The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Dynaco VTA tube amp kits, all Tubes4hifi.com products and all Dynakitparts.com products


    VTA ST-70 BOM question

    Share

    BruceB

    Posts : 5
    Join date : 2009-03-03

    VTA ST-70 BOM question

    Post by BruceB on Mon Mar 23, 2009 8:42 pm

    Finally got around to ordering parts for the board, and got an obsolete/unavailable from Mouser on the six trim pots. Any specific things I should watch out for on a substitute?

    I found some Bourns that are single turn, cermet, 10%, 1/2 watt, blah blah blah... but they are only rated 300V.

    Bruce

    Bob Latino
    Admin

    Posts : 2413
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA ST-70 BOM question

    Post by Bob Latino on Tue Mar 24, 2009 7:51 am

    Bruce,

    If you are using the VTA driver board > the four DC bias controls are Mouser PN 594-63P503. You can use for the 10K AC balance controls Mouser PN 594-63P103T7. These controls see very little voltage - less than 100 volts.

    Bob

    BruceB

    Posts : 5
    Join date : 2009-03-03

    Re: VTA ST-70 BOM question

    Post by BruceB on Tue Mar 24, 2009 6:28 pm

    In that case, I can use the Bourns pots. They have the top adjust and not the side, which would be pretty interesting to use on the VTA board.

    I ordered this style:
    652-3386R-1-103LF

    Bob Latino
    Admin

    Posts : 2413
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA ST-70 BOM question

    Post by Bob Latino on Tue Mar 24, 2009 6:55 pm

    Bruce,

    I could be wrong here BUT > I believe you have ordered the wrong part? The Bourns "3386-R" has the pins in a line. I think what you want is the "3386-P" which has the correct triangular shaped pin alignment for the VTA driver board. See photo below.

    Bob



    BruceB

    Posts : 5
    Join date : 2009-03-03

    Re: VTA ST-70 BOM question

    Post by BruceB on Tue Mar 24, 2009 8:27 pm

    Wouldn't be the first time, lol, and you are so right. I can be creative and make them work until I can replace them.

    I guess it's better to find out now before they arrive (they've already shipped)

    tubes4hifi
    Admin

    Posts : 1292
    Join date : 2008-11-30

    DC bias and AC balance pots for VTA70 PCB

    Post by tubes4hifi on Sat Mar 28, 2009 9:27 pm

    the correct part to use is Bourns 3386P or equivilent
    Mouser has them
    652-3386P-1-503LF
    652-3386P-1-103LF

    Sponsored content

    Re: VTA ST-70 BOM question

    Post by Sponsored content Today at 5:59 pm


      Current date/time is Thu Dec 08, 2016 5:59 pm