Sony TA-F6B Resto

Discussion in 'Solid State' started by thefragger, Apr 19, 2008.

  1. thefragger

    thefragger Certified Crazy. Subscriber

    Sony TA-F6B Resto... Lots of Pictures!

    This is my fixer-upper. I bought it on eBay a couple months back as a complete parts-only unit. The guy described it looking much worse ('badly scratched face,' 'rusted top,' etc...) that what it actually is (little bit of rust on top, maybe one scratch a half-inch long); I think it looks great! Being in my graduating year, I never had much time to work on it.

    What I did do was find that a thermal fuse had opened and replacing that brought the amp to life! Since then it's been sitting...

    ... Until now. I'm a stamped-and-certified Mechanical Engineering Technologist! So today I took to tearing that amp down. It's pretty filthy inside and I think at some point something tried to build a nest under the amplification circuit. It's bad.

    My plan is to tear everything out, hose everything down, clean out the interior rust, patch up the top panel rust, and do a full TOTL recap. Polish the casing to a lustrous shine and plant it at the centre of my system.

    This will be my biggest project in a long while (too long), my pride and joy.

    I figure I'll update this thread as a work log. Wish me luck!
  2. thefragger

    thefragger Certified Crazy. Subscriber

    These photos are from today's teardown.

    First the nudie,

    Slowly breaking it down on my 'bench,'

    Amp board out, literally an 1/8" of dust,

    Water seepage?

    Dinged up heatsink...
  3. tri-comp

    tri-comp Well-Known Member

    The one thermal fuse in this amp. is in the soft-start circuit.
    Strange that it would blow as it's only used for a couple of seconds until the switched-mode power-supply is up and running. Then it's shorted out by a relay. Check that relay in any case!
    I think that you should have a look at the schematic's. PM me with your e-mail address for a free pdf-copy.

    A sound advice would be to ABSOLUTELY DO A RECAP of the switched-mode power-supply.
    I had a lot of 'fun' with something similar in a TA-N86 / Class-A amp. until I finally did the full re-cap.
    TA-N86 ->


  4. Stoffie

    Stoffie Sony afficionado

    Yep, definitely a good idea to recap the PLPS with 105C caps...

    I have four amps with PLPS' waiting for such a treatment.

    Good luck! Nice amp btw! Reminds me of the TA-F7B I have, also 1cm of dust and crap inside, water leakage etc... but it is shining now!
  5. thefragger

    thefragger Certified Crazy. Subscriber

    Get this-- there is no relay. Dr*Audio told me the same thing, but the PCB has no relay on it, nor does it look like one was ever installed. I'll get you my email address, but I've bought the service manual already.


    That's the plan! When I was testing it after replacing that thermal fuse the sound would work for a while then fade away after about an hour. I'm hoping that the full re-cap will fix that.

    Cheers tri-comp.

    P.S. That TA-N86 is a pretty sweet looking amp!!
  6. thefragger

    thefragger Certified Crazy. Subscriber

    What if I can't find / get / afford high-frequency caps for the power supply? Would regular low-impedance work in a pinch, or is it blasphemy?

  7. thefragger

    thefragger Certified Crazy. Subscriber

    Alright, I've completely disembodied the electronics and I'm left with a very dirty, dusty, and rusty chassis. I've started to sand down the rust and I'm left with shiny, bare metal. I really, really don't want it to rust again, at least not for another 30 years. What should I use to seal up the bare metal?

    I'll try and get some photos up. Tomorrow.

  8. thefragger

    thefragger Certified Crazy. Subscriber

    I picked up the capacitors from Purolator yesterday and got to work into the wee hours of the morning.

    Took lots of photos. Will post later.

    Enjoying the fruits right now. Really really warm sound. Neil Young's in the other room calling me back.

  9. thefragger

    thefragger Certified Crazy. Subscriber

    Black Pastic Rivet Replacements

    [​IMG] [​IMG] [​IMG]

    New Caps (twice the amount that I needed)


    PLPS Before, in Progress, and After

    [​IMG] [​IMG] [​IMG]
  10. thefragger

    thefragger Certified Crazy. Subscriber

    Amp Before, In Progress, and After (the size difference is really, really noticeable)

    [​IMG] [​IMG] [​IMG] [​IMG]

    Old vs. New

    [​IMG] [​IMG]

    Old Parts


    Amp in, PLPS in, and All Hooked Up

    [​IMG] [​IMG] [​IMG]
  11. thefragger

    thefragger Certified Crazy. Subscriber

    Making Some Noise

    [​IMG] [​IMG]

    Very Shiney


    Corrosion (?? how can I remedy this?)

    [​IMG] [​IMG]

    Need to Re-Paint the Lettering


    Looking Good and Making Itself Known

    [​IMG] [​IMG] [​IMG]
  12. Stoffie

    Stoffie Sony afficionado

    Very nice work! It's been a lengthy process, but seems like it was worth it!

    Will be doing the same to my TA-F7B soon, when the parts arrive. Already took care of the switches and pots in the preamp, so a recap is all that is left.
  13. legal eagle

    legal eagle Sound Hound

    Nicely done.
    I've always wanted one of those, as that's BY FAR the best looking integrated i've seen. There's quite a lot of those in Europe, but they are pricey, and another integrated will probably push the wife over the edge...:yes:
  14. rsfmotoman

    rsfmotoman Super Member

    Nice Work!

    That has to be a very satisfying feeling to bring an amp back to life. All I can is resurrect speakers.

    Fine job!
  15. westend

    westend Audiopile Subscriber

    Nice job. For lght corrosion I use a dilute solution of Phosphoric acid, sold as water softener cleaner or Martin Senour Iron Etch.
    Now the caveats: This acid reacts with aluminum and especially anodized aluminum very fast. You have to dilute it and always try an inconspicuous area to test (back of faceplate?). If you don't know anything about chemicals and metal etching, don't bother trying. Your newly rehabed Sony will end up with a lot of wierd stains. Rinse with water after the treatment and keep it away from the meter lenses.
    I watched too much "Watch Mr. Wizard" on TV as a kid :D and have a couple of years of college chemistry and 20+ years of autobody and shipboard painting experience so I kinda know what I'm doing with preparation chemicals. It's not for the faint of heart but will remove oxidation from nearly all metals.

    Remember: If you use this you're working with Acid. It will burn your skin and irritate your eyes and lungs. Use precautions.
  16. thefragger

    thefragger Certified Crazy. Subscriber

    Thank you!

    I can't wait to see it!

    Hahaa. I work on a one-in-one-out basis. This amp and that Mitsu tuner have moved in, so I'm selling my Akai 2600 amp and tuner. It also helps me cover costs of the resto.

    Thank you! I'm working on rehabing a pair of JBL L36's. It's pretty much the same thing as fixing up an amp, except more elbow grease, a little more electrical knowledge, and patience. I found the blown thermal fuse by checking all the wire connections and working through one-by-one for continuity. This was my first restoration of this magnitude ever, and I'm a strong believer of jumping into something that you want to learn how to do.

    I still have to swap out the front--end caps and do more tests. I've already got the replacement filter and power caps, but the lead spacing doesn't match and the replacements are MUCH smaller than the current ones. I'll have to come up with an intermediate circuit board rather than having the caps floating in the air supported by their leads. It doesn't that also one pair of caps are snap-in leads :no:

    Yikes. I love chemicals, assuming that this is corrosion. I've never seen aluminum corrode like this before.

    But I'm leaning towards anodized aluminum-- there are some scratches on top of the face that cut right through the anodized layer :thumbsdn: and the colour underneath is right for aluminum. I have no idea about the knobs. They could be aluminum too, they're pretty hefty, but they're solid (so it makes sense).

    Hell, I could always whip up a batch and test it on the backside as per your suggestion. What kind of reaction should I be expecting if this is anodized aluminum?

    Thank again for the comments! Love AK!

  17. thefragger

    thefragger Certified Crazy. Subscriber

    Well, it's been seven months now and I'm still wowed by this amp. Really, really great music coming out of this thing. Next up is a swap out of the power supply caps!

    Once I get this Yamaha amp offa my bench first...
  18. bwfan

    bwfan New Member

    TA-F6B is one of the best integrated amps that I have heard. I got into collecting amps about a year ago, internet research pointed to Kenwood, Pioneer and Sansui. I bought TA-F6B on ebay because it seemed like a really good deal. When I hooked it up for testing the music sounded so sweet that I played it at 12'o'clock for about 5 hours. And then it suddenly quit working, it turned out to be the thermal fuse in the power supply, before PLPS, that tanked. I ended up buying one more TA-F6B in as is condition, and it won't power up. it turned out to be a bad solder joint in PLPS, and it works fine too. Just one question, on both my TA-F6Bs, it seems that when balance control is turned completely towards either side, there is still some sound, albeit very little on the other channel. I wonder if thats the normal behavior for this amp. Can someone else who has access to TA-F6B test their amp, at moderate loudness and see if there is significant crosstalk. Hopefully, someone will come back to this old thread...
  19. thefragger

    thefragger Certified Crazy. Subscriber

    WOW! You own TWO?! :banana: :banana: :banana:

    That thermal fuse and a popped cap in the PLPS were the problems in mine. Fixed them and it made some noise, replaced all the caps and it sings oh so sweet now.

    I could check that crosstalk issue for you tomorrow, family sleeping right now, thought it doesn't surprise me because all the wires are run side by side through the amp.

    Pleasure to meet another owner and welcome to AK!

  20. highfigh

    highfigh Well-Known Member

    Are you sure it's corrosion, or is it mineral deposits? If it's the latter, use vinegar. I had the same kind of stuff on the ST-A7B I sold last year and I knew that if I used a strong cleaner, it would screw up the anodizing and possibly the silk screened lettering. Then, I remembered what we used to get mineral deposits off of boats and bought some plain, white vinegar. It looked better than ever. It looked like the day it was unpacked for the first time and having worked for a Sony dealer, I unpacked a heck of a lot of their equipment.

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