Hunting some noise gremlins in my setup.
PC USB audo card (soundblaster g1) via 3.5mm to RCA to Eris E3.5 = no problem, very clean
PC USB audio card (soundblaster g1) via 3.5mm to Sub8 to Eris E3.5 via RCA cable = electrical noise made worse by mouse movement?
Tried a few different cables, isolating power and input device cables, even ferrite cores (desperation)... no difference. USB bus/motherboard to blame? Maybe the RCA cable? Switch to TRS between Sub and E3.5s?