My Revox B 760 tuner fix up project

Discussion in 'Tuners' started by w1jim, May 13, 2017.

  1. w1jim

    w1jim I can fix it but good... Subscriber

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    I picked up a really cool Revox B-760 (I know, cool and Revox is redundant) that needed a little love.

    Problem #1 was that the tenths digit on the display would show 0 & 8 instead of 0 & 5.
    The driver chip was an 9317BPC (no cross reference found). I looked through the data sheets and decided that an SN74LS47 would do the trick.
    After pulling out the suspect IC I installed a socket just in case I was wrong (yeah, that's happened) and installed the replacement.
    After reassembly it worked!

    Next problem is that the signal strength meter doesn't work.
    I poked around (and recapped) the logic board but have yet to locate the problem - I'm thinking it's either the meter movement or the driver transistor. I also used some deoxit on the adjustment pot.

    Finally I recapped the audio board - replacing all of the tantalum with audio grade Nichicon electrolytic.

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  2. w1jim

    w1jim I can fix it but good... Subscriber

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    The audio board - before and after:

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  3. w1jim

    w1jim I can fix it but good... Subscriber

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    Nudies:

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  4. w1jim

    w1jim I can fix it but good... Subscriber

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    And some glamour shots, along with another project; good thing the Revox is built like a tank since the Sansui ain't no light weight!


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    nedseg likes this.
  5. Raynald

    Raynald AK Subscriber Subscriber

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    That is beautiful, good work fixing it up.
     
  6. w1jim

    w1jim I can fix it but good... Subscriber

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    Wow - after much research on a replacement signal strength meter I got it to work with just some simple tapping!
    Mad skills here.

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  7. Raynald

    Raynald AK Subscriber Subscriber

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    Must have sourced their meters from the same supplier as Luxman, I had a T-110 that required the same 'fix"!
     
  8. w1jim

    w1jim I can fix it but good... Subscriber

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    I think there was some foreign gunk in the movement and tapping dislodged it.
    Prior to that I used a powerful magnet to nudge the pointer - that probably helped to break it loose.
     
  9. jblnut

    jblnut Don't Overthink It Subscriber

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    Nice work as always Jim ! That is a very serious looking tuner for sure. Although the Sansui is screaming out to be sitting on a TU-X1 :)

    jblnut
     
  10. w1jim

    w1jim I can fix it but good... Subscriber

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    Oh, I know - or even a TU-9900.
    I'm thinking of bringing this set up to the FrankenFest - if my back can hold out.
     

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