THE major difference of tube output stages (vs transistor output stages), is that the output 'follows' the impedance curve of the speaker system! This results in 'dips' in the frequency response where there are impedance-dips!
Loved the video. Recently started down the tube amp path and really enjoying what I'm listening to. Wouldn't it be great to see the reviews of all products, the good, the bad and the ugly!
Great video post! Also nice that you know Stephe from Skunkie Designs. I LOVE her channel and it is first and foremost on my search list. What caught my attention with her is that she has that Audio Analyzer Suite and can fully test the amplifiers she builds or checks out. She was one of the first to really thoroughly get into an amplifier and describe it from top to bottom. While I do have prior tube knowledge myself, I found that I learned a LOT more just by viewing posts on her page. In fact it was through her that I had seen links to your channel. It was your Magnavox SE EL84 amp and how you compared it to a push pull 6V6 amp that got me going. It really gave me a good idea of what a SE amp can sound like. Now, out of the amps you mentioned, I had already looked at what Stephe had to say about them, but the best part was that she found ways to improve the flaws the amps had. While I was tempted to get a Resong amp and mod it, I just figured it was better to stick with one of her designs, which was originally a Kegger design. I would be far better off with one of those. Then she has the Color Pre-Amp too, that I am interested in. I been poking my head in more often here too as you do have really good posts. Further, you have gone through a lot of classic pieces and know what is good (and not) there. Skylabs Audio is another site I frequent, as that fellow has an audio repair shop and he fixes (and sells) vintage equipment. I enjoy his page because there is a parallel interest. I used to fix audio equipment myself, but I mostly dealt with commercial gear and guitar amplifiers, so that is where I got most of my tube knowledge from. But dealing with tube equipment for guitars is quite different from hi-fi, but I did dabble with the latter myself and do want to get into it. I am going to build Stephe's 12AX7 / EL34 SE amp soon, I am just getting all the parts together for it. Oh! And for companies that threaten for honest negative reviews (I.E. Tekton), I would tell them to stick it where the sun don't shine! Anyway, keep up the great work! Can't wait for the next post!
I don't actually know Stephe. I just really like her content. I think I first saw her posts on Audiokarma.org, so when I found her on TH-cam, I figured she was the real deal. I was a minute away from ordering the analysis stuff she uses, but then I saw that the freeware only runs on PC; I'll get there, just not today! 😐🤣
@@Lancaster_Hi-Fi I have talked to her on a few occasions, not live, mind you, but here on YT. Yeah, I was amazed at how she gets VERY detailed with her testing and explaining. I don't even see 'pro' testers and reviewers get as detailed. I think I came across her channel when I was looking into tube based phono pre-amps and she built a clone of the EAR 834 amplifier and had very positive reviews of it. So I stuck around to check out her other stuff. I was very much turned on to the new 12AX7 / EL34 amplifier she created and I intend to build one myself.
I liked this technical stuff as well as your presentation. I usually don't comment unless I have something to say but you encouraged comment so there you have it. That was good.
Yes, thanks! The script was already about half written, but your comment was part of what got me to take it further (and rewatch a ton of Skunkie's videos). Unfortunately, makers don't publish service manuals, schematics, or performance data anymore, so I could only comment on the data in the review that, interestingly, the TubeCube people linked on their site.
U got a subscribe today!! I'm not a Tube Amp Guy. Tube Preamp to Solid State is more of my lane.( Feeling only the proper harmonics need amplification) My working theory is there is no Analog or Digital because both methods actually rely on electron flow also Tape or Vinyl can only transport as fast as the motor will allow.( Think about that). Thanks again for pointing out how Audiophiles pay good money for bad things.
I used to visit HiFi forums on tube audio equipment, and would often see posts from 'golden eared' audiophiles about 'tube rolling'. They would suggest changing this tube or that tube to a different one. When I mentioned that they couldn't just swap tubes without changing the plate or cathode resistors, I just got a storm of criticism about 'measure with your ears', not test equipment. These are people that learned everything they know from the internet {good idea), but had no knowledge about electronics. I finally gave up on these forums, and quit participating in them. These people are the kind that swear they can hear the effects of the color of the insulation on the wiring used in the amp, but are apparently oblivious to the gross distortion produced by a poorly designed amp or preamp. PT Barnum was right. "There's a sucker born every minute".
Another good one. A lot to unpack. Might using a vintage tube pre-amp open up a can of magic on a modern push-pull non-integrated amp with KT 88 output tubes?
I'm currently in the planning stages of a single ended pentode design starting with a blank sheet of paper. I will be utilizing any modern-day electronics to achieve the optimum utilization of the output stage. I wondered what the great designers of the 50s would have done in their designs had they not have their current day electronic limitations. I also think that traditional designs are great for that day and if you're restoring a vintage peace, then you should adhere to the original design, to maintain the nostalgic sound. My goal is to see what you can get out of a pentode if you minimize the compromises.
Not only distortion is a desirable quality for guitar players, but also _dynamic touch sensitivity._ That is to say, when playing softly the signal is less distorted, and when played aggressively becomes more distorted. Solid state circuits cannot duplicate this, although they have come pretty close. Good video. Cheers!
Question. Do you do work for others? I’ve got a working Dynaco ST70. It could use a checkup from a skilled tech though. I’m fairly local to you I think. If not, is there anyone you’d recommend in the Portland area?
I do. I'm in Corvallis. If you're on FB, look for Stephen Lancaster. Also, you should be able to get my Gmail through my channel page. If those fail, @geomorphdog on IG.
@@Lancaster_Hi-Fi great, just followed you on IG. I had emailed you previously. It might have gone into your spam folder. I’ll send you a DM on Instagram.
I'm currently in the process of building an OTL (Output Transformerless) Headphone Amplifier that uses three 9-pin Svetlana 6N1P dual triode tubes, it is a DC coupled amp, meaning that one half of one 6N1P tube has the anode directly coupled to the grid of one half of another 6N1P tube that's connected up in a configuration known as a White Cathode-Follower output stage, the output is DC isolated from the headphones by a 470uF/450V DC electrolytic can cap, the design I'm building can drive headphones with impedances down to about 32 Ohms, It runs off a power supply that produces 348V DC @ 100mA, and 6.3V DC @ 2A.
Why? I ask because as a design engineer, I embark on a project to get better performance than is either available or affordable. A transistor amp, especially for low power and impedance can be orders of magnitude better than any tube amplifier. It just doesn’t make sense to go through all the hoops you mention to end up with an inferior solution.
Better or worse is a matter of taste. In terms of total harmonic distortion, transistor amps typically do have orders of magnitude less than tube amps, but some distortion is tolerable or even desirable. Triodes, like the 6N1P, produce predominantly 2nd harmonic distortion, which generally sounds pleasant, at least in small doses. Triode amplification, then, has an advantage over BJTs. You could then argue that op-amp voltage followers or BJT emitter followers would make better output buffers, but if cathode followers are a good enough solution, then they might be preferable simply by being the simpler solution. For example, if I want to use op-amps, then I need +/-18V supplies, which require additional devices.
@@Lancaster_Hi-Fi Better is a mathematical expression, just like “>” or greater than. I know fake news is all the rage these days, but lower distortion is objectively better, no matter what semantic games rock your world. If you prefer adding the non-linear transfer function of a tube or transistor class A amp, that is a matter of taste. However, the resulting sound IS worse, quantitatively and objectively so. I’ve watched countless people swear by the superiority of the 1-2% THD of their tube amplifiers, and yes, that high distortion layered atop the original perfection of the live performance is actually their preference; their ‘taste.’ Musicians beg to differ, glowing orange shiny things or not.
I most likely introduced some flaws in a good design by Bruce Rozenblit. I substituted 6n2p for 12AX7A input stage and 6n6p for 12AU7A cathode coupled phase splitters without adjusting the operating points. I just hoped for the best. It sounds fine to me, but who knows without testing which is beyond my capabilities. Guilty as charged. :)
I feel like "access journalism" exists in the reviewing field. If I were to give an honest negative review about a new DAC- I could expect other manufacturers to skip me over when it came time to pre-release stuff. Pretty much if your favorite reviewers releases a "review" on the same day as five others, that means they are all *on good terms* with that company and the industry FWIW
My journey with tubes started about 1963 with a Mullard 3-3 as a young teenager. It was followed by 5-10's, 5-20's as a 20 year old. The Mullard passive preamp was terrible!. Heard some enthusiast's Williamsons with Baxandall preamp. My Williamsons and Baxnandall preamp lasted for over 35 years. Anyway my current tube amps use KT88's and are sitting on the shelf gathering cobwebs. Class A Hiraga's and a preamp with OPA2134s and NE5532s quite frankly sound better, are more reliable and far less costly. Its been quite a journey.
It is not an opinion ...........IT IS A FACT ! Fully agree with you .........and many get indeed rave reviews by those who do not have the knowledge of tubes ..........but they think they have .
Totally. Gotta streamline production. It's ridiculous how much more time it takes to look at the camera while talking and edit out the bits where I'm reading the screen. (And we're talking a laptop sitting on top of an overturned laundry basket on top of my nightstand so the screen would at least be at the same level as the camera.) So yeah, you got me.
Tube amps are the single most over glorified and hyped thing on the market. Everything from delusional types that think a SET is a perfect match to any speaker because...tube magic. And there are never flaws, just intentional "flavors" of smooth and natural. Where people see something like a dark voice tube headphone amp as a holy grail, it sounds like horrible incompetence to me.
Im buying a 300B SET Amp !!! I broke down and decided to get the Willsenton 300B! Im getting it brand new ! Will report back once it arrives. Thanks for todays breakdown!! 🕺
Soooo refreshing...These hard-won insights are priceless...Keep up the good work!
Thanks!
THE major difference of tube output stages (vs transistor output stages), is that the output 'follows' the impedance curve of the speaker system! This results in 'dips' in the frequency response where there are impedance-dips!
Loved the video. Recently started down the tube amp path and really enjoying what I'm listening to. Wouldn't it be great to see the reviews of all products, the good, the bad and the ugly!
Yes!
Great video post! Also nice that you know Stephe from Skunkie Designs. I LOVE her channel and it is first and foremost on my search list. What caught my attention with her is that she has that Audio Analyzer Suite and can fully test the amplifiers she builds or checks out. She was one of the first to really thoroughly get into an amplifier and describe it from top to bottom. While I do have prior tube knowledge myself, I found that I learned a LOT more just by viewing posts on her page. In fact it was through her that I had seen links to your channel. It was your Magnavox SE EL84 amp and how you compared it to a push pull 6V6 amp that got me going. It really gave me a good idea of what a SE amp can sound like. Now, out of the amps you mentioned, I had already looked at what Stephe had to say about them, but the best part was that she found ways to improve the flaws the amps had. While I was tempted to get a Resong amp and mod it, I just figured it was better to stick with one of her designs, which was originally a Kegger design. I would be far better off with one of those. Then she has the Color Pre-Amp too, that I am interested in. I been poking my head in more often here too as you do have really good posts. Further, you have gone through a lot of classic pieces and know what is good (and not) there. Skylabs Audio is another site I frequent, as that fellow has an audio repair shop and he fixes (and sells) vintage equipment. I enjoy his page because there is a parallel interest. I used to fix audio equipment myself, but I mostly dealt with commercial gear and guitar amplifiers, so that is where I got most of my tube knowledge from. But dealing with tube equipment for guitars is quite different from hi-fi, but I did dabble with the latter myself and do want to get into it. I am going to build Stephe's 12AX7 / EL34 SE amp soon, I am just getting all the parts together for it. Oh! And for companies that threaten for honest negative reviews (I.E. Tekton), I would tell them to stick it where the sun don't shine! Anyway, keep up the great work! Can't wait for the next post!
I don't actually know Stephe. I just really like her content. I think I first saw her posts on Audiokarma.org, so when I found her on TH-cam, I figured she was the real deal. I was a minute away from ordering the analysis stuff she uses, but then I saw that the freeware only runs on PC; I'll get there, just not today! 😐🤣
And, yeah, I'm a big fan of Skylab, too.
@@Lancaster_Hi-Fi I kind of figured you were familiar with him :).
@@Lancaster_Hi-Fi I have talked to her on a few occasions, not live, mind you, but here on YT. Yeah, I was amazed at how she gets VERY detailed with her testing and explaining. I don't even see 'pro' testers and reviewers get as detailed. I think I came across her channel when I was looking into tube based phono pre-amps and she built a clone of the EAR 834 amplifier and had very positive reviews of it. So I stuck around to check out her other stuff. I was very much turned on to the new 12AX7 / EL34 amplifier she created and I intend to build one myself.
@@Lancaster_Hi-Fi Not sure if you saw his last video this week, of the tour of his shop. As he always says, "It's a fun one".
Thanks for the shout out and nice video :)
I liked this technical stuff as well as your presentation. I usually don't comment unless I have something to say but you encouraged comment so there you have it. That was good.
Great information. And in an entertaining but balanced way.
Cue the legal trouble! Seriously, thanks for a nice rundown of tube amp circuit considerations. Cheers!
Great video! Glad my inquiry about the tubecube 7 contributed to the conversation if only a little, lol.
Yes, thanks! The script was already about half written, but your comment was part of what got me to take it further (and rewatch a ton of Skunkie's videos). Unfortunately, makers don't publish service manuals, schematics, or performance data anymore, so I could only comment on the data in the review that, interestingly, the TubeCube people linked on their site.
U got a subscribe today!! I'm not a Tube Amp Guy.
Tube Preamp to Solid State is more of my lane.( Feeling only the proper harmonics need amplification)
My working theory is there is no Analog or Digital because both methods actually rely on electron flow also Tape or Vinyl can only transport as fast as the motor will allow.( Think about that).
Thanks again for pointing out how Audiophiles pay good money for bad things.
I used to visit HiFi forums on tube audio equipment, and would often see posts from 'golden eared' audiophiles about 'tube rolling'. They would suggest changing this tube or that tube to a different one. When I mentioned that they couldn't just swap tubes without changing the plate or cathode resistors, I just got a storm of criticism about 'measure with your ears', not test equipment. These are people that learned everything they know from the internet {good idea), but had no knowledge about electronics. I finally gave up on these forums, and quit participating in them. These people are the kind that swear they can hear the effects of the color of the insulation on the wiring used in the amp, but are apparently oblivious to the gross distortion produced by a poorly designed amp or preamp. PT Barnum was right. "There's a sucker born every minute".
Another good one. A lot to unpack. Might using a vintage tube pre-amp open up a can of magic on a modern push-pull non-integrated amp with KT 88 output tubes?
Well, sure! Of course, those KT88's will provide a lot of magic on their own!
I'm currently in the planning stages of a single ended pentode design starting with a blank sheet of paper. I will be utilizing any modern-day electronics to achieve the optimum utilization of the output stage. I wondered what the great designers of the 50s would have done in their designs had they not have their current day electronic limitations. I also think that traditional designs are great for that day and if you're restoring a vintage peace, then you should adhere to the original design, to maintain the nostalgic sound. My goal is to see what you can get out of a pentode if you minimize the compromises.
Not only distortion is a desirable quality for guitar players, but also _dynamic touch sensitivity._
That is to say, when playing softly the signal is less distorted, and when played aggressively becomes more distorted.
Solid state circuits cannot duplicate this, although they have come pretty close.
Good video.
Cheers!
Yes, but I decided to leave that out. 😁
Is a set of KT88s push/pull enough to power Magnepans? Small ones?
I would think so, but I don't have any experience with Magnepans, or with KT88s. I do have a couple of Dynaco Mark III's in the queue, though.
Great video! I believe i’ve heard Stephe pronounce her name ‘Steffee’ somewhere.
Ah! Thanks! She doesn't say her own name often. At least I was close, I guess. 😕🤣
@@Lancaster_Hi-Fi Yeah either is fine :) Nice video.
Thanks!
Question. Do you do work for others? I’ve got a working Dynaco ST70. It could use a checkup from a skilled tech though. I’m fairly local to you I think.
If not, is there anyone you’d recommend in the Portland area?
I do. I'm in Corvallis. If you're on FB, look for Stephen Lancaster. Also, you should be able to get my Gmail through my channel page. If those fail, @geomorphdog on IG.
@@Lancaster_Hi-Fi great, just followed you on IG. I had emailed you previously. It might have gone into your spam folder. I’ll send you a DM on Instagram.
I'm currently in the process of building an OTL (Output Transformerless) Headphone Amplifier that uses three 9-pin Svetlana 6N1P dual triode tubes, it is a DC coupled amp, meaning that one half of one 6N1P tube has the anode directly coupled to the grid of one half of another 6N1P tube that's connected up in a configuration known as a White Cathode-Follower output stage, the output is DC isolated from the headphones by a 470uF/450V DC electrolytic can cap, the design I'm building can drive headphones with impedances down to about 32 Ohms, It runs off a power supply that produces 348V DC @ 100mA, and 6.3V DC @ 2A.
Why? I ask because as a design engineer, I embark on a project to get better performance than is either available or affordable. A transistor amp, especially for low power and impedance can be orders of magnitude better than any tube amplifier. It just doesn’t make sense to go through all the hoops you mention to end up with an inferior solution.
Better or worse is a matter of taste. In terms of total harmonic distortion, transistor amps typically do have orders of magnitude less than tube amps, but some distortion is tolerable or even desirable. Triodes, like the 6N1P, produce predominantly 2nd harmonic distortion, which generally sounds pleasant, at least in small doses. Triode amplification, then, has an advantage over BJTs. You could then argue that op-amp voltage followers or BJT emitter followers would make better output buffers, but if cathode followers are a good enough solution, then they might be preferable simply by being the simpler solution. For example, if I want to use op-amps, then I need +/-18V supplies, which require additional devices.
@@Lancaster_Hi-Fi Better is a mathematical expression, just like “>” or greater than. I know fake news is all the rage these days, but lower distortion is objectively better, no matter what semantic games rock your world. If you prefer adding the non-linear transfer function of a tube or transistor class A amp, that is a matter of taste. However, the resulting sound IS worse, quantitatively and objectively so.
I’ve watched countless people swear by the superiority of the 1-2% THD of their tube amplifiers, and yes, that high distortion layered atop the original perfection of the live performance is actually their preference; their ‘taste.’ Musicians beg to differ, glowing orange shiny things or not.
I most likely introduced some flaws in a good design by Bruce Rozenblit. I substituted 6n2p for 12AX7A input stage and 6n6p for 12AU7A cathode coupled phase splitters without adjusting the operating points. I just hoped for the best. It sounds fine to me, but who knows without testing which is beyond my capabilities. Guilty as charged. :)
At least you have self knowledge. 😁🤣
I feel like "access journalism" exists in the reviewing field. If I were to give an honest negative review about a new DAC- I could expect other manufacturers to skip me over when it came time to pre-release stuff. Pretty much if your favorite reviewers releases a "review" on the same day as five others, that means they are all *on good terms* with that company and the industry FWIW
Well, that's part of what I didn't want to say in the video, but yeah, exactly!
That's most of ',em.
My journey with tubes started about 1963 with a Mullard 3-3 as a young teenager. It was followed by 5-10's, 5-20's as a 20 year old. The Mullard passive preamp was terrible!. Heard some enthusiast's Williamsons with Baxandall preamp. My Williamsons and Baxnandall preamp lasted for over 35 years. Anyway my current tube amps use KT88's and are sitting on the shelf gathering cobwebs. Class A Hiraga's and a preamp with OPA2134s and NE5532s quite frankly sound better, are more reliable and far less costly. Its been quite a journey.
Wait, this isn't about Ray Samuels Audio?
Er, I'm not familiar. Recommended, or ...?
@@Lancaster_Hi-Fi OML no.
Well, now I'm going to have to check out his channel for sure! 🤣
It is not an opinion ...........IT IS A FACT !
Fully agree with you .........and many get indeed rave reviews by those who do not have the knowledge of tubes ..........but they think they have .
Yeah, but with some people being lawyer-happy, I just figured I'd throw in a few "I think"'s and "in my opinion"'s. 🤣😐
You're reading lol
Totally. Gotta streamline production. It's ridiculous how much more time it takes to look at the camera while talking and edit out the bits where I'm reading the screen. (And we're talking a laptop sitting on top of an overturned laundry basket on top of my nightstand so the screen would at least be at the same level as the camera.) So yeah, you got me.
@@Lancaster_Hi-FiI prefer the video like this. Without all the cuts. I thought maybe the cuts were a stylistic thing.
Tube amps are the single most over glorified and hyped thing on the market.
Everything from delusional types that think a SET is a perfect match to any speaker because...tube magic.
And there are never flaws, just intentional "flavors" of smooth and natural.
Where people see something like a dark voice tube headphone amp as a holy grail, it sounds like horrible incompetence to me.
Chinese junk tubes are overrated. A thoughtfully designed SET or PP with quality parts certainly has it's merits in a well matched system.
Im buying a 300B SET Amp !!! I broke down and decided to get the Willsenton 300B!
Im getting it brand new ! Will report back once it arrives. Thanks for todays breakdown!! 🕺
Check out Skunky Designs review of it. It has a design flaw or two I believe.
@@hanksta34 I already warned him not to buy one, looks like he did anyway.