LUXMAN Preamplifier Repair - The LUXKIT A3300 Preamp
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- Burn't up Luxman! Let's find the problem and fix this beautiful older preamplifier. To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: / mrcarlsonslab
#restoration #electronics #repairing
To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: www.patreon.com/MrCarlsonsLab
Your repair video educational
Mr Carlson, no idea where to start other than I like your teachings , makes my 85-89 Physics, electronics teachings coupled with tech drawing to shame at Deyes High School, Maghull ,Liverpool.,Merseyside ,L316DE (post code / zip code Canada )England.
Anyway , I'm in Republic of Ireland ,South Coast , my two kids also 11, and 13 , both gamers , however we like basic electronics ....
Any advice , moreso for me tbh
Why the F didn't they teach or even now teach like you do ?
Ooops I know why , keep us down 👇
Mr Nicholas Hampson
N
This video really showcases Mr. Carlson's attention to detail. One of (if not the) most knowledgeable electronics guru's on TH-cam.
Talents...well..he has a couple of rivals for that honour...over here in Britain near Birmingham...we have MenditMark channel...he has about as many diagnostic machines as Mr Carlson...and knows how to use them too...also an ex pat from here now lives in Canary Islands and has a channel Learn Electronics and is a teacher to subscribers...not quite as many diagnostics but it's quality over quantity as they say
Paul "Sherlock" Carlson practising post-mortem criminalistics and inspecting fingerprints inside a power supply. 🙂
Most entertaining and thanks for showing us.
We need to clone your brain Mr. Carlson. AI can't hold a candle to your knowledge.
AI has not reached this amount of intelligence yet.
@@dougtaylor7724 LOL!
If I may add, you have a radio voice that can easily zen us throughout a troubleshooting process.
@dougtaylor7724
That's done purposely to not take over the military where most A.I. is utilized.
The concept of actively troubleshooting electronics has nothing whatsoever to do with AI but it can help you understand how a circuit works.
Really liked your repair work on this stereo preamp. Good job explaining the circuit and what parts was needing replaced. Thank you Mr Carlson.
You are welcome!
You are responsible for my interest in electronics. Thanks for having turned your house in a movie set and allowing me the best seat for the show. Asking the right questions is the better part of learning. I appreciate the drive you bring in my experience. Cheers
As a long time viewer I've long since realized you're carefully selecting what you think would be the most educational for each video. That said I'm surprised you didn't express regret that whomever destroyed those screws didn't use a proper set of JIS screwdrivers which would have prevented that. It's important to remember that any gear from Japan will use JIS spec screws and that standard Phillips bits will cam out and strip those.
I've been using a curve tracer since the early 1970s during my Navy career. Back then, it was just the basic components cobbled together, driven by an audio generator and displayed on an oscilloscope via the X and Y axes. One of the best tools available.
Yeah, they used to call them an octopus, if memory serves me right. I later used a Huntron Tracker and it was very useful as well.
Yes I was introduced to the curve tracer in the Navy in the 70s we called it the octopus. It was a staple on my bench until I retired a few years ago.
The company I work for PTS electronics also made one to be attached to your o scope.
Ive never used a curve tracer. If a transistor is bad an ohmeter will reveal it . I suppose its good for trouble shooting, which I dont do much of. Is this usefull with the transistor in the circuit? In that case not having to take the transistor out to check it helps.
@@kevinhamming4514 The curve tracer can be used when components are in circuit. I get better results with them out. The curve tracer will show you leaky diodes and transistors that an ohm meter won’t. It will also show a leaky electrolytic cap.
I have been following your content for over 4 years. I am never disappointed with the level of detail you go through to not only explain the basics but also the meticulous way you troubleshoot and rectify (yes pun intended here) the big and small problems. You go above and beyond to even uncover mistakes in factory manuals. This one is even more interesting where you casually opened the PS to discover potential deal breakers if left to itself. Your passion for what you do is just out of the charts and your desire to share this with the masses is so beneficial to both casual enthusiasts but even some pros who do not take the trouble explaining what, why or how they fix things
Agree... I found Mr. Carlson's lab several years ago because I had no idea what & how a capacitor worked. I since have followed his videos for my learning and have over time taken lot's of notes. I often refer his channel to others that I come across on a couple of vintage radio Face Book pages I follow.
Mr Carlson could make tons of money on daily tour and a bed and breakfast.
For $500 a night you get to met Mr Carlson, sit for a one on one white board design session, eat lunch, watch a video taping, tour the Mr Carlson personal equipment hoard and a ride in the bucket truck.
Where do I put my credit card info?
The ride in the bucket truck sold me!
He probably makes more just by doing repairs and it's less fuss lol
You sir are a brilliant technician, I wish I were your neighbor.
I was a TV tech for 40 yrs....
Love your skills, I would be at your lab everyday..😅..
Best wishes Paul.
To the beginning, a general comment about Mr. Carlsson's Lab videos:
Excellent English and with excellent articulation. The vast majority of TH-cam video creators should learn from this. I am not a native English speaker and I can understand Mr. Carlsson's speech perfectly.
The same applies to speech parsing. Consistent and clearly progressive. A real talent!
Just got into antique radios. Your videos have been amazingly helpful. Thank you
Great to hear!
12:30 I've definitely had an "oh crap" moment when I was trying to rewire stuff after taking a picture, and I couldn't tell where a particular wire actually terminated!
Thank You for another Learning/Educational video. I am now a Patreon supporter ($10), and I look forward to your projects and videos. I am a Luxman Fan boy with a number of 70's Tube and SS gear.
Welcome aboard!
great video,! I have jumped full in to this old tube stuff, amps and radios test gear. The depth of your videos is second to none and you have taught me so much about this dying art. I i have 1 patreon account and its your content. consider me a huge fan and thanks!
Thanks for your kind feedback!
Beautiful piece of equipment, tbh its the only piece of valve gear you would ever need
and yet, another great video!!! thanks Paul for showing us some more of your knowledge and skill!!! mike
Great stuff. You can say it was "just a repair", but really it was an excellent rebuild of the headphone amp and a nice analysis of the original issue. Nice work very enjoyable. I am getting allot better at the SMD work, trying it for the first time on your Ultra Probe. On a parts hold for the amp/demodulator but the circuit board is ready. It will go in a cabinet with speakers built in. Getting excited about it.
40:27 Much of these Japan electronic stuff DO NOT have Philips head screws although they make look to the eye to be Phillips. Instead they are JIS and a different shape. Trying to use a wrong spaped tip will stripout the head.
Same with vintage Japanese motorcycles. It can be a real challenge if you want to save the screw even with a proper-fitting bit.
Luxman also made kit power amplifiers...which used oddball Japanese output tubes, of course.
Hi Paul,
I liked your choice of beginning and ending shots. Nice change from your wide shot of your bench. Oh, and your content, as always, was very informative. Cheers, Scott
I worked in Japan from 1985-1994 and towards the end of my contract I used to see so much faulty Luxman and Sony ES gear for pennies in the recycle stores, I was always so tempted just to fill a crate with the stuff and ship it back home but it never came to fruition. Visited a few years ago to go snowboarding and couldn't help have a spy in a junk store and they still had some luxman gear but it was top dollar now :(
Nice attention to detail though on the repair of this amp and for reminding me of days gone by
I worked in a TV repair shop for 16 years, starting in 1971. One day one of the guy's routinely pulled the back off a TV set, and found a flashlight inside. It had Japanese writing on it. We all assumed that somewhere in the manufacturing process an inspector accidentally left it inside the set.
Very nice work! We could benefit from your reasoning regarding replacement transistor selection.
Another great informative video. Still waiting for the follow up on the old BC348 receivers. You very detailed and I learn so much just watching you. Thanks for the additional info on matching transistors and the freq sweep. Glad you explained that.
Great video highlighting a great preamp. Really appreciate your schematic walkthrough and troubleshooting explanation. One thing I’d like to see you spend a few minutes comparing specs of the new transistors to find suitable replacements. Also, what you look for to decide if the bias resistors need to change for the new transistors. Thanks again for your great videos - I’m learning so much!
Nice! I love high end audio. MORE please!
I dont know anything about anything.. The symetry they put in that small board. I can 100% appreciate that. That means whoever designed that cared about it. At least a little.
I laughed when you said "somebody needs a better pair of glasses!" Typical Mr Carlson politeness! Screwing down the transformer and pinching the leads is very bad. I would have said something much worse!
Good job Paul!
41:19 The head chew up is most likely due to the person not using the correct type of screwdriver.
I assume Paul is using the proper JIS screwdriver for the Japanese screws.
If you work on Japanese radios and equipment, please invest in the proper JIS screwdrivers (available on Amazon or Jensen Tools). You will thank me, and your customers will thank you for not chewing up the screws in the equipment your servicing.
73, Jim W7RY
Nice preamp but Luxman insisted on using thin phenolic substrate circuit boards. Even the top of the line CL-35 used them. Around this time even Dynaco was offering the venerable PAS-3X with glass epoxy circuit boards. I know, I have one!
16:00 I expected all transistors to be dead, as you showed the board in place I thought hmm 100 volts - bang! The whole board will need replacement. At this point I'm thinking power supply repair. Let's see (un-pause). So a momentary short by someone OK.
I don't think they jumped anything on the drawing, they just drew the 2 point contact switch in the correct order. From the phone jack the "wrong drawing" they connect the close contact to the jack instead to the common point of the 2 way switch. In other words in the "correct drawing" they just swapped the switch 180 degree so that the phone jack input goes to the common point of the 2 way switch now.
After 25+ years of buying & paying for repairs to vintage gear I've had enough pro gear has gotten reasonably affordable and specs out better then older gear I spend more $$$ buying/repairing vintage gear then the cost of new gear. I have two Heathkit Power Amplifiers AA-1506 in for a complete rebuild mainly because I built the bi-amp open baffle speakers system to match them these will be the last of the vintage gear for me.
Yesssssssssss. Hands down, the best TH-cam channel. I really appreciate the effort you put into this channel
One additional thing to check: I would have opened that octal plug that goes into the power supply. There could be a stray strand of wire that might have shorted between the 8v and the filament line. Having said that, chances are that what happened is exactly what you described. The "technician" probably heard a pop, but then the preamp's main output continued to work, so he thought he'd dodged the bullet.
Why not fuse the 8V section wire? Wouldn't the fuse prevent blowing the transistors in the future? KR7KZ.
Thanks for the great explanation during this video of what you're doing. I learn alot watching them. Also, excellent video work showing the circuit details; very high quality.
I've run across the pinched wire scenario a couple of times. The error was caused by sloppy assembly and testing methods: using unskilled labor as assemblers, no torque controls and no hi pot test. Often a wire pinched like that will not short immediately and the unit will pass a simple function test but over time and especially with elevated temperature to soften the PVC jacket, it fails.
I like watching you do repairs, you make it look so easy and enjoyable.
"Somebody needs a better pair of glasses."
Dang, that is bad workmanship to pinch wires like that, in such a clearly visible location.
That looks like a standard oscilloscope. You converted it into a curve tracer? I would like to learn that trick! In the past I would use a device called a Huntron for that purpose. However, they were very expensive to own. I had wondered if one could turn an o-scope into one for a while now. Looks like that is definitely possible. I am still early on the video and I am wondering if someone might have put the power supply connector on the wrong way and the pins were misaligned with one of the higher voltage pins being placed on the 8 volt line. As you mentioned, a stray probe lead when testing would definitely be a culprit too. Edit: Looks like you answered my question later on in the video! I am definitely interested in that mod!
Nice and very interesting video about those japanese components. A classic issue with these 100V supplied units is many are tempted to check if any primary winding is available for "international" conversion and other primary voltages. But hence specifically described and checked, it's rarely the case. And it could explain some bad manipulation with some direct short from primary or B+ and all these tampering with screws and wiring. Some should definitely tell to those collectors to be really suspicious about every Japanese material. They're easy to find on the net, but difficult to use if you don't have the adequate rare down voltage transformer (here in Europe with a primary 230V AC supply, it's unobtainable over a certain power limit!). And as you could expect with any tube material, the exotic and never the same B+ is even more difficult to source.
At least your 230v supplies usually have a different socket type. The plugs on 100v equipment are the same as our regular 120v plugs so it's easy to apply the wrong voltage without thinking.
@ 7:58 OK if the circuit looks like that, how bad did the eardrums, ossicles, cochlea and auditory nerves look in the person who was wearing the headphones at the time? Yikes!
It's good to be able to clearly read the resistor colour codes :-)
From the look of that power connector I bet it is possible to engage at least two pins even when key is not aligned. So the headphone circuit might have been fried by someone trying to jam that connector on while the power supply was active.
I used to work in a hifi shop. A receiver came in . It had a sticker on it . " Genuine Simulated Walnut Veneer " .
While most people say "knock on wood" I usually say "knock on simulated wood-grain finish" :)
I never was a big fan of fake simulated walnut veneer. :-)
Reminds me of those early Sherwood hifi amps and tuners in their metal cabinets covered with what Sherwood called ''walnut-grained leatherette''. 😀
@@fotoralf I have a Kenwood with a metal cabinet (KR-77) that has a painted on simulated walnut finish. Also a Sansui that's wood, (331) but with a vinyl simulated walnut wrapping. At least they saved a few trees so it's not all bad. LOL
I'm in the process of applying new veneer to the casing of a Pioneer SX750 receiver; the "genuine simulated.." original had a paper thin layer over a plastic backing - a nightmare to get off but I hope the results will be worth it.
Excellent as always! Greatly appreciate seeing the mix of vacuum tube and solid state based electronics. Thank you.
Love your videos. I'm currently building a Nelson Pass Class A amplifier (His Burning Camp design sold by DIY Audio). Next I'm going to tackle re-capping my 40 year old Hafler DH-110 preamp which has no line output although the headphone out appears OK. Cheers KN4MNA
It's been a while I watched your channel. Forgot how interesting and instructive it was. And often the treat is to learn about the repair stories of the devices, like in this video.
And meanwhile, I bought myself the Hakko desoldering gun. It's like a dream.
Thanks for the lessons
Lucky who ever did lousy work did not get a Leathal Shock.
Very nice work Mr. Carlson I lke your snazzy solder sucker you use and the tracer nice Carlson design.
Thanks for Always warning everyone about The Danger of the elevated High voltage in Tube equipment..
Cheers
#6:37 - It appears that the 'center' and 'up' terminals of that switch were swapped as well.
Excellent video Paul! One possible reason for the chewed out heads on the case screws of the power supply could be the use of Philips screwdrivers on a JIS head. This equipment being Japanese... I would hedge my bet that the fasteners used would be JIS. While it is common to see the tell-tale dot stamped in the head of a JIS fastener, it's not always the case. I did training at the JRC factory in Mitaka in the early 90s and was instructed that Philips screwdrivers are NOT to be used on JIS screws as they will cause damage.
Another great repair as always Mr C..👍👍 In depth explanations of circuit analysis with schematics are always a bonus in your content, thanks for that. Beautiful piece of equipment, glad it was reparable without major stress and the power supply surprises, well...wow! Thanks for the video and work, much appreciated. See you next time. 73
I realize that there are those caps to protect the output but could someone have accidentally fed in power from the headphone jack? What if their headphones came into contact with 120v?
Hi Mr Carlson would you be able to cover everything you look for when replacing components to know what would be a suitable replacement thanks for the video really enjoyed it as always and keep up the good work
Still think you and shango066 are the best channels on youtube.
Commented that 5 years ago but still the best.
Thanks for your kind comment!
I bet Mr. Carlson's place was the best movie house in 🇨🇦 The type with the neighbors who can hear Jurassic Park from 2 houses over.😂
As Always, Paul is not just creating video to watch, but teaches techniques, tips, what to "keep in mind", fine repairmanship and bonus incident investigation. you are a ballerina of electronics :P. Thanks a lot and keep it up, more power.
That Fluke Scopemeter... Wow! Drool!
Hi, I'm a 5 year old electrician, and I've been watching your videos with my mom and dad. I love them. My favorite part is watching you take apart components. I think it's funny when you call capacitors 'caps.' Please make more videos with your homemade leakage tester.
The classic 70s look outside, my favorite to this day, but with tubes inside, nice.
I think my dad had one of these when I was a kid in the 80's We had TV/Stereo surround sound before it was a thing you could buy at Wal-Mart
9:30 Maybe someone tried to reconnect the Octal power connector while it was powered on, and perhaps the Octal index slot is insufficient to prevent a rotated-offset connector from briefly applying the PS voltages to the wrong pins. Maybe... Maybe not.
49:00 Skipping ahead, yep. You're thinking the same as me. 🙂
Fascinating as always. Always enjoy your amazing knowledge on these projects.
Glad you enjoyed it
Fantastic work the best job ever calm thoroughly intelligent easy to understand and meticulous precision to watch is like watching a master class in electronics bravo Mr Carlson 🎉
Carlson's quote of the year so far -- "Somebody needs a better pair of glasses" 😂
i see the algorithms are favouring you, just a little thank you, as i was recovering from a stroke just before covid lockdown, i always seemed to by directed back to your ft-1000mp repair
you gave me the idea to reactivate my ham licence M1DLS......... . the tinkering and shack fittings also helped with the recovery,
i now own a ft-1000mp and a few others,
my latest obsession, is to sync forgotten radio's i:e ic-735-- ft-840 with sdr software giving the old girls a face lift...... ham's dub it as a pan adapter
anyway i'm rambling, thanks for the nudge, love the equipment you use lol
Nice change-up Paul. Always enjoyable no matter what you're working on.
Mr. Carlson, I have a 1961 Gibson GA - 2RT Maestro Deluxe With the Reverb- Echo Amplifier Tube type and I dug it out and put it in a shop for them to check it out for me and the only thing wrong with it was the speaker so I had him to put a new original one because I wanted it to be all original, It has 2 guitar plugs & 2 Mic plugs + 1 plug for an extra speaker, I’m thinking about selling it because I can’t play a guitar, And I have a 1963-64 Silvertone Black Sparkle with Amp built in the carrying case, Guitar like new and has a little static in the amp volume/tone & tremolo knobs, everything is in very good condition, The guitar man said he wouldn’t charge me anything to clean the static out of the amp, I’m almost ready to sell that one too + the other amp it works like the other one but don’t have the guitar or the foot switch
I am 61 years old I have been a student of electricity most of my life ( 3 or perhaps 2 years old )
and I have to say you have a very good work place there
I have a small work / computer station a pc type Hantek scope , DMM
I hope some day I will have a real Lab work station .
Thanks Mr. Carlson!
You are very welcome!
Another great Video Paul. I"lm well beyond the need to do anything anymore. not a "paid bench tech. just an average Amateur Radio op for 60=yrs. made my fair shareof smoke on projects. and at 80 yrs old I can still learn things what ? for? who know I might getthe doldering iron out again before I croak. Oh! thermal bit on the diodes had an old timer (back when I was 20) toldme abut that one nice tip thanks for sharing. ECF
Hey paul, im looking for a bit of advice regarding a stereo preamp, im looking to build one into my BUSH DVD player and fit a front headphone socket, however every one of those cheap preamps ive tried from amazon sound horrendous with more noise than actual music output, could you recommend me a good small preamp that runs on either 5v or 12v please?
cheers.
Ha! Back with the curve tracer action :). I built mine and use it sometimes - and I'm glad to you for the ideas!
That was indeed a bunch of baaaaaaaaaadly discombobulated transistors. Nice investigation of the possible root cause.
Thanks, Paul, for another fascinating video. You are an amazing person with your attention to detail. I could hardly believe it when I saw those wires trapped under the transformer bracket. How anyone could fail to see that is beyond me. All it needed was a quick check before refitting the cover and the person would see them. The sine waves looked nice and clean after you replaced all the transistors and they were obviously pretty well matched too.
Thank you very much, my friend, we are from the same professional field, I am a naval technologist, in the radio field
Critique a capacitor is an art. Great repair and debug to what seemingly would be root cause, I bet it was. Very fine line between a capacitor and a 'crapacitor'. Thank you for sharing!!
Nice work my friend!
The other problem with cameras is colour balance, I've had red wires appearing pink, but there were also pink wires present as well. That lead to a "paracetamol event". 😆
This channel is the best 😊
You just proved Tesla was Right....Free Energy..as your Caps wirelessly recharged !!
🎵 SCIENCE.. BLINDED ME..🎶
🇨🇦🤓🤙
I've come across this problem a few times over the last 40 years, it was very common to use the power amplifier to feed the preamp via an umbilical that often terminated in an octal connector. Issues were usually because someone had broken the keying peg off or the umbilical connections had become fractured with repeated movement and connections...
Never had any other problems as far as I remember, nobody managed to shove/force the connector in the wrong place, and its usual to fiddle about to find the key, but unless there is another problem the connections do not make until the connector has mated with the key. But after 60 years they can look a right wobbly frayed mess!
Worth checking his cable for issues. I would before I let him blow up my work on his headphone amp.
Edit: then you mentioned it.
Well done, Paul, I really enjoyed this one. I'm just wondering, where do they use 100 volt mains electricity? As you'll know, We're on 240v in the UK, and for the life of me, I can't think where they might have 100v. BTW, being on a higher mains voltage here used to have its disadvantages back in the day, as transformerless TVs and radios, ect, had massive mains dropper wired resistors that got absolutely red hot!
@steviedx1710 Thanks Stevie, I never knew that! I always thought they were on the same as The US. But then, as my dear mother used to tell me "You know what thought did? He followed the shit cart thinking it was a wedding" !
@steviedx1710 Yeah, Mac & Barney found out that Japan uses 100 Volt line voltage in January 1960. (If you know, you know... See RF Cafe for more information.) Not only that, Japan uses both 50 Hz and 60 Hz. Eastern Japan is on 50 Hz and Western Japan is on 60 Hz. This is an accident of history caused when they electrified the country. They bought some equipment from North America and some from Europe. Now you know why most Japanese equipment that relies on line frequency (tape recorders & turntables typically) come with capstans or pulleys for both 50 and 60 Hz.
I remember on the Price is Right '80's they would have Luxman component stereo systems on the show. Sheer cream of the crop!
That must have been quite a fireworks show when that amplifier unleashed the magic smoke. 🔥😳 Watch those probe tips! ⚡
I like Luxman equipment. I have a Luxman TP-117 Receiver/Preamp from the late 80s, and it STILL sounds VERY nice when compared to modern Hi-Fi stuff.
Rite Paul, Very nicely laid out, have to start calling you Sherlock Carlson, nice bit of detective work on the ps! TFS, GB :)
While the pinched wires in the transformer might not have cuased immediate harm, it does have some possibility though... I imagine someone could have "bumped" against the power supply while it was on (or connected, depends on what wires were pinched) or it might have had a slight drop from a shelf? And that might have levered the transformer around a bit more to create a momentary short between the AC line and ground... could IMHO possibly cause a voltage spike in the circuit... tubes will probably handle a "ground oops" just fine but the transisotrs might not...
0:58 Octal Power Connector. Oh, look!! It must be plug-compatible with the Eico 753 Ham Transceiver. Let's plug it in and see !! LOL !!!! 🙂
That was nice, but I would have run a spectrum analysis at several (many?) frequencies, showing input and output spectra and coherence, etc. (white noise?) on both channels. Yeah, I have all of that "stuff"!
Otherwise, nice job, Mr. Carlson!
Aside from the real Tektronix tester and the heathkit tester mod you have, do you have a video on gain testing silicone transistors at spec temp, stay TO-3 package? Is an Atlas device good enough? Would that topology be considered quzi-complementary?
This 76-year old male says your Luxman video reminds me of the Dynaco Pat-4 stereo preampifer and 60-watt Southwestern Technical Products, (Motorola?) stereo amplifier I had in the early 70's.
Luxman, is The King of Weird! Luxman had their own custom designed tubes made that were only used in Luxman amps. 100 volts only is old Japanese. Some prefectures in Japan still use 100 volt mains. Fiji used to be on a 100 volt system too. Some of the Luxman power tubes are totally unique and another batch was just USA made 6550s with bases that only allowed them to work as triodes. Luxman has a cult following.
Mr Carson do u have anybody to talk to.. My mates grandad used to service Communications equipment during the World War when battle were going on for the British Army... He told me he serviced kit with 80 valves in it...
Mr. C. Happy New Years !... Could you put a fuse in the power line going to the head phone jack; to prevent overload ?...(I know next to nothing about electronics )
Another great video! I'd love to know what that multi-output DC supply on the bench in the background is. Just can't quite make out the brand/model number.
One wire crushed under the transformer is bad enough, but two? Awful. I see tampering like this all the time in camera repair. Thank you for the great video. In my youth I built Dynaco's and Heathkits. I still have my Harmon Kardon Citation IV and V which my dad built from kits.
Thanks for all your knowledge sharing, mr carlson.
Can I suggest a class?
All technicians have dificulties findind the equivalent of a given transistor.
Could you teach the best way to find an equivalent transistor?
Thank you
Jorge mendonca
Awesome as Always... Thank you for such cool content.Pleasure to watch and learn
I've a few Luxman products made in the mid 70's. High quality components used on the boards along with top notch cosmetic construction. They don't make them now like they used to unfortunately.