, but you should please yourself.
Don't feel bad, it's not just you, or even "HiFi people", it's the internet in general. I remember a fairly recent event where quite a high profile TH-camr had the audacity to buy a goldfish for the first time, and of course vlog the whole thing. She was utterly eviscerated by a gang of internet thugs from the self-declared "fish community". It drove her to tears and made her feel obligated to post a sickening "apology video", where she prostrated herself before the world just because she committed the heinous crime of putting something most cultures consider to be little more than a snack into "the wrong sort of tank". But yeah, HiFi nutjobs are just as obnoxious. They're just not particularly unique.
I know this is an old video now, but do people not realize that some people are also hard of hearing??? I’ve been using headphone amplifiers for years. There’s another reason for you. Thank you for calling out these mouth breathers. And not censoring their names. 👍
Ive been watching your shows for years now and I only managed to see this one now (thats COVID-19 lockdown for you). TH-cam comments, for some strange reason, can be particularly nasty and i've seen some of the unkindest things mentioned in the posts. I have always felt a bit of pity for the youtube creators putting the effort they do into these videos (and theres a lot that goes into it!) only for some 12 year old to tear it apart. Dude your shows are great! Never change them :) Oh and when it comes to audiophiles your'e opening a pandora's box. As a sound engineer I take a pretty pragmatic approach to audio, there are no rules to all this, even the noisiest pre-amp serves its purpose somewhere. Life is just too short to over think this all :D
i have TONS of respect to you! i generally like people from england but the fact you just went half the video length to breake down these stupid comments is awesome! i've never seen someone doing that and u have tons respect to us as i see 🙄 keep doing what you love
You put sooo much effort to tear things down to ignorants, less intelligent people. I respect that, i really do! Many thanks for all the enjoyment that you are giving to us through all those years, precious moments all over you well-constructed videos.
My brother is a guitar player. He swears by tube amps. He said the sound is "warmer and more alive". When I was in grade school, I had a nice tube radio in my room. The back was missing, but that was fine. I used to turn it around so you could see the gentle glow when the lights were out.
Don't let these passionate nerds get to you. They will pick apart every little thing. That is why they don't socialize very well. Keep up the good work!
You really inspired me to start experimenting more with my hifi setup. Before i watched you i would never put a cheap Chinese thing like that in my hifi and now i did. I bough one of those cheap 6j1 kits on aliexpress, i replaced the tubes with better ones and put some brand name capacitors in it. I use it with my cd player that i always thought sounded too bright, now it sounds a bit richer.
![[LIVE] : ONE ลุมพินี 88 | คู่เอก "ป้อมเพชร vs อัสลามจอน"](http://i.ytimg.com/vi/1ZqTVVbMgbo/mqdefault.jpg)
Techmoan channel - Content is good. Reviews are good. Pronunciation is good. Terminology is good. Enjoyment factor, at this end, is good. So, all in all, all good. Thanks for all your hard work Mat. It is much appreciated.
Couldn't have said it any better than that.
what can you say about the comments? :D :P
I realize it's kind of off topic but do anybody know of a good site to watch newly released tv shows online ?
@Mayson Kade flixportal :D
@Korbyn Alec thank you, I went there and it seems like they got a lot of movies there :) Appreciate it !!
Hi, electrical engineer here.
Gold Xuan Zu: the circuitboard is a combination of through-hole components (soldered THROUGH the circuit board, mainly on the right) and SMD components (Surface Mount Device soldered ON the circuit board mainly on the left) which is why they don't seem connected if you look on the back. It uses HQ surface-mount capacitors which filters the high/low pass frequencies and along with the tubes/valves (which act like old-school transistors) creates the analog vibe. The two IC's at the front are (digital) dual amplifiers and actually seem high grade. Generally the circuit is of very high quality and an amazing finish for a budget tube/valve amp. So no suprise on actually being better.
Zhilai: "A worthless heap of shit" as my favorite Aussie EEV-blogger likes to call them. All of the capacitors are of terrible quality and one of them is already busted (the electrolytic caps as we call them have fluids inside that swell up after time). Not worth explaining the rest. Garbage.
Little Bear: What. The. Actual. F*ck? Almost ALL of the components are obsolete/refurbished, it's a wacky mix of horizontal and vertical circuitboards probably to cram all that circuitry inside. All I see is trouble. Not much to add.
gigglygigglydude Could you comment on the new little bear b4 as I would love to see what you think of it’s internals?
Agree with all of gigglygigglydude's comments and would like to mention that a better set of tubes will probably get rid of the microphonics in the Gold Xuan Zu amp as this is a mechanical issue with the internal components of the tube.
might be wrong but it looks like they might be using a switching boost converter to jack up the voltage to run the heaters and just filtering out the noise post amplification, at least on the first two. Don't know much about tubes, but i'm not sure what else that other little smd chip could be doing. agree with giggly, xuanzo looks descent others are junk
Well, there is nothing "digital" on the Op-Amps, as it is analogue in and analogue out. Per definition, as tubes are of course analogue. First amp looks the cleanest build. Little bear components obsolete/refurbished: no, it is just the standard Chinese junk. Nothing valuable enough to salvage / refurbish. Wacky mix: I guess you never saw electronics in confined spaces before? Signed, a real electronics engineer.
gigglygigglydude Thanks so much - really appreciate the knowledge. Went and bought the amp you recommended cos I want to do my toe in the water without spending a ton. Please keep helping people with posts like this.
The most well-equipped high end home electronics store in my city is easily one of the least welcoming places I've ever been to. Watching that "HiFi Shop" sketch definitely reminded me of being condescended to by old dudes who were very proud of their vast knowledge that they were blessed with at birth. I appreciate your sincerity and your enthusiasm for plain speaking. Carry on, Mat!
10:49 "Ya sorry about the breathing there, it's something that I do from time to time. I've been trying to stop, but it just seems to keep happening." Very good sir, and watching this now in 2019, you were saying tubes fine as far as I am concerned. We all have accents and if literally everyone knows what you are saying, they are just being rude. Anyways thanks for the content.
Next time use a minidisc player. That will really drive the purists nuts.
With ATRAC compression turned up to max! (equiv. to about 64kbps MP3 if I recall rightly).
They'll be foaming at the mouth!
I am listening to music from TH-cam, using earphones-with-microphone, plugged into the front jack on the pc.
Na, use your Tififon!
Next time plug into a potato.
128MB Mp3 player will just do it
***********TEARDOWN TEARDOWN TEARDOWN TEARDOWN*********
There is a choice to make... You can either be
A) The 50th person who links to the eevblog teardown video
B) Someone who reads comments & click here th-cam.com/video/coSt5HWRvv4/w-d-xo.html
+Techmoan my only concern was the price of the units as i have a ok valve amp but the valves cost around £10 each So i couldn't see how the ones you tested were going to be much good.
+Techmoan EEVblog (David Jones) in Australia did a TH-cam technical tear-down of the gold valve amp, shown at 11:38. The valves in it are hard wired as cathode follower triodes. Thus, they have no voltage gain, but will operate on voltages as low as 12.
+Stephen Clementson so you went for option A did you?
+TheBaconWizard Dave Jones (EEVBlog) drew a circuit diagram of that amp, which showed that the valves (tubes) did not provide any amplification. Even the buffering they provided served no purpose, and it was clear that the valves could be bridged out of the circuit. Bridging the valves out would undoubtedly reduce the distortion. Not worth the cost.
Stephen Clementson Correct. So option A, then.
I loved the use of the Walkman in response to using a Pono. I actually physically laughed from that. Thumbs up.
A blast from the past. But I thought the cassette was the most intriguing thing I saw.
A good thorough layman's review (and easy video to watch too). Some times you find out they're duds. That's the point.
Man I love how the first 7 minutes is roasting the comment section lol
And the last 7 seconds is effectively a ‘death threat’, lol 😂
Also, these are multi layer circuit boards. The tracks on the bottom are only parts of the traces going to the tubes. Look carefully art the top view. There may also be traces in between layers.
I was about to comment this, but I scrolled down a bit to see if it had been mentioned. You've hit the nail right on the head.
A few short comments (I don't like typing a lot):
In the late '60s I watched my father and uncle build hi-fi and electronics kits (Knight, Scott, Dynaco etc.)
From early to late '70s I built Heathkits and Eico, and worked in TV repair shops.
I got to the point where I can look inside a tube and identify which leads go to the anode, grid(s), cathode, heater etc.
Came in handy when the ID was rubbed off.
Never worried about leaving fingerprints on the 1000s of tubes I handled.
In fact skin oils on the higher power tubes only made a distinctive odor.
Looking in my 1973 RCA Receiving Tube Manual I see that the 6J9 is a high mu triple triode.
Doesn't list the others mentioned.
To those who like the sound of tubes I say "have at it", the added distortion is like the fungus in a good cheese.
Nicely put
The 6021 subminiature tube is a twin triode. It looks like it was high quality as it was one of those subminiature tubes that were built to US Military specs back then. It was used for RF Amplification and Oscillation.
maybe we should call youtube "youvalve" from now. :-)
And therefore at this moment I shall declare this comment by +Johan Ouweneel as the best reply for all those who paid their attention to the unrelevant on the previous video on this topic.
+Johan Ouweneel or youpipe
+Johan Ouweneel
no.
these are different "tubes". youtube is called after a tube which is not a valve.
Oh. You're just being silly.
+Silly Sad No it isn't. It is named after a cathode ray tube (as in TV) which IS a valve.
I'm no engineer (yet) but from what i know and can see a) all of them send the audio through the tubes, but are not necessary using them for amplification (microphonics are a clear sign the audio is going through, but the tubes could just be configured for a gain of one), b) all of them have ne5532 dual op amps, that probaply do the actual amplification.
On the gold one it seems to be pretty obviously using one on the input and one on the output, so probaply in->opamp->tubes->opamp->out, the tubes probaply have no or almost no gain, just to colour the sound. COuld be that they actually do the gain an the output opamps are just used as buffers.
There are coils and some smd chips on there, together with a bunch of caps, so that's probaply a power supply section, but as the caps are all 16 or 10V ratet it's not gonna be a step up converter, my guess would be switching step down to power heaters, so they don't generate to much heat as they would with regular linear regulators.
The silver one has only one ne5532, so only one solid state stage, the smd device at the rear is probaply a buffer for the line in. There is angain an inductor with that to220 package device stuck on the back, so again probaply voltage drop, but this time probaply just a 78xx linear regulator and the coil for filtering something, but only one this time, wich makes sense because only one tube... wich makes me wonder, why the golden would use 2 separate power supplys for the heaters, normaly you would just put them in series and power them with a higher voltage (generally 6V or so per tube on those, so 12V, wich I would guess is also the input voltage), so maybe the re is just some power filtering on the golden one, who knows...
The little bear looks really bodged together from modules, obvously the battery indicator on the rear panel, battery charger/protection on the thin part and the green module actually looks like a voltage converter, but it seems to be a step down converter from what I found, probaply again to run the heater more efficiently.
Again only one ne5532 but some damn huge capaciators, much more like in a decent, powerful audio device, so either the circuit pulls a lot of current spikes or the battery converter generates a lot of noise. Also, two of those caps seem to be nichicon, wich is one of the top brands and I would not expect those in a device as ceap and shoddy as this, so could be fake.. then again, it looks like something built by some single dude in his basement, so maybe he got genuin ones because he knew they were better... probaply not though.
About running the tubes with low voltage, while all of these are ment to be driven with 100s of volts, a lot of those small ones can operate on low voltages, even 10 and lower, but the possible output power drops significantly as well as amplification headroom, as there will be much more distortion (called operating in starved plate modey sometimes used as an effect for guitar sounds), but as a weak preamp/unity gain stage it should work
That's what came to my mind, hope im not talking bullshit
Very interesting! Thank you for your input!
Very competent analysis, grateful of your essay.
Good read. Hope you got your engineering degree.
Also, I can't help myself;
probably*
Correct, they are not doing any amplifications, thats all left up to the op-amps(NE5532), the signal is passed through however.
Even if they were used at low voltages, they would be firmly on the lower part of the gain curve where they are very unlinear.
i just want to say as a 22 y/o who is slowly getting into the HiFi scene (especially headphones), I really enjoy your videos and i find them very entertaining! I'm on a binge of watching at least 10 of your videos a day for a few days now and i have no intention of stopping. I love how in depth you go into the small things that are good and bad about each product. Also i love how you handle the haters lol. Keep making great content Matt, most of us really enjoy your time. God Bless
I've been watching your videos for a while they are great and informative as your opinion is based on what you have in front of you. I've personally been more involved in my HiFi passion in the past years with a complete CD / Turntable setup in the living room and a vintage cassette player in the kitchen. As I was doing researches about audio equipment when I first got into HiFi, reading online and going to audio stores, I got sucked in the HiFi world / community where everybody knows best. I can't stress this enough, most people who are into HiFi are taking it way too seriously and are very opinionated. At some point, I realized most of all opinions you get from those fanatics are rubbish and I learned to appreciate the time and care people put on their setup instead of what type of brand or equipment they own. Lets face it, you dont need 20,000$ of audio equipment to appreciate music.
A lot of the HiFi enthusiasts seem to never listen to music...they just argue about the best way to listen to it. Meanwhile I'm enjoying an 8-track.
I don't need $20,000 but it sure would help...
Do what you like. Ignore the trolls.
I do what I like...but I laugh at the trolls.
Laughing at stupidity is not the smarter approach.
But its the more fun one
PlebzOr Blapparapp
Why, thank you!
many people comment part way through a video, dont realise its been said later on, and dont bother editing their comment, that or they stop watching half way, who knows, many viewers are about 16 and have never heard of a valve or anything that isnt an ipod shaped object
The problem, I think, is that for some people, being angry on youtube *is* their hobby.
"You nailed it." -- seems appropriate again!
@tone167 - Sometimes the upload warrants some backlash though. Not to mention the shear number of brain-dead morons that comment. ... But one has to be selective in one's response. On uploads such as this and mostly other electronic or technical/DIY uploads, good etiquette is appropriate. But when one comes across an upload that is spouting bullshit, then one straps on the Colts, dons the poncho and flat-brimmed hat, boots and spurs, stuffs a Virginian in the gob and walks out onto the dusy street, with a determined countenance.
Hey man, you can't get bent out of shape over youtube comments. you will never be able to please everyone. I think your videos are nice and a good mix of technical and plain english.
Keep doing what you do, you do it well.
Excellent follow up to a great video. Although strictly speaking the guitar music at 8:21 should have been on a left-handed 12 string guitar, otherwise it sounds like rubbish and is a waste of money.
😂
ROFL!
Thank you - that was a good laugh!
That is why Jimi Hendrix died when he started to play right handed.
I'm just a southern boy in the US and found your videos very informative and your accent pleasing, piss on those who criticize on detail and being politically correct. Most of the comments I read just shows that some folks have no electrical/technical background but yet insist on commenting about something they know nothing about. Funny how kids these days can search the internet for anything and still learn nothing.
I'm have EE background myself and always enjoyed your presentation method. Learned a lot from your videos.
Layman's terms or understandable words is best communication for general public.
Just do what you're comfortable with.
We subscribed due to that.
I'd turn away if your presentation was too technical.
Hey Techmoan! I have a degree in electrical engineering and nuclear engineering, so I took a close look at all three of the devices you have here to see if I can help you out a bit. I specialized in control systems and power distribution, so this isn't *quite* my area of expertise, but I'll see if I can take a crack at this.
The IC chips that you see on the boards are NE5532 Op-Amps. It seems as if the IC's are working as a pre-amp and the signal that they output is fed to the tubes to boost the signal. I believe you refer to this as a hybrid amp.
The two-tube amp has a separate op-amp and tube for each audio channel while the single tube amp has a single, dual channel op-amp and a single, dual channel tube. The single tube is pretty much just a two-in-one solution. Either way, both amps provide stereo hybrid sound.
The pocket amp does the same thing as the others as well, but has a micro-tube and some dodgy components, leading to the lesser quality sound.
Hope this helps!
+Classical Rips Hello fellow engineer!
Indeed, there are opamps are inside each amplifier. Probably for coupling _chube_ output impedance to lower *impedance* of headphones. Choobes do amplification, opamps do coupling here, just my guess. Anyway that means they are hybrid and not cool enough and basically an abomination for a true audiophile.
No sign of poweramp (_post-amp_, really?) ICs though as they usually come with heatsink pad even for a small headphne amps. The second (blue one) has something with a heatsink on a bottom side, but probably that's a part of power circuit.
PS. CHUBE-CHUBE-CHUBE-YOUCHOOBE. Hope you forgive me for a little irony, Mat ;)
+Classical Rips yes, thanks for the info.
A pair of NE5532 (and many other) op amps are quite capable of driving stereo headphones all by themselves. The tubes are window dressing.
I built my own tube amp with pencil tubes for the fun of it. Tubes are high impedance devices while headphones are relatively low impedance. The NE 5532s are being used as the outputs as they have a high impedance input but low impedance output. The only other way to get an output from a tube that could drive most headphones would be to use an audio transformer which adds weight, complexity, and low level distortion.
Whatever you do, don't change your presenting style Matt. Love the lost format stuff and hope you wont stop once your audio and video cabinets are full. I love the fact you try stuff out, its always interesting. I have no interest in dash cams, but I haven't missed an episode! :-) Compulsive viewing.
+Paul Grimsley ive got plenty more things to show. Two large parcels turned up this evening and hopefully if the contents work they'll be used in some HiFi videos next year.
+Techmoan Excellent, Thanks for the reply Matt. I hope you continue your logical stance on audio demonstrations too, maybe with a quadrophonic a setup review! As far as I know TH-cam can't output audio in quad....? :-). All the best.
Welcome to audiophile land. You'll hear from people admonishing you for not polishing your tubes, or how you muststoring them in a freezer when not in use. While I know the actual proper way to use tuvbes is to have pure clear quartz rock crystal the, each weiging 25 grams apiece (very critical) 120 degrees apart Exactly 25 mm from each tube. Otherwise, the sound doesn't reflect properly, and you'll get listening fatigue. And forget about it is you use anything but a Zinc carbon battery to power them. Lithium batteries introduce serious temporal distortion
LOL - Temporal distortion. Excellent comment!
Mine are positioned on ley lines. No one serious about their audio would do a review without mentioning this. ;-)
Don't forget to polish nice and hard your mpingo woodie ,shunmook wouldn't have any other way.
not gonna lie you had me going for a second thumbs up to your comment.
OMG - You need to elevate your interconnect and power cables off of the desk at least 3 inches and at least 90% of the run aligned parallel with the equator.
First time to your channel and your feedback on the comments is exceptional and the amount of detail and effort gone into them is what most people need to do. It’s great because anyone who doesn’t have a chip on their shoulders or will actually watch the video in its entirety before making a comment should appreciate your effort in trying to share an interest and that’s it.
"...remember to enjoy yourself, it's later than you think." Very wise words, Matt.
Electronics APPRENTICE/ENTHUSIAST here (I AM NOT A PROFESSIONAL), I will try my best and to keep it simple:
In order to simulate a delay, you have the following options:
1. Microcontroller or microprocessors with a special software
2. A timer IC (like a 555)
3. PTCs/NTCs that heat up over time
4. Slowly charging/discharging capacitors
Option 3 (SMD PTC/NTC) or Option 4 (multitude of caps on all boards) could apply to all of those, so I will not mention that.
Let's go through all 3 amps:
#1 @11:36 - Has an IC with a sanded surface on the left side (idk what they're trying to hide here), option 1 or 2 could apply here. The two ICs on the right side are NE5532 OpAmp-ICs (one IC contains two amplifiers, they went overkill here), but I don't think they would be enough to supply headphones. The through-hole connections on the back also look a bit weird, they usually expose some copper instead of having a solder mask. Conclusion: Probably legit.
#2 @12:16 - Also has an IC (sadly I can't read it). Only one NE5532 this time, proper through-hole connections and another IC in a TO-220 package, most likely a voltage regulator (two pins would not suffice for a stereo MOSFET). Conclusion: Legit if it outputs stereo to two different channels.
#3 @13:22 - This one is a bit weird, as it has a lot of ICs on it, half of which I don't know what they do. I guess some of them are charging/monitoring circuits for the batteries. We also got one NE5532, an XL6009E boost converter (makes lower voltage to higher voltage) to reach 12 Volts. Conclusion: I don't know, the green board looks sketchy. The white stuff on the back is just solder flux by the way, meaning unlike the other two it got actually hand-soldered.
tl;dr: They could all be legit and I think they are. I need some help.
To clear some myths: Tubes and their sockets have form-factors. They don't use all of their pins because they don't need them, most pins probably aren't even connected internally.
+NKN1396 "An excellent comment"™
+NKN1396
#1 Yeah the hair rose up on my neck.
#2 Agreed.
#3 See #1.
+Yu Lei I'm crying with laughter reminiscing about all the Chef Excellence shit. God, I miss Ashens. I'm going to head over there now.
Is life real ,or is it just shadows on a cave wall?
+NKN1396 And you forgot valves. The grid needs to be heated to emit electrons.
So it DOES take time at the beginning.
I'm former electrician technician from Hungary (former communist country where even the TV and radio bandwidth was different) who live who live in a USA and audio file. I'm interested in the things what I didn't see before 99% what you show. I don't care how you call it. Thank you for your hard work!
Long live communism
I really like this reply video. Super sassy replies, that were well deserved. A lot of people that never become fully invested in X hobby, are steered from the experience because of other enthusiasts. Specifically, the ones that chastise others for things like terminology, knowledge and questions about said hobby/interest. Just stop. We get it. You're awesome.
I hope negative comments will never discourage you from making more videos. I really enjoy your style of presenting. I learn a little with each video and you've inspired me to re-look at my hifi and think about making changes....although maybe I'll stay clear of these headphone amps ;-)
I'm not an engineer or particularly knowledgeable on electronics. I enjoy the general videos from Techmoan quite a bit. I also sometime enjoy videos that discuss things in a more technical way, although my level of understanding varies. These two things aren't in competition with each other, they go along with one another quite nicely.
Mat makes a good point about the importance of fun, that's a healthy reminder that I need every once in a while.
I think the stupidest thing about those comments is the Americans correcting a well spoken English person about his English pronunciation. The English language in America has changed from the original English in a lot of ways, for better and worse but in typical fashion there are many Americans who have no idea what they're talking about and think that just about everything in the world comes from there.
English “person”
The "Don't switch them on, TAKE THEM APART!" comment is actually a popular phrase that Dave from EEVBlog uses.
+ChillCosmos All to often, tech products come with a "Disassembling, reverse engineering, or tinkering with this product is prohibited" warning. This is so bad, it stifles innovation. How much of today's technology would exist if someone in the past had not disassembled, reversed engineered, or tinkered with their electronics? Louis Fender got ideas for his guitar amps by studying old radios and electronics manuals. His Champ was supposedly a modified circuit from a Western Electric tube manual. And his amps were studied, copied, and modified by just about every amp maker since.
+Doug Browning I don't think anyone that would want to take something apart to reverse engineer it would pay attention to such a warning. It's not like they are going to come to your house and throw you in jail for taking it apart. I don't think simply having such a warning on it "stifles innovation" at all. They are mostly only there to stop people that don't know what they are doing from electrocuting themselves anyhow.
+Kandi Gloss I think it may have more to do with the fact that a lot of tech today includes embedded software. Tinkering with that stuff can get your device brick-housed, and you may even be in trouble with the copyright police. However, most of today's programmers learned from examining somebody else's code. I don't think there's a programmer alive who can say they didn't play with an Apple II or similar system when they were kids. In the old days the warnings just pointed out that there were dangerous voltages inside the product, and often refereed to no user serviceable parts, and that you should take it to a qualified technician for service, TVs also added warnings about CRT implosion and x-ray exposure risks, but never actually prohibited users from tinkering with them. What you do with your own property should be your own business.
Try telling Big Clive not to disassemble, tinker or reverse engineer, and you could guess how obedient he would be. If he obeyed, there'd be no bigclivedotcom on MeValve.
Actually, EEVBlog did a reverse engineering to one of these amps, and "The tubes! They do nothing!" (almost): th-cam.com/video/coSt5HWRvv4/w-d-xo.html
The tubes are actually being used; 12 volts plate voltage is enough to run many miniature tubes in a "starved anode" configuration. That said, most of the gain is provided by the 5532 low noise op amp; the boost converter is generating the voltage for the IC, not the tube. The same circuit without the tube section would work just as well.
The PCB's are double sided and it seems that some of the tube pins are connected to components on the top side.
Preamp tubes like these are often used with low plate voltage in guitar distortion stomp boxes and some cheaper microphone preamplifiers, the operation mode is called "voltage sagged" and can work alright, although most of the magic happens at way higher voltages as seen in properly designed preamplifiers. The "Little Dot mkIII" is a very popular and well sounding all-tube headphone preamplifier.
The opamps are there to buffer the signal, tubes are high impedance devices.
Søren Hammer In fact they behave similar to FETs.
These amps may have one or more voltage multiplier stages, my electronics knowledge isn't really good enough to tell, but the "gold" amp certainly has enough components on the board for that... a ditto on the double-sided board, and the amps may have more layers than that - PC's now operate with motherboards in the five to seven layer range!
So they look cool! :D
There are two types of amplification - voltage amplification and current amplification. The tubes amplifies current. They are NOT eye candy.
I’m curious as to why you typed all of that out.
Dear Techmoan. The thing that drew me to your channel was your excellent reviews of retro kit from the 70's and 80's. Little did I know that when I subscribed to your channel (which I did very quickly incidentally, after watching just two of your videos) I would be getting videos like this as well! Videos like this (and those brilliant the muppets videos), are pure gold and really do make me laugh very much indeed. Keep these up please, they are absolutely priceless - and of course, keep laughing at those trolls.
I 2nd that. Great video ol boy. God save the queen and all that..LOL
Hear ear
@@woodysgeekchannel2204 - I'll third that.... But fuck the Queen... (figuratively), monarchy is long passed its used by date. (I'm a British anti-monarchist btw....).
Excellent comment *Alan J Woodward* - My sentiments entirely. And you gotta love those two muppet Dudes.
Bonus tip, though, always make sure to keep the plate axis of your tubes aligned with the Earth's magnetic field for extra audiophile quality. 👍 👌
If you don't have £30 000 cables, you can straight out forget enjoying music.
The 6N11 is a Chinese version of the 6DJ8/ECC88. It is a twin triode (three electrodes, cathode, grid, and plate; similar to the collector, emitter, and base of a transistor) originally developed as an RF amplifier for TV receivers. It is a nine pin miniature tube. The pins used are 3 and 8, cathodes; 2 and 7, grids; 1 and 6, plates; 9, internal shield; and 4 and 5, heater.
The 6J9 is a triple triode, 10 pin miniature tube, originally used as an RF amp, oscillator, and mixer in FM radio receivers. It's pins are 3 and 10, cathodes; 2, 9, and 7, grids; 1, 6, and 8, plates; and 4 and 5, heater.
The 6021 is an eight pigtail sub-miniature industrial twin triode used as an RF amp and oscillator. It's pigtails are 5 and 4, cathode; 7 and 2, grids; 8 and 1, plates; and 6 and 3, heater.
I have no idea why they are using VHF RF tubes as audio headphone amplifiers, where audio tubes like the 12AX7/ECC83 would be more appropriate. I also have no idea what the ICs are for in those units, as the tubes alone should suffice in this application just as they did in the 1950's-60's.
+Doug Browning Old surplus stuff. Personally, RF tubes always sound narrow.
Any chance we can measure heater voltages?
+Don Petrik All three tube types use 6.3 volt heaters.
6DJ8 - plate = 90V, grid = -1.3V, amplification factor = 33
6J9 - plate = 125V, grid = -1.0V, amplification factor = 57
6021 - plate = 100V, grid = -6.5V, amplification factor = 35
(all ratings per section)
+Doug Browning
"measure"
On paper is fine, what are we getting in the device for real? (measured heater current under load would be even better lol)
The ICs are mostly likely being used to generate clock signals to boost voltage from that battery through that 6800 uF capacitor. Think Dickson voltage doubler. That's likely how a 12 volt power supply or that rechargeable battery can achieve enough voltage to push a tube.
+Doug Browning A lot of the headphone amp designs I've seen tend to pass the signal through the tube, then use solid-state components to provide the final drive current to the relatively low impedance headphones. Most tubes have fairly high output impedance, unless you're using a cathode follower...
Great video as usual. There isn't a video on TH-cam that doesn't get trolled or hated on in some way, please just keep producing great content and ignore the uninformed masses that comment before they have even watched the whole thing...
"sorry about the breathing, i try to stop but it just keeps hapening"
Ur amazing. I needed that joke today.
Mate I think you should stop obsessing over the TH-cam comments
You can't make 100,000 people happy at once.
Most of us love your content and don't care about a silly mispronunciation or whatnot.
Sam Roberts eh, but but he wasn't seeking out the bad or anything, for that video the majority of comments really were cancerous
Comments seem to be blocked there now. That's probably a Very Good Thing to do, given the sample shown here.
While I agree, I actually found the teardown of the comments in this one very enjoyable. If he did that all the time it would get tiresome, but every once in a long while it's kind of nice.
I honestly really enjoyed him addressing the comments
@@RWBHere - Indeed.
I’m glad you brought up those comments. Some people take these things way too seriously. Keep doing what you’re doing and have a great time doing it. You make great videos, you’re having fun, and there’s lots of us who really enjoy viewing your creations. Thanks.
Great videos. I love these meta ones as well. Kudos to you for responding to all sorts of comments and not just ignoring them all as the rabble they may well be. TH-cam is a rough place to find respect, but you certainly deserve a helping or two for your approach.
LMAO. I love it. Tubes vs Valve. finger nails, touch vs don't touch. Priceless really priceless. You are always entertaining no matter what you talk about. Keep up the great work I really do appreciate all the hard work you put into these videos. -John
Dear Techmoan thank you for your great videos first of all. Addressing your questions - those tubes seem to be a part of the electric circuit and sound signal path. Circuit boards are double sided so you should not be confused with the fact that some of the pins are not connected on the one side. Whats a little bit disappointing is that the actual amplification is performed by an operational amplifiers and not the tubes, which are most likely connected as a cathode followers. Making a long story short - tubes are part of the signal chain but mostly for decoration and I would say marketing purposes (besides adding a little bit of distortion). You may find true full-tube devices with a higher price tag.
I know I am years too late here. But can I just applaud you for getting TH-cam Music Library music onto a cassette? Because that is absolutely fantastic.
Your videos are great. As a Canadian, your terminology sounds completely fine to me, including the word 'Tube'. I'm quite glad you skim over some of the technical discussions; I already know about matched impedence, what the mpeg-1 format is, and how CDs work; if not, I can always pause the video and spend sometime to look it up. To get a lesson on all that again in-video though would likely bore me, and sometimes I do skip chunks of your videos as a result. What I'm really here for is the same reason you enjoy making these videos -- playing with gadgets, technology, and all-around curiosity.
Audiophiles spend a ton of money and time trying to get the very best audio experience, even if it is often a placebo or a matter of taste. Inherently, those types of people are naturally anal retentive. I wouldn't let them get to you; your videos are great and I highly enjoy them.
i like your walkman cassette player.
thats a pretty nice vintage piece there.
Probably couldn't get his hands on a gramophone :P
Your dry sense of humour and your love for electrical oddities are the reasons that keep me coming back to your great channel. A regular viewer from Austria (maybe the only one from there)!
+Uli Mativ Nicht der Einzige nein ;-)
I like the cut of your jib. The polite sarcasm you employ is a perfect retort to the nonsense people spout in YT comments.
I enjoy watching your videos. I grew up with tubes, and I don't know anything about tube theory either. But, I did have a tube amplifier, a Fender twin reverb that constantly crackled and spit. I gave it to my brother in law who plugged it in and left it running for a week. Now it is fine. No criticisms, just enjoy what you do.
The first amp has two ne5532p chips. Those seem to be common on headphone amps of all types. I just built one using two of those with no tubes.The second one only has one. What I find interesting is the amp that you said sounded the best uses two of the NE5532P chips and has the cleanest board. The other two only use one chip.
Are they running as stereo one amp per channel or chained together ?
People often display a lack of civility on the Internet that they would never consider doing face-to-face.
+Milosz Ostrow Yes, quite indeed. My favorite ones are:
1. My generation sucks/living in the wrong era
2. General snobbism about music, genre etc. Closemindedness.
3. Being rude to people who give free tutorials that they don't provide the info fast enough because they speak.
4. Thinking there opinion is a rule, not a matter of preference or viewpoint.
5. The bad kind of trolls who just want to be rude and impolite.
6. The people who think everything needs a label and that everybody who doesn't know what it means is a donkey.
7. The ones that have good info but brought by very, very , very angry people because someone made a mistake (we're all human)
8. The grammer nazi's who like to exterminate the ones that can't grammer.
9. The ones that just talk nonense with meme's/hypes like the whole lizard thing.
10. The ones that ask for attention (DOES ANYONE LIKE THIS IN 2015)...
11. The people that think this has something to do with something that somewhere in their lives and tell a very long story what ends in a beg for attention.
I think I've got all that I think of....
+Jelte Derksen You've just described just about everyone on Facebook.
+Milosz Ostrow Of course they wouldn't do it face-to-face, they would be to afraid they would get there teeth kicked in, and rightly so.
+Jelte Derksen I was born in the wrong generation. Vinyl is the only way to really listen to music. Techmoan needs to talk faster. My opinion is fact. Fuck you. Everything needs labels. Actually you're not supposed to touch the tubes, goddammit Techmoan you piece of shit. *Grammar.
Hissssssssss. DAE LIKE TH-cam VIDEOS IN 2016? Once upon a time, some relevant stuff happened, so like my comment.
+Milosz Ostrow I have found the opposite to be true as well, really, just like anywhere there are dicks and there are decent people. Just on the internet the dicks might be decent people irl and the decent people might be dicks.
These people are " nit picking " I'm in detroit Michigan and have NEVER had any issue listening to, comprehending, or understand your videos! Keep up the great reviews!!
Ah.... But that is because Matt tends to monitor his demographics and chooses to use the word 'Choob' instead of *valve* accordingly.
It's because those who complain here are from Grosse Pointe
You can only please some of the people some of the time. Keep up the great work, please continue with the common speak and the accent is part of the charm in the video. Please do continue to have a great time with your hobby!
I'm an electrical engineer so maybe I can clear a few things up.
Low voltage isn't an issue here. See all the capacitors (labeled 16V)? (There is also an inductor.) Those are for a boost converter. Boost converters allow you to raise the voltage of DC with some tricks from AC electronics design.
The circuit boards in those amps were double sided. So even though only a few of the traces are visible from the bottom of the board, on the top layer there are connections to the other pins.
Please be careful with open tube amps because they utilize high voltages. The capacitors can retain the voltage after the device is powered down.
Thanks for all the great videos! This is my favorite TH-cam channel.
This man is an excellent communicator and thank you for sharing your knowledge with us my friend
I'm an audio engineer by profession. I have to laugh at these hi-fi guys. It's very much all snake oil and suffers from opinion riding over physics. Take a look in a professional recording studio. There's no gold plated connectors or £1200 IEC power cables there.. Keep up the great videos pal and thanks for your efforts..
+Andrew Kirkby I'm not a professional anything, but I quite like to do my own automotive work. 1) I find a sense of pride fixing my vehicle, 2) It's old and needs it often, so it saves me money, and 3) It's hard to find a garage that doesn't break more parts than it fixes. That being said... I hear people give me all kinds of vehicle advice, and much of it is snake oil as well. Telling me to put in additives and "HIGH POWER" spark plugs, telling me I should buy this or that to make the car work better. The truth is regular factory maintenance is what's important, no amount of snake oil will do a lick of difference.
+Jesse Crandle It's so true. Some things do alter your perception of sound but most listeners wouldn't know the difference and often those who say they had a better sounding system after an expensive upgrade have fallen short of the placebo effect to a degree.. I have a similar feeling about car repair. I do a lot of my own and tend to use manufacturer's recommended parts because that's what the vehicle was tested with and will likely get the performance I paid for when I bought it but adding expensive engine health additives etc will just burn the money you spent on them. A haynes guide to save the labour cost and a trip to a parts site like lings honda for instance is my robust solution... Unless the clutch goes.
Andrew Kirkby Best investment I've made in audio is a pair of Grado headphones. I had some SR80s, but after they broke I went to SR225s. The SR80s were a little lackluster in bass, so I went to the SR225s which has quite a bit more. A pleasant bonus was I could actually tell they were noticeably cleaner sounding, and the SR80s were already pretty impressive (coming from just sad Sony headphones that were 30 bucks, whatever you find online and in stores for less than $50).
+Andrew Kirkby I bet you guys don't even use an atomic, gps compensated clock for your 50hz/60hz AC line conditioner, do you?
Stop trolling him :p
6N11 and 6J9 are low noise amplifier tubes. The serials are Chinese variants in Europe the 6N11 is an EC88, and the 6J9 is a variant of a 12AU7 also a low noise amplifier. In my first valve amp, a CR Developments Kalypso 12AU7s were used as pre amplifier tubes, the power amplifier valves were EL84 - the big box(es) on valve amps are normally power transformers to drive the heaters in the valves. The Kalypso only produced 15watts total output which is why I used Triangle Comete loud spears with high impedance (I think they were around 96db) to get the best out of the amp. That was back in 1995. I was lucky to come across a pair of Quad valve amps from the 40's (which I had reconditioned) they used 500B power amp valves and were gorgeous. These were produced before the transistor was perfected in 1947. So yes Valves/tubes do work. They sound awesome though do 'colour' the sound, which I don't mind, I'm not that much of a purist, I like the warm tube sound.
Tube amps typically have an impedance transformer to step the impedance down from thousands of ohms at the plate of the tube to around 8 ohms for the speakers. At high power levels these transformers get large, heavy, and expensive to make.
As far as powering the tube, the current required is low, so these circuits can use a step-up ("buck") converter to raise the voltage from 12V. [Edit: confirmed; the tube is powered at 190V with a 6.3V heater]. The heater (a second circuit that powers the tube) is typically 6 or 12V, AC or DC, so good to go there. Finally, there is also the "Starved Plate" design where you don't run the tube at the highest voltage possible, but use a lower one. This can reduce noise and lead to extended tube life, although these small-signal tubes last a very long time (10,000 hours is typical). The Blue LEDs are somewhat bling-y, although the Chinese love an excess of bling, so to them it's probably minimally decorative rather than over the top as it might be seen in the West. There are diodes in the circuit, so the LED may simply be in place of a diode in the circuit that does not light up. In other words, possibly not useless as far as the circuit operation goes. I'm not suggesting these offer good, or even adequate performance; they are very cheaply made and little effort is made to increase or even address fidelity. Novelty items, but neat if you like that kind of thing.
Many years ago, I had an old consul stereo, she was cheap but the speakers were from an older consul and they were great quality. One day I was at an auction sale, and I purchased a Heathkit stereo receiver. She had dozens of tubes and I really wanted to know how it sounded, it must have been twenty years old back then. So I run the wires from the consul up to the amp, hooked up the record player which was a junker Gerard with changer, and played a few records. MAN what a difference! Those tubes changed an average consul stereo to almost BEING there! I loved it. It remained sitting atop that old consul stereo till my kids knocked the whole thing over roughhousing in the rec room in the basement where it lived.
I, like many others, saw your original value amp comparo and thought it was great. I loved the fact that you took the time to address many of the comments. I hope you don't let the negative comments bother you too much. Just do what you do best and let the trolls vent. I'm sure it's therapeutic and hopefully they feel better for it. And having lived in England for a number of years back in the 80's, I appreciate the more elegant and straight-forward way the Brits use language so please don't change that.
Thanks for your efforts. I appreciate it. Subscribed.
Your sense of humour cracks me up! You could be talking about a block of cheese and I'd still be entertained!
Keep doing what your doing and have a nice Christmas 😀
+GRUSS Newton Oh man... techmoan cheese reviews. I'd watch it, I love cheese...
Techmoan, I think you are doing great. I like it that you explain things for the layman who would be lost with all the technobabel. Your videos are very informative and entertaining. I've learned a lot from watching your channel. Keep up the great work.
The thing with fingerprints is that the acid in the grease etches the thin glass thus weakens it and it can then crack,
however, that is only valid on high power bulbs like Xenon headlight for cars where the rapid heatening may crack the glass where it's weakened.
For tubes it does not matter due to it's thick glass and slow warming up, the grease does effect and tends to remove the usual white printning though, as moist also will do.
+senohpi Acid in the finger oils? Now that's a new one to me. Would have to be some seriously acidic stuff to etch glass... :D
Now grease stains do have an effect on halogen bulbs and the like, but it's caused by the greasy spots heating up significantly more than the surrounding areas.
+MosoKaiser Only if he`s an alien )
While why fingerprints on bulbs is bad, your theory is incorrect. In halogen bulbs and Xenon bulbs, fingerprints prevent proper cooling of filaments and cause them to prematurely burn out. It has nothing to do with glass expanding or contracting, and more to do with heat dissipation. I've burned out bulbs on purpose as a demonstration, never had the glass fail as a result of fingerprints.
+Richard Stifle just to be clear, I understand you do agree that the fact remains fingerprints have no effect on the sort of low power diode and triode tubes used in home stereo systems.
Fingerprints do affect tubes that get incredibly hot, but not low temperature tubes found in these audio amplifiers and old TVs.
+senohpi You are right guys, i certainly mixed things up :)Regarding the halogen bulbs i suspect that the grease acts as a dark or reflective spot for a certain amount of the spectral energy that the filament emits, halogen have of course a very different distribution of the spectral energy than, for example the sun, has,thus gives insuffiecient cooling on that part where the grease is applied.Does it sound reasonable?.. i have to get a bunch of bulbs and do some experiments now :)
I prefer a tube/valve guitar amplifier. Never really considered one for just headphones. Thats audiophilia on a whole different level. Wow. Great video as always.
I love how much of this video was just addressing issues from people who didn't even pay attention to the first video.
your original video was perfect... let the haters hate. think about all the view you got from people that didn't comment? probably because they thought that (as i did) the video was great a straight to the point at my level. and guess what... i didn't comment on that video.
In each amplifier seems to have a NE5532 chip. A quick google search shows that this is an operational amplifier. op-amps are great for analog computing, and "amplifying" signals, but they in general are not designed to drive speakers and stuff. Generally the output is limited to a few tens of milliamps (mA) at most. They're probably serving as pre-amplifiers.
I would expect to see some boost converters inside all these to create at least a few hundred volts for the tubes, but I don't see any high voltage capacitors indicating that. However, all of them do seem to have switch mode converters, so maybe HV capacitors are present as SMD ceramics without values printed on them or something, IDK.
Although unlikely, these could be multilayer boards with traces literally inside the PCB, explaining why there are seem to be pins that aren't connected anywhere. It would also be that the tube amp does not require the functionality of every pin. Some tubes might have more grids than are necessary for instance, or possibly some pins are simply not used and dont connect to anything internally inside the tube. (engineers like to stick to universal standards for case styles.) Same is true for solid state electronics, sometimes devices just have a few pins where are simply labeled NC for Not Connected.
I am going to GUESS looking at the electronics that they do use the tubes as output stages, considering I do not see any discrete transistors (SMD, TO92, or otherwise) to drive the headphones near the output jacks. I don't think op amps are powerful enough to do that, not at high volume, anyway. I could be wrong though.
+Power Max Well there are some inductors present, and also a smaller 8 pin device that has had it's part no. scraped off. Maybe that's the boost circuit.
+AltoScroll And in the last one there literally is a ready-made boost converter sticking on the back there
+Power Max Convert this to English please, do they or don't they benefit from the "choobs"
+Bender Rodriquez it is English. If there are things you don't understand, Google it, and learn something new today.
TH-cam comment sections are almost always full of junk. But you said your original video even had an intelligent discussion, so that's great! You should probably heed your own advice from the end of the video and don't get too upset about all those comments. There will always be haters, stupid people, and those with a short attention span. No wonder the term "TL;DR" is pretty popular these days.
I know taking criticism is hard. But it's even harder if one also takes to heart stupidity or lack of attention that is not really criticism. Sometimes it's neither, but just a serious question that meant no harm.
Don't worry, your videos are great. They're on a professional level. I like every single one, even when they are about cameras that don't really interest me. They're still fun to watch.
Continue what you do. Me and your thumbs up/down ratio are telling you you're doing it right :) Thanks!
As an electrical & audio engineer. Your first video was more than adequate. As you stated this was for entertainment. And I was entertained.
Thank you for so much enjoyment! My teacher used to say that sarcasm would not bring me anywhere in life. This is probably not true but wherever I end up with my sarcasm I will be meeting you there. Drinks are on me. Looking forward to your next video!!
You are a legend.. Keep posting videos in the great British way!
It's not YouTUBE, it's YouValve you pillock! I kid, I kid. I think you take the comments sections too seriously.
THIS IS ENGLAND
that doesn't feel like i'm gonna be kicked in the butt and fall in a hole and die.... sounds more like an invitation to drink tea
that's gold
It's youchoob
I do like the use of the word pillock :D
While I can't say for sure without reading the markings on the chips, all three units seem like hybrid designs. The valves are powered and seem to be used as a pre-amp stage while there are digital op-amps for actually increasing the audio signal. This would make sense because the valves would need more power than digital circuitry to increase the audio signal than the op-amps would. This is done mainly because as you up the power to get the valves working you would need better rated components to cope with that plus extra heat generated within the units. A hybrid design in this case becomes far less costly than a pure valve one.
A hybrid is also more efficient, because using tubes as power amplifiers requires a hefty (and not at all safe to poking) B+ voltage. The beefiest caps I saw in the teardowns were rated at 50V, so the B+ rail would have to be less than that and audio tubes really want a few HUNDRED volts to really cook. If they're just being used as lower power pre-amplification, then you don't need nearly so much voltage -- but it also defeats the purpose of using tubes because they're not being driven anywhere near saturation. Everything that is not defective sounds about the same in its linear range. It's what they do when pushed out of the linear range that makes all the difference. In other words -- the tubes work, but they aren't doing anything to the sound because they have to be pushed to do that and these circuits simply can't.
Personally I aim for reference everything. No EQ or tone controls, speakers or headphones that are as flat and uncolored as possible, no surround effects or enhancements, etc. It does mean my setup is not at all "forgiving". Bad recordings sound like bad recordings. (In such cases, I may cheat and use some EQ.) But the way I see it, how can I go wrong trying to match actual studio gear as closely as possible? Why shouldn't I hear what the engineer intended for me to hear?
I also engineer my own music on the same system: a 160W solid-state amplifier which I don't push even halfway there, a pair of Tannoy SRM12B monitors, and modified Sony MDR-V600 headphones (modified to eliminate their "bass boost" and make them behave more like the MDR-V6).
I do have a consumer grade entertainment setup as well, and I listen back to my music to make sure it doesn't get totally destroyed, but honestly it's not my lookout if someone pushes my tunes through shite hardware.
@@mal2ksc Lots here; but a couple of key things: 1. it's unlikely your listening space is close to the acoustic surroundings of the studio control room where the music was mixed. 2. Generally speaking your listening to the output of a mastering engineer, not the mix engineer and 3. We all have different tastes, some like more bass, others like more highs. either way, what you're striving for is a preference, one that the mastering engineer had but not necessarily yours. Give two mastering engineers the same stems and you'll end up with two different outcomes, neither are right or wrong, but different they will be.... Still sure your setup is optimal...?
Techmoan, here's a pseudo-latin phrase for you: Illegitimi non carborundum. That is supposed to mean: Don't let the bastards grind you down. Just keep doing your thing. You're are doing a good job and you are being honest and that is refreshing.
I'm glad you went back and called out everybody that didn't pay attention and all the snobs. Love your content. I have no problems with anything youve done or will do. Keep it all up.
The circuits look legit from a first look.
The NE5532 chips look to be used as pre-amps before the valves, all the electronics seem to be fully analog from what is shown making a dummy delay circuit unlikely, the small surface mounted chips look like part of the DC-DC step up converters as valves generally need a high voltage to operate. There are exceptions to this of course.
I agree hobbies are for enjoying, tinkering with electronics and computers is very much fun for me. Good to see you don't worry about the Ellettest numptees, I tend to find such individuals amusing.
You have the patience of a Saint and some people need to get a live...
My mom says that patience is the virtue of saints...
As a guitar player, the section with all the "Anti-tube" excuse me "valve" people, really made me laugh.
I'm actually interested in these specifically for practicing guitar when everyone else is sleeping. It looks like a neat solution.
@Philip Turner - I'm a guitarist too... And always use my trusty valve amps. But being thermionic valve trained (rado comms) furnishes me with a modicum of technical understanding.
Technically, it is all down to 'odd harmonics' a factor of thermionic valve characteristics. The 'clipping' (distortion) created by semiconductors is very 'harsh' - or square-wave as a function of the 'even' harmonics of the component in use - transistors. Whereas, thermionics clip at the 'odd' harmonics, which creates a much *rounder* clipping characteristic. Simply put - valves/tubes/bottles distort across a broader bandwidth, where the clipping is not so square waved, so they sound less harsh. An important consideration when using Hi-Z reluctors (magnetic pickups) with a broad frequency response and high amplitude. This same characteristic, also explains why valve HiFi amps sound generally more pleasing (warmer) to the ear than their semiconductor cousins.
Of course, the new (ish) development of 'amp modelling' is an attempt to emulate those valve characteristics, with varying degrees of accuracy and success. But that signal is still going through a semiconductor or hybrid signal chain, where that even harmonic distortion is ever present. Transistors just can't cut the mustard when it comes to playing a guitar through an amplifier, certainly not a high power levels.
Any thermionic device - such as a valve radio, radiogram/record player, or tape recorder can be used as a really decent valve practice amp. Simply hook up your guitar to the Hi-Z input (or if your guitar is active, use the line input) and you're good to go.
@@acerbicgeoff7821 It's not a neat solution cos they're not actually valve amps. The valves don't amplify. Signal passes through them, but in a way that's basically cosmetic. They don't have the "valve sound" guitarists like.
For headphones, is a little transistor amp so bad? If people perform with them, they should be good enough for practice right? And any practice amp, any two amps at all, are gonna sound different. So does it matter to get a valve one?
Finally, don't guitar amps usually have headphone sockets?
@@greenaum I understand your point, and yes they do, but if I want to go out in the backyard, I don't generally like dragging my amp out and laying down a drop cord just so I can drink and chain smoke out of the way of the family. You are right it's basically cosmetic, and my current solution of a headphone amp that literally runs on batteries and stays connected to the guitar is far more portable, but others might like the little gadgets too. It's all preference
@@acerbicgeoff7821 No I mean in THESE amps the valves really ARE cosmetic! They're NOT VALVE AMPS!
I can't remember exactly from the teardown, but basically signal passes from one plate to the other, in these. In a normal valve amp, the valve is an amplifying element, and in doing this, the valve's nature affects the sound.
These are purely silicon op-amp amps! They're a ripoff, is the point. They won't sound like what you're expecting.
A little portable valve amp might be nice. It'd probably cos you though. You'd need a few PP3s to power it, the simplest way. Whatever. It could be done. But not as cheaply as in these, and certainly not as shitly!
They're a ripoff mate! Purely cosmetic as in visual cosmetics! The valve is in-circuit but not actually modifying the sound signal, AT ALL!
Came in for the follow up, was immediately reeled in by the sharp, dry wit of the opening few minutes. Love your videos!
Techmoan: Ignore the elitists who have big egos! Yes, they are correct in mentioning some of the nomenclatures you mentioned in this video package, BUT it's your video, do as you wish...those who criticize have nothing better to do than watching and being snobs. The work you do with your writing, camera angles, editing, narration, lighting as well as subject matter is "TOP NOTCH"! Please keep up the great work! And remember, as I'm sure you alread know, you can't please everybody, but you should please yourself.
Those blue LEDs were definitelly loss of ａｅｓｔｈｅｔｉｃｓ
"it's later than you think" I like that, thanks.
Don't feel bad, it's not just you, or even "HiFi people", it's the internet in general.
I remember a fairly recent event where quite a high profile TH-camr had the audacity to buy a goldfish for the first time, and of course vlog the whole thing. She was utterly eviscerated by a gang of internet thugs from the self-declared "fish community". It drove her to tears and made her feel obligated to post a sickening "apology video", where she prostrated herself before the world just because she committed the heinous crime of putting something most cultures consider to be little more than a snack into "the wrong sort of tank".
But yeah, HiFi nutjobs are just as obnoxious. They're just not particularly unique.
I don`t care how you talk, your videos are great, that's why I'm a patreon .
I know this is an old video now, but do people not realize that some people are also hard of hearing??? I’ve been using headphone amplifiers for years. There’s another reason for you. Thank you for calling out these mouth breathers. And not censoring their names. 👍
That "The NTNON Hi-Fi shop sketch" was halerious!!!!
Ive been watching your shows for years now and I only managed to see this one now (thats COVID-19 lockdown for you). TH-cam comments, for some strange reason, can be particularly nasty and i've seen some of the unkindest things mentioned in the posts. I have always felt a bit of pity for the youtube creators putting the effort they do into these videos (and theres a lot that goes into it!) only for some 12 year old to tear it apart.
Dude your shows are great! Never change them :)
Oh and when it comes to audiophiles your'e opening a pandora's box. As a sound engineer I take a pretty pragmatic approach to audio, there are no rules to all this, even the noisiest pre-amp serves its purpose somewhere. Life is just too short to over think this all :D
Send them to big clive, he'll figure it out
I'm late but yes!
Those things would be great for HV switchemathinging.
This is also my thought.
i have TONS of respect to you! i generally like people from england but the fact you just went half the video length to breake down these stupid comments is awesome!
i've never seen someone doing that and u have tons respect to us as i see 🙄
keep doing what you love
You put sooo much effort to tear things down to ignorants, less intelligent people. I respect that, i really do! Many thanks for all the enjoyment that you are giving to us through all those years, precious moments all over you well-constructed videos.
"Don't turn it on, TAKE IT APART!" Someone here likes to watch EEVblog.
as a fellow brit with a sense of humor unlike some of our cousins this was a great tongue in cheek vid well done you, made me laugh anyway.
"Not The Nine O'Clock News - HiFi Shop" sketch: PRICELESS :)))
My brother is a guitar player. He swears by tube amps. He said the sound is "warmer and more alive". When I was in grade school, I had a nice tube radio in my room. The back was missing, but that was fine. I used to turn it around so you could see the gentle glow when the lights were out.
Don't let these passionate nerds get to you. They will pick apart every little thing. That is why they don't socialize very well. Keep up the good work!
Thanks for uploading this video to YouChoob!
I really enjoy these comment answering videos...
Two countries divided by a common language
You really inspired me to start experimenting more with my hifi setup. Before i watched you i would never put a cheap Chinese thing like that in my hifi and now i did. I bough one of those cheap 6j1 kits on aliexpress, i replaced the tubes with better ones and put some brand name capacitors in it. I use it with my cd player that i always thought sounded too bright, now it sounds a bit richer.
Techmoan, thank you for your excellent work, it is look like the whole TV team is behind your work.