[cody69]

I'm wiring a passive volume pot to a TPA3110 and puzzled about the connections. The pot is a 50K Stereo taper https://www.parts-express.com/50k-audio-taper-stereo-potentiometer-1-4-shaft--023-650. The PE tech told me the connections are 1&4=Ground; 2&5=wiper; 3&6=input source.

I've test-wired the unit, and it behaves backwards -- max volume is counter-clockwise and no volume at max clockwise position. I'd appreciate any advice to straighten this out.

I have pins 2&5 connected to the inputs on the TPA3110 board, pins 3&6 connected to the DAC output via a 3.5mm mini-jack. The ground pins 1&4 are connected to the ground on the 3.5mm mini jack.

I am thinking either the connections are wrong on the pot, or more likely, I don't have a ground from the 3.5mm jack. The chassis is wood, so there's no real ground in the unit. Power is coming from a spare laptop power supply, which I'm not sure provides a ground either. Is a true electrical ground (via house 110v ground) needed to ground the signal grounds and volume pot ground?

[Davey]

Easy fix.

If the pot is working backwards you need to reverse the connections on the outside tabs.

The center tabs (wipers) are your output to the following TPA3110 board.  Sounds like you have those correct.

Dave.

[cody69]

If the pot is working backwards you need to reverse the connections on the outside tabs.

Yes, this is easy to do, thank you.

My concern is a function of not understanding the difference between signal vs power grounding, if and when they're different. And I've read if the pot isn't grounded correctly it acts as a simple rheostat vs a potentiometer, which I didn't want to occur.

[Davey]

You do have the ground successfully connected otherwise you wouldn't be able to achieve zero volume.  If the ground were floating or not connected correctly and the pot functioning as a rheostat you'd still hear volume at minimum rotation.

Make sense?

Dave.

[cody69]

You do have the ground successfully connected otherwise you wouldn't be able to achieve zero volume.  If the ground were floating or not connected correctly and the pot functioning as a rheostat you'd still hear volume at minimum rotation.

Make sense?

Makes sense. I switched the leads as you suggested and the volume pot works correctly.
You've been helpful Dave - thanks again.