Just finished my 2.1 C4S & Imp switch kits and need some advice on how to diagnose some static/popping/hissing that I'm getting strictly in the left channel of my headphones. Using the 32ohm setting with HiFiMAN planars.
The problem did NOT exist when I finished the stock build, so I know it should be limited to the upgrades. The problem didn't follow the tube after a swap, so it's the circuit and not the tubes. Tried switching to balanced using a speaker taps-->4pinXLR, and nothing changed, so thinking it seems like nothing to do with the output re-wirings. Tested the different impedance levels, none of which have made a dramatic difference, though I THINK the static got just slightly quieter on the lower settings.
I have taken a thorough look at what I think is every joint I soldered for the upgrades and re-flowed more than a few wherever they looked like they could use it, and still no change, so I think I'm now down to a bad component.
The only thing that could be more demoralizing at this point would be to start uninstalling & checking resistors & whatnot only to still not find the source, so I need a little direction from somebody as to what the most likely culprit might be. From the descriptions in the manual, seems like it's going to be a resistor, but there's 2, maybe 3 of the associated sounds described there instead of just one, so I really don't know.