Sony TA-4650 V-FET Amplifier (Part 4 - Restoration Complete!)

In this video, we finally reach the end of the journey, restoring the Sony TA-4650 VFET amplifier. It has been a long project this one!

[@whatcouldgowrong7914]

In the final video I will also go over common questions around tools, grease etc and give a parts list of capacitors and transistors used 😀

[@RegiPavan]

Absolutely gorgeous restoration

[@whatcouldgowrong7914]

Thanks! 🙂

[@PeterDyall-bn7ut]

Certainly is stunning. You’re setting the bar very high!

[@whatcouldgowrong7914]

Thanks! 🙏

[@mikemmikem2758]

I love your work ethic and attention to detail. Absolutely gorgeous restoration. I could easily watch an hour of your videos (and I'm sure I'm not alone in saying such) so don't shorten too much. Thanks again for another super cool video.

[@petertimp5416]

XrayTony would be proud, good job. Just subscribed 😊

[@whatcouldgowrong7914]

Welcome! Thanks for joining :)

[@mistermac56]

Excellent work. The silicone pads are so much better for thermal than mica wafers and heat sink grease for the V-FETs.

[@whatcouldgowrong7914]

Yup I hate thermal paste!

[@adrieltzu3565]

Absolutely beautiful job. Sometimes ocd is a good thing.

[@whatcouldgowrong7914]

It can be a blessing and a curse 🤣

[@adrieltzu3565]

@@whatcouldgowrong7914 I have it too, and can't enjoy my gear unless I know everything is sparkling clean and correct. There's a little of the TV detective Monk in me as well.

[@LuizMoraes-fn5ir]

Fantastic work. Greetings from Brazil.

[@waynemarc77]

I OWENED ONE OF THESE!!!

[@ukrainehamradio]

Great job!

[@MrJohnBos]

Beautiful restoration, the amplifier is stunning indeed. Better than new. I think you could definitely cut way down on the time lapse. I'd much rather see and hear your thoughts on why you are doing what you are doing. Other than that, I loved the entire series on this amp, well done.

[@holtonaudio623]

I bought one of these amplifiers brand new back in late 1978 for $600AUD if my memory serves me correctly. A friend of mine in the day had the TA8650, much bigger amplifier power wise and it sounded great on a pair of La Scarla Klipsch loudspeakers.

[@johnny-z]

Wow! A Brit w/ a toothbrush. I didn't think that had those in Jolly ol' England.

[@supernovaf1]

Huh? He's not a Brit!

[@EliteRock]

@@supernovaf1 Yanks! All got tin ears.

[@markwroblewski6500]

Nice clean job.What's the brand of the suction pump you are using.Looks very effective.

[@whatcouldgowrong7914]

It is very good, its a GOOT solder sucker, had it for over a decade. It has its bad days but its never has anything replaced on it and should probably get a new one. Only problem is it’s not single handed use but I just use my hip to reload it

[@markwroblewski6500]

Love your perfectionist approach.2 questions - What's the make of the green soldering iron you're are using so skilfully?As well you've mentioned pairing/coupling of transistors.How would you pair NPN/PNP output ones in a Class 'A' power amplifier[Krell for example].Many thanks in advance.

[@whatcouldgowrong7914]

It’s a Thermaltronics TMT-9000 inductive soldering iron, had it for a decade :) Inductive soldering irons will change your life, no waiting for joints to heat up / turning up or adjusting temperature etc

[@adaboy4z]

You have a parts list for the power supply!? Enjoyed the series!!

[@whatcouldgowrong7914]

Yup capacitor / transistor subs will be shared in the final video once I confirm everything is happy and nothing goes wrong after a burn in / testing. Doesn’t include the resistors but I just took those off the PCB service manual list which was accurate 🙂

[@jackalterman]

Really well done! I enjoyed this video, including the sped up bits. (I also appreciate the cleanliness of your bench and work in general.)

[@repsych]

Thanks; what is the solution that you use in the ultrasonic cleaning machine?

[@whatcouldgowrong7914]

Ambersil ultrasonic cleaner with some IPA mixed in :)

[@garygranato9164]

noob question but why would he change out good components ? particularly the resistors ?

[@whatcouldgowrong7914]

Good is debatable these days, amplifier is almost 50yrs old and everything degrades. Capacitors are mostly fine still, transistors have drifted too much and needed to be changed / some are known to be problematic. The other resistors, some were a service bulletin, some had failed and the others i changed were in the signal path with high modern high precision resistors to try and improve thermal noise. Was it working before I started, sure. But as I said you get one shot with the VFETs and if something fails absolutely damages them, the amplifier becomes useless unfortunately.

[@ABC-rh7zc]

It clearly takes up too much space on your bench. Happy to take it off your hands, no charge.

[@whatcouldgowrong7914]

That’s very gracious of you 🤣

[@jagrutbhatt3301]

So disappointed ...not found any sound demo in the end🫤😟🙁☹️🥺🥹

[@whatcouldgowrong7914]

A final video is coming 🙏I need to do it justice and spend some time with it

[@iceberg789]

except bare boards and cabinets everything got changed. 🤔

[@whatcouldgowrong7914]

Its a 50yr old amplifier… the boards are original, everything was changed based on ensuring it keeps working for another 50yrs

[@tinsoesoesoe1346]

Please give me some circuit diagrams.

[@whatcouldgowrong7914]

All the documentation is on HIFI engine / google :)

[@savvassidiropoulos5952]

Those time lapses are not doing justice to the work. I understand the reasoning behind wanting shorter videos, but I don't mind long good ones. Perhaps showing important details for each section in real time? Or including chapter marks so people can jump these sections if they are bored with details? Anyway, it was my first time watching your work and I need to offer my compliments to a job well done.

[@whatcouldgowrong7914]

I agree, I’ll ponder how I can strike a better balance, split more videos or something, unfortunately I can only go off KZbin analytics and long videos seem less popular. Thanks 🙏

[@ianc4901]

When you speed up the video so much it's not possible to see what you are doing so it gets to be just a blur, I had to skip those bits to get to the commentary because it's kind of annoying trying to figure out what's happening. Having said that I do realise there are people who will run the video at slow speed so they can see as much detail as possible and would prefer to watch a 2 hour video of desoldering, installing and resoldering components !

[@whatcouldgowrong7914]

Hence why I asked the question, it’s not really possible to accomodate every who wants reasonable length videos and time lapses as these videos take place over many hours of work and are already cut down 🙏

[@ianc4901]

@@whatcouldgowrong7914 If you had a second channel showing uncut 4 hour videos of the entire process there are people who would love it ! They would probably complain you didn't upload enough for them too !

[@BaskaranBaskara]

Rummy circle vilambaram podaathadaa they..., paiyaa