Sony TAE-8450 High End Preamplifier Restoration

In this video, I completely restore a gorgeous Sony TAE-8450 Preamplifier. This is the first of a two part series, which will also include the venerable Sony TAN-8550 VFET power amplifier.
This was a very fun piece to work on, as Sony made it as service-friendly as possible. Most of the circuit boards are modular, making removal and installation a piece of cake. The internal wiring is also as neat and well laid out as much of the high precision test equipment I’ve seen. The 8450 has a myriad of inputs and features that make it a perfect preamplifier for someone who has many sources in their audio chain. It sounds wonderful and the PPM meters are very cool to see in action. It all comes together to make a great preamplifier that is a joy to both work on and listen to.
If you enjoyed this video, please like and subscribe if you haven’t already. Comments are also appreciated, as it creates interesting conversation!
TheVintageKnob article:
www.thevintageknob.org/sony-TA...
Audio-Database:
audio-database.com/SONY-ESPRI...
HiFiEngine:
www.hifiengine.com/manual_lib...

[@johnnyg1700]

One of the best HiFi restoration channels on KZbin. Thank you. Keep them coming please. 👍👍

[@PrimeHiFi]

Thanks! More to come!

[@welderfixer]

This unit looks like it was made by Hewlett-Packard or Tektronix. Two thumbs up!!

[@jefftobin4034]

My thoughts exactly, especially those green edge connectors.

[@johnsmallberries3476]

Thanks for leaving the "mundane" stuff in - it's actually helpful and fun to watch ⚡👍

[@stephengrey1880]

That VU meter is incredible, great content, thanks.

[@Compact-Cassette]

It's great. Incredibly impressive design, so strong, stylish and gorgeous. Thank you very much for the wonderful video material.

[@rods6405]

Great work! Sony's build quality and great documentation is one of the reasons I went to work for them! This range of products was outstanding I loved repairing them! Funny we never measured the caps but did check THD!

[@leerothman7570]

I sold audio gear back in that day. Loved the TAE Sony stuff. Had a VFet amp of theirs that was superb. Miss those days.

[@voenixrising]

The TAE-8450 retailed for $1300 in 1975 ($7263 in 2023 dollars). I remember seeing and hearing this entire series at Jerry's Audio in Phoenix, AZ. I was a junior in high school at the time and they were obviously WAY out of reach financially-and STILL are!

[@Guitar5986]

There is a saying that any repair/restoration work should match or exceed the OEM. You are the prime (no pun intended) example of this. Beautiful work.

[@tee-jaythestereo-bargainph2120]

State of art !

[@shaggyburn]

This clip works so well because of your passion for the unit. Keep up with the statement pieces.

[@keithtrauner1738]

Great work as usual. VU meter was fascinating - what an amazingly complicated mechanism to show an electrical signal.

[@keithtrauner1738]

As a follow up, wondering what other brands/models of vintage gear you find easier than most to work on?

[@PrimeHiFi]

Thank you! All brands have their ups and downs. In my experience, the higher end the product, the easier it is to work on. There are some exceptions to that though. I love Accuphase, Luxman, certain Pioneer / Marantz / Denon / Kenwood, etc etc.

[@MariusHiFii]

Hi and thank you for this video, soon i will have one for restoration. Good luck and keep going ! Cheers !

[@ThomasL]

Stunning work as usual. Utter professionalism.

[@AudioElectronicsChicago]

Looks great

[@Stelios.Posantzis]

Some happy owner must be watching this probably anxious to get it back!

[@Brian-mp6bg]

Great video, love the format

[@seb-57]

Wonderful video. Really enjoyed the very thorough job in the restoration, both sonically and aesthetically. The astonishing result is a testament to the skill of the technician. I am sure that the Sony Corporation will also appreciate seeing these flagship products being restored to this level. Thank you!!

[@PrimeHiFi]

Thank you!

[@curtwow]

❤ I have one it's easily my favorite piece in my collection! Amazing job on the restoration. It really deserves that level of service. My tech did a great job on mine. It sounds so sweet. One of the things that attracted me to it was the headphone amp section which is mentioned on head-fi.

[@robertwear1675]

Great job! I found one of these at a great price and bought it. It sounds great especially the phono. Pots and switches need a good cleaning though. One channel or the other drops in and out. The phono gain. Switch on the back is the main culprit.

[@PrimeHiFi]

Thanks! Enjoy :)

[@jitrapornpha5104]

superhuman skills, and here’s me beaming at my wife when i solder a speaker cable

[@batmandestroys1978]

Work of art! Man you are so chilled! Great dude!

[@PrimeHiFi]

Thanks!

[@batmandestroys1978]

@@PrimeHiFi Thank you! Your videos are absolutely awesome! The presentation is better than any TV presenter in any field!

[@BAGINAZARD]

I also have the service manuals for both.

[@miguelLinaresmmm]

Hermoso trabajo

[@ralfralf7443]

Super Arbeit.....mehr davon Greetings from Germany

[@PrimeHiFi]

More to come! Thank you

[@BTW...]

I share your dedication an appreciation of high quality craftsmanship. re. the wiring looms - Macintosh equipment was built to such quality standards too. I've much pride in wiring work I've done for high quality Standard Protection and Control panels (HV Generation / Distribution / Protection and Industrial process control fields)... looking better actually. I was taught that just testing and working correctly was half the job. ;-) I see no curse in perfection. Also note the ~ +10mm length in wire loop from loom to connector. This allows for service work, allowing re-termination in future if needed. Nothing worse than tight like bootlaces. I've done the same in home CB distribution panels. It saddens me today that the same Standards don't apply, but clients immediately recognise when someone who cares has worked on their equipment. They come back for more, even if the quoted price is higher than other service providers (+10% easily) Keep up the good work... never let some boss demand you work faster and let the quality slip.

[@PrimeHiFi]

I wholeheartedly agree! Thanks for watching and for your kind comment! More to come soon :)

[@fredsk1]

Dunno what I'd do without my Peak ESR70. If you haven't already done so, grab the needle probes for it - super handy for spot checking caps.

[@atw4321]

Wish they were all built that way im restoring a sansui au719 it's not that hard but would be much easier to disassemble if it was all on pull out cards ..Nice job

[@pernilsson2512]

Very Nice Work I have a Sony TA-E90ES and TA-N90ES Interesting that 30 years later Sony went with no controls just basic volume and source switching.

[@BAGINAZARD]

I have a Sansui B3000 and a SANSUI SE-2000 that could use a restoration / upgraded parts. How can we make it possible?

[@Sigmatechnica]

I want one! :D

[@chumleyk]

This is the definitive KZbin channel for this type of content. Bar none. However, when the meter is switched to the middle setting, I swear the vu/peak should 'decay' much slower than they do on this one?

[@senzaur]

Nice video mate, love from Jowett96❤

[@PrimeHiFi]

Holy shit man, blast from the past! Hope you’re well bro! If you have discord hmu my handle is connorg

[@randallfawc7501]

I have a mid 70s Sony STR-7035 (that I bought new in 78) What would you think of an issue with the FM tuner slowly drifting off channel until nearly all reception is gone? One issue I see is the boards do not look to be modular.

[@mchabbi]

Never seen a better built 70s audio gear. It probably looks (and performs) better than new now. One small suggestion, if possible, please hold the camera or the part longer in one place, moving either one of them frequently makes it harder to watch (or read and see whats on those boards)

[@PrimeHiFi]

Thanks for your kind words. I recently got a tripod which I have been using for the new Sony TAN-8550 video. Stay tuned!

[@h0ll0wm9n]

Great video, with excellent camera work, editing and narration. Yes, those late 70s Japanese solid-states are unique. About replacing electro caps ... yes, even ones which test okay with ESR meter are worth replacing as true cap tester (one that shoots voltage and current thru device) will reveal flaws. Also, it is best to stay as close to orig value as possible. Yes, it's tempting to "upgrade" to higher uF value. But this can degrade sound quality: loose bass, loss of speed and dynamics. Stick with orig schematic values.

[@PrimeHiFi]

Thanks for the kind comments! More to come soon

[@philshifley4731]

Hello Prime HiFi. Great video and a wonderful piece of audio gear. If you could please share your method for cleaning the boards after they are reflowed. Thank you and keep them coming. Found what I was looking for at 39:23

[@PrimeHiFi]

Thanks for the kind comments! Glad you found the information you were looking for :)

[@tee-jaythestereo-bargainph2120]

Hey man like to try and upgrade all the parts in my new Dynaudio Tower speakers they do look legit for real has 1st 2nd and 4th order it's no 1 circuit desighn but I wonder how high quality componetes would sound any better It should ' what you think ? May make a good video ' hit me up later tonight if you can '

[@danhorton6182]

Nice work, and excellent video! May I ask what made you decide to replace the 2SC1124 and 2SA706 outputs transistors with MJE15032 and MJE15033? While being a good choice as they’re wayyyy overkill and will last forever there, they are quite a bit slower than the original. You could have gone with KSC2690 and KSA1220, would still be overkill and have a much closer transition frequency at 175 MHz. Or even the Toshiba TTC004b and TTA004b, again overkill, but much higher 100 MHz Ft. Curious as to what made your decision.

[@PrimeHiFi]

Thanks for your kind words! A quick explanation as for my choice - fT specifications vary considerably when testing conditions change. Generally, fT will increase as the collector current decreases. Because these transistors are used as a current buffer for a headphone amp, they will never see much stress, so their fT in theory should be greater than what the data sheet specifies. They still wouldn’t be a perfect match in terms of fT, but I believe the fT of these devices is relatively arbitrary with respect to their use in the circuit. It’s not a high speed circuit by any means, so the MJ’s work perfectly in place of the originals. I did take measurements to make sure there is no parasitic oscillation. Distortion measurements of the headphone output also suggest the circuit is working to par. I could have used a multitude of other transistors, but I have a very large stock of these MJ transistors on hand and they are bulletproof. Thanks for the question!

[@danhorton6182]

@@PrimeHiFiwell that is certainly true, they will be bullet proof in that setup. Love it. Can I make one suggestion, and it isn’t a criticism. I love seeing what people are listening to, so maybe at the end of the video when you’re showing the piece you’ve just gone over you could show and tell what amp or preamp it’s hooked up to, what speakers you’re running. I got a very tiny peek, but we’re those Met 7s?

[@mcgyveramphol7092]

😊Hi, How did you reflow & reflux on solder side PCB? And what kind of solvent that use for for that job? Thx .

[@PrimeHiFi]

Hello 😄 I usually coat the board in liquid flux and reflow all solder joints. I use Isopropyl alcohol to clean all the residue off when I’m done. Thanks for watching!

[@rinkerlaw7446]

Nice work. What is your secret to getting such a clean cutout for the IEC connector?

[@PrimeHiFi]

Thank you! I use a "nibbler" tool, followed up with a file. Usually works perfectly!

[@robertwear1675]

Did you replace D1905 and D1910 which are 1T243M's? If so, with what? Thanks.

[@PrimeHiFi]

I did not, but there is a great source of information on these diodes here: audiokarma.org/forums/index.php?threads/the-final-word-on-sony-1t243-1t243m-devices-measurements-and-substitutes.1003892/

[@robertwear1675]

Thanks for replying. @@PrimeHiFi

[@tee-jaythestereo-bargainph2120]

Dollar vs Dollar Today the Sony would easily be a $10k amp ' build quality in the 70s was crazy for the price us Americans could get these Amps Back in the 70s built in 'Japan" for 1U.S. dollar equaled 400 yen Today it's 1 U.S. Dollar equals 90 yen ! ! Food for thought Thanks Conor I still have less than 100 hrs on me Sansui Au717 CG-Edtion 😆 Trying to keep 💯

[@oturgator]

What a coincidence, I have the same pair that I have restored just recently and they are my daily drivers. Looking forward to the next one. One question, all the transistors you have replaced are available as new-old-stock. Do you think that using NOS components is just being too cramped and overly purist? I know that, whatever happened to the replaced transistor (moisture ingress or corrosion) can happen to the NOS components, or as Tony says, worse can happen to the NOS component as they do not go through heat cycles that can improve the moisture ingress, but the tonal signature of the component is dependent on the choice of components and one may say that the transistors are a major part of this.

[@PrimeHiFi]

I think the replacement of semiconductors with brand new parts can be crucially important. There is generally zero reason to buy NOS components with unknown quality, origin, history. If you buy new while paying attention to component parameters, you will be much better off. Just my two cents :) thanks for watching

[@brianbervoets5380]

Can you do my kenwood km x1000 stereo amps a rebuild i have 2 of them 😊

[@dublegi-hr8kq]

Those things in the VU meter are not servos. They are normal analog VU meters with mirrors attached to the coils. Nice work, and nice equipment. One suggestion, I think the videos would be enriched if you went a little bit into explaining the electronic circuit designs and how they work (like they apparently do in that manual you showed).

[@PrimeHiFi]

Yeah, I misspoke when I called them servos. Thanks for the kind comments and I will take your suggestion into consideration!

[@paulpaulzadeh6172]

Nice, but I got dizzy , too much camera movement

[@PrimeHiFi]

It’s a video after all

[@stillastillsfan]

What solder do you use?

[@stillastillsfan]

Ok I got to the point in the video where you mentioned the solder you use. Thank you. Outstanding work.

[@Roudaki677]

I have one that can use some TLC, it was working fine but it’s been parked for a few years, would you be interested and how can I contact you?

[@PrimeHiFi]

You can reach me via email on my KZbin page. I’m not currently taking in work though. Will be some time before I continue.

[@JIMISPIER]

Designed by engineers for engineers.

[@bonemealmc]

:D