Yesterday I bought a used Gain Cell DAC and plugged it into my system, and ran into a problem with it.
The thing is that there was clear distortion when I used either toslink/optical or s/pdif/digital coaxial. (tried both)
Via analogue input there were no problems at all. (Input 1, 2 or 3)
This means that when running strictly analog, there is no issues at all, but when using the digital entrances, there was clearly distorsion from the left channel.
This morning I started by connecting my headphones to the Gain Cell DAC out of curiosity.
The sound was clear and without distortion.
After this I booted up my whole rig and suddenly the distortion was gone.
I have no explanation to the problem, but something suggests that the Gain Cell DAC has an on/off problem.
I will however try again later today after work, as it might be a periodic problem.
I have heard that a few other persons in the past, also have had problems with the left side when running digitally and they had to have a kind of replacement.