Balance Control Pot solution?

[Jock Strap]

Restoring vintage HiFi amps usually involves replacing the Balance Pot? Unfortunately, these centre-detent pots that provide zero resistance in the centre position are virtually unobtainable.

I had an idea... how about using a many-way, make-before-break, 2-pole switch instead? A suitable array of resistors to provide stepped attenuation of each channel would keep the control without losing all of its functionality?

It's an expensive solution so I have not yet tried this but I wondered if anyone else had used such a solution. The method I have used so far is to replace the pot with two resistors to effectively remove it from the circuit. I then leave the pot in place but not connected to retain the appearance.

 

[WobblySam]

It's an expensive solution so I have not yet tried this but I wondered if anyone else had used such a solution. The method I have used so far is to replace the pot with two resistors to effectively remove it from the circuit. I then leave the pot in place but not connected to retain the appearance.

I've run into this in the past year or so and after searching, I did the two resistor fix.
I see what you're saying regarding a stepped balance, but it would seem that more than a two pole switch would be required since you still need that 4th leg that's on a balance pot. I haven't really thought through it, but the concept seems sound.

Good luck with the project.

 

[fred soop]

Excellent idea. Some amplifiers have used stepped attenuators for volume control and McIntosh used stepped attenuators for tone controls. The downside is that rotary switches are EXTREMELY expensive, especially 2 pole, 24 or 36 position for a volume control. A balance control could probably have fewer steps.