STC-3A Volume Pot Issue

[thefitz]

Hello all,

I'm new 'round here and looked for info on this topic but couldn't find any.

I recently installed a pair of ASB2-5 pickups on my bass along with an STC-3A preamp. I installed them myself (uh oh!!), and wired them in 18V, which I read was possible.

I have a very strange issue now, where the volume knob doesn't work. The 3-band EQ works fine; the pickup blend works fine; even the push-pull slap contour on the volume knob works fine. The volume knob doesn't do anything - turning it down doesn't change the volume, but I do hear a slight (ground-like) buzz whenever I turn the knob.

Looking in the control cavity, everything looks fine - it's a giant mess of wires, anyway. Would anybody happen to know what's wrong? I find it strange that the volume knob itself is the only thing that doesn't work, and I'm getting full signal and full functionality otherwise.

I'm in love with the sound of these pickups, and actually don't mind if the volume knob never works - but I'd like to know what I did wrong!

 

[thefitz]

Re: STC-3A Volume Pot Issue

I realize I may have put this in the wrong forum!

Mods, feel free to move this to wherever is appropriate!!

 

[Funkfingers]

Re: STC-3A Volume Pot Issue

Look at the volume pot. Ignore the DPDT switch contacts for a moment. You should see two white wires and one black wire going to the three "pot" terminals.

I just looked at an STC-2p kit that I have in storage. The relevant connection is MISSING on my EQ rig. It might also be missing on yours.

Around the chassis edge of the pot, you should find the legend T(symbol)15A 10k and some digits. To the left of the digits should be a solder joint with two black wires.

Probably missing from that location is a third black cable, a short run to the volume pot terminal.