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    help needed with Sound Values #957003 board

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    Antonn

    Posts : 2
    Join date : 2019-03-11

    help needed with Sound Values #957003 board Empty help needed with Sound Values #957003 board

    Post by Antonn on Sun Mar 22, 2020 4:53 pm

    Hello all, I was given a basket case ST70 that came with the Sound Values PC-3 6GH8 board #957003)and the SDS cap board. I have re-cased the amp and all was good until I went to test it with a preamp/cd, It was working for a short time until R26 on the board started smoking.
    I have found the manual for the Sound Values PC-3 in question and see that there was to be a 10 ohm resistor (page2 task 7) installed with the input socket? Is this a separate 10 ohm resistor than what is on the board. Can someone that has the board installed confirm where this 10 ohm resistor goes..if needed at all?
    Or am I wrong in assuming that?

    Thank you
    Tony
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    stewdan

    Posts : 207
    Join date : 2010-03-07
    Age : 81
    Location : Houston Texas

    help needed with Sound Values #957003 board Empty Sound Values Board

    Post by stewdan on Mon Mar 23, 2020 2:18 pm

    Hi Tony, I dont have any expertise with the SV Board for the ST70.

    But for what it is worth, there is one for sale up on the E-Site.  It includes the installation documentation.


    eBay item number:
    223455712256

    If you do a ebay search by item number, it should come up.

    Stew
    tubes4hifi
    tubes4hifi
    Admin

    Posts : 1650
    Join date : 2008-11-30

    help needed with Sound Values #957003 board Empty Re: help needed with Sound Values #957003 board

    Post by tubes4hifi on Thu Mar 26, 2020 7:55 pm

    no reason at all for the 10 ohm resistor to smoke, unless it causing a short to something else.
    It's likely the same exact 10 ohm resistor used on the original ST70, one from each channel ground to the stereo-mono switch.
    Original ST70 manual can be downloaded from my DOWNLOADS page
    http://www.tubes4hifi.com/downloads.htm
    There was also a 10 ohm resistor from the PCB to the front octal sockets, maybe you have it connected to your bias test points????

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    help needed with Sound Values #957003 board Empty Re: help needed with Sound Values #957003 board

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