Sansui 6500 Volume/Balance Pot

Discussion in 'Exclusively Sansui' started by surfnsound, Jan 13, 2018 at 4:26 PM.

  1. surfnsound

    surfnsound Active Member

    Messages:
    104
    Hi all, need your help here. I got myself a AU-6500 but its not in good physical shape. The previous owner has exchanged volume and loudness pots, which are working now, but loudness is not working. The soldering job does not look very clean neither.

    I think I want to replace bother and redo the connections.
    1. What would be a good replacement for part 1010580, 250k? The current pots for volume and balance are both stereo with 3 tabs each. Do I need 4 tabs? What are the original connections?
    2. What are the original cable connections, colours, cable routing from the F-2036 board to the volume and balance pots?
    3. Not important but nice: The plastic covers on the on/off switches (mute, loudness, ..) as well as all buttons are in bad shape. Any source would be appreciated.
    Here is the current situation....

    Balance pot

    IMG_0330 (1).JPG

    Balance pot and volume pot en top

    IMG_0332.JPG

    I have access to the schematics but again, I can't determine the original cable routings. Any photos or explanations of the original situation would be appreciated...

    Thanks, this baby plays nice but would love to restore it to original with loudness.

    Cheers,
    David
     
    Last edited: Jan 14, 2018 at 6:41 AM
  2. _mano

    _mano Active Member

    Messages:
    414
    Location:
    London, UK
    Hi David,
    The 1010570 is still available from Sansui-parts. Looking at the parts list, it states both volume and Balance are the same, which I think is an error.
    Usually, for Loudness to work, the 4th tab on the volume Pot, injects the Loudness into the Volume Pot. If the Pot is round then it will be a separate tab at the opposite end of the 3 terminals.
    The Balance, could be the same, with the 4th Tab being connected in a such a way to give the balance, effect as per the diagram.
    May me another member who has worked on the 6500 can clear up on the parts you need and the colours of wires etc..
    Mano
    ps.. cant see the pics

    1010570 is the Baance
    1010580 is the Volume Pot
     
    Last edited: Jan 14, 2018 at 4:48 AM
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  3. surfnsound

    surfnsound Active Member

    Messages:
    104
    Hi Mano, thanks, pics are now uploaded, always have sharing problems with google photos.

    According to the AU-6500 manual both pots are 1010580. THe 1010570 posted on Sansui parts does not have the loudness tap. I do not find a 1010580 on Sansui-parts and neither on ebay. That's why I though using new alps.. maybe with a PCB for easier soldering.
    If any of you might have a picture or two from the AU-6500 to see whether the original cables go that would help.
     

    Attached Files:

  4. _mano

    _mano Active Member

    Messages:
    414
    Location:
    London, UK
    Hi David,
    I have used the ALPS blue pot as a replacement for the Volume Pot and also to retain the Loudness function. Yes you can use a PCB or solder direct to the Alps pins and then onto the existing leads or to the F2036 board. The 1010570, I would suspect is the Japanese Balance control implementation at that time. ie.. when the Balance control is at the middle, the signal there is no resistance in the signal path. When you turn the Balance to the left, for example, the Left channel volume remains the same, while the right signal is attenuated.
    I ended up making a replacement for one of these out of dual 36 step rotary switch as these are not available new.
    If you are novice to this technology, I would wait for another members who have actually worked on the 6500 to give you further help to progress this.
     
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  5. surfnsound

    surfnsound Active Member

    Messages:
    104
    Hi Manu, thanks, I ordered the blue APLS with loudness tap for volume And another blue alps for balance (but indeed there is resistance on both sides...). In the manual the say 250k (M,N). Ordered an MN250k just in case as well.

    Now connections...

    Balance: On the schema I think I see the balance VR701 and VR70. I think I can figure out the cables based on these schematics.

    Volume: But I do not see the master VR703 and VR704, the volume. I think they just might be "in the fold" (they not on the next page neither. Hello AU-6500 owners;....Maybe somebody has another schematic? Or can make a pic of the cabling?

    vol.png
     

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