VTA ST-70 BOM question

BruceB · 1 VTA ST-70 BOM question on Mon Mar 23, 2009 8:42 pm

BruceB

Posts: 5
Join date: 2009-03-04

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 · 2 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 7:51 am

Bob Latino

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Join date: 2008-11-27
Location: Massachusetts

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 · 3 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 6:28 pm

BruceB

Posts: 5
Join date: 2009-03-04

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 · 4 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 6:55 pm

Bob Latino

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Posts: 249
Join date: 2008-11-27
Location: Massachusetts

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 · 5 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 8:27 pm

BruceB

Posts: 5
Join date: 2009-03-04

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 · 6 DC bias and AC balance pots for VTA70 PCB on Sat Mar 28, 2009 9:27 pm

tubes4hifi

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Posts: 41
Join date: 2008-11-30

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

1 VTA ST-70 BOM question on Mon Mar 23, 2009 8:42 pm

BruceB

2 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 7:51 am

Bob Latino

3 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 6:28 pm

BruceB

4 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 6:55 pm

Bob Latino

5 Re: VTA ST-70 BOM question on Tue Mar 24, 2009 8:27 pm

BruceB

6 DC bias and AC balance pots for VTA70 PCB on Sat Mar 28, 2009 9:27 pm

tubes4hifi