LM1875 Amp layout

Suggested wiring
 

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OK. Maybe just a pot bypass switch then, no need for additional input RCAs.

Are there preferred switches for this application?

Any good quality switch will do, nothing spectacular. You'll have to think how it'll fit in your front/back panel wherever you decide it goes.

If you can find a jack socket with 2 pole 2 throw switches, you could get it to switch over and disable volume automatically ;) wiring will be the same, but they must be fully separate switches!

e.g. 10pcs 3.5mm Audio Jack 5 contacts 3 conductors for TRS stereo plug through hole right angle with additional switch DPDT 2P2T|Connectors| - AliExpress
 

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Last edited:
Correction!!
I now believe that the issue is due to a circuit problem that is overcome by increased voltage or current as a result of turning the pot, nothing to do with the actual pot.

Same issue with the new pot and no such issue with another amp and different speakers using the same source

There is either a high impedance/resistance joint in the amp, or in the speaker connections, that is overcome with increased volume.

I have an issue in my car with the same symptoms and I think it is caused by the manufacturer using very fine connecting pins in the connector in the door jam. Even though they are gold plated, the surface area is minuscule and I think affected by the smallest amount of corrosion or poor connection.

I would would welcome any suggestions while I try to work it out.
Cheers