[Menisk]

I've just built my Mini3 and I'm having a serious problem with crosstalk that I can't track down. I'm measuring 3.6k of resistance between the left and right output. I also get 3.6k between pin 1 and 7 of U4 so it has to be after the opamp in the circuit.

I've poked around a bit with a meter but I cannot for the life of me work out what the problem is.

Anyone have ideas or things to suggest I test?

 

[amb]

The resistance measurement is normal, because you're simply measuring the path:
OL -> L1L -> R4L -> R3L -> IG -> R3R -> R4R -> L1R -> OR
Since the path goes through ground it's not contributing to any real crosstalk.

Check your OG and IG solder joints at the input/output jacks, as well as the ground solder connections at the volume pot. Also try a different source and another pair of headphones, maybe there is something wrong with the interconnect wiring or plugs.

 

[Menisk]

Thanks for your help Ti. I've worked out that the issue is to do with an impedence adaptor I built for my Etymotic ER4s. Nothing wrong with the amp at all. I should've tried other headphones, not thinking right. Problem is fixed and the amp is sounding great. Thanks for taking the time to design it.