Yamaha T-2 mini overhaul

Discussion in 'Yamaha' started by Mr. Yamaha, Sep 14, 2017.

  1. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

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    My T-2 needed some work because the power switch was creating a loud pop through the speakers when turned on and when turned off. It seems to be the power switch.

    While I was in there, I saw some leaking caps with corroded legs, so I decided to give the T-2 a mini overhaul.

    Including:
    • Replacement of all caps (all Nichicon KZ, FG and ES).
    • Replacement of the 3 rectifier diodes.
    • Upgrade the power switch to a Triac solution.
    • Resolder all connections.
    • Replace the fuses.
    • Cleaning of the switches.
    So far I took out all boards which will be worked on and started with the caps.

    More updates soon!

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    Last edited: Oct 11, 2017
  2. avionic

    avionic " Black Knights " Subscriber

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    :lurk:
     
    Last edited: Sep 14, 2017
  3. avionic

    avionic " Black Knights " Subscriber

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    Well,if you read it on the internet It must be true.:rolleyes:.Not very reliable...This gear is 30-35 years + old and still working. I'd say that they are very reliable.
     
    Last edited: Sep 14, 2017
  4. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

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    :p

    So, not preventive replacing those?

    And what about the 2SD476A's? Are they more reliable than the 2SD234's?
     
  5. avionic

    avionic " Black Knights " Subscriber

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    When I rebuild burnt up channels in the M series amplifiers.Which I do quite a few of. It is not due to the diodes failing . But to shorted output transistors and uncontrolled B+/- stressing them to the point of failure .I've had way more zeners smoke than 1S1555's. Its just quicker for me to replace a pulled OEM diode with a new one with long leads, rather than try and fiddle with short stubby leads.That and personal piece of mind. Because of stressed circuitry. I know they have been subjected to voltages they weren't meant to be subjected to.
     
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  6. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

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    Made some progress this weekend. The main board and the upper digital board are done. I must say, I'm pretty happy with the looks of the Nichicon KZ / FG's.

    All 'lytic caps and the rectifiers are replaced, all solder joints are renewed and all components which were awry placed, are re seated. Afterwards the boards were cleaned.

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  7. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    Very neat work :thumbsup:, that is one serious tuner, l have read good things about the T-2 but l have never heard one or seen the internals before. Looking forward to hearing how you think it sounds when you are done.
     
  8. Oilmaster

    Oilmaster Ozzy Subscriber

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    Your kitchen seems as spotless as your PCbs ;)
     
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  9. llwhtt

    llwhtt Super Member

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    That's a very small cat!
     
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  10. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    Haha, l was going to say the same thing, is the cat very small or is that a very large pcb. The cat looks like it is checking out one of the new large Nichicon UFG's :rolleyes:.
     
  11. llwhtt

    llwhtt Super Member

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    Mouse size cat for getting into mouse holes.
     
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  12. Oilmaster

    Oilmaster Ozzy Subscriber

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    And that why there is a dedicated thread "cats on audio gear" on AK

    miauw
     
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  13. MannyE

    MannyE Exterminate! Subscriber

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    Beautiful work!
     
  14. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

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    Yeah, it really sounds great. Let's hope it still does (or better) when it's finished :biggrin:

    Best thread on AK!

    Thx!
     
  15. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    If it already sounded great it will be interesting to see what gains you have made.
     
  16. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

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    Finished this baby last weekend. She sings again. And no pop anymore when turned on or off. Due to the caps or due to the Triac switch? I guess we'll never know :idea:

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    Last edited: Oct 10, 2017
  17. Mark B

    Mark B Yamaha Fan Subscriber

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  18. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

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    Very nice, looks great ;).
     
  19. 39cross

    39cross AK Subscriber Subscriber

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    Are those rectifiers at the bottom of your photo of the replaced caps? or something else?

    I'd be curious to see a photo of how you wired the switch if you have one.
     
  20. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

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    Yes, those are the rectifiers. Sorry, I did not take a picture of the triac switch. I mounted it on the frame behind the transformer.
     

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