RK097 channel imbalance

[Ace o' Spades]

Today I found out something a bit surprising...my PIMETA's volume control (ALPS RK097) has a very noticable channel imbalance near the lowest point that you can turn it. The left channel gets louder than the right channel and then quickly evens out, but it is still annoying. Is this typical in RK097s or did I get a defective one?

 

[tangent]

I wouldn't say "typical", but it is common, yes. All pots can do this, which is why they're specified to have a certain channel matching only down to a certain point. Errors build up over the pot's travel range, so that no pot manufacturer tries to specify channel matching over the entire range.

If you find yourself using that lower end of the range often, consider lowering the gain of your amp. You'll get better noise performance as a bonus.

 

[Ace o' Spades]

I would consider it but I am probably going to get some HD580s later on. Thanks for the info, BTW you and morsel have a very nice amp here

 

[IEATTEFLON]

I have 5 amps using these pots with this problem. At the lowest setting the right side always comes in first. Even at unity gain its rather bothersome when I want to listen to music at very low volumes.

 

[Ace o' Spades]

^Okay, good to know that this is a pretty universal thing and not an isolated case

 

[tangent]

If you're regularly spending time down at low volumes and you don't need the higher ranges despite having lowered the amp's gain to unity, the next step I'd take is to increase the value of R1, to as high as R2's value. You can lower the amp's gain to 0.5 this way -- or anything in between, with lower values of R1. The disadvantage of this method is that the noise will go up as the R values do. That's why I say don't make R1 any higher than R2, even though technically you can.

Another option is to put a resistor inline with the left and right output wires. (Not R8. This is different.) If it's equal to your headphones' impedance, you again get a halving of the voltage swing. The potential problem here is that you will change the sound of the headphones, and it might be for the worse. Some headphones are said to improve in sound when doing this, however, so it's worth a try.

Finally, you could always buy new, more voltage-hungry headphones.