Hi Peter,
Just a couple of quick things to check/try on the computer side.
1) In audiomidi setup, check to see what the balance levels for each channel of the dac are set for.
2) if your dac will support it, try integer mode in PureMusic -- this disables most processing and the dithered volume control as well, not to menion that it also can take the dac's performance up quite a bit.
What dac do you have -- these numbers look just too low, even for something like a modified squeezebox or other 1 v max output voltage dac.
Do you have the mute checkbox checked on the front screen of PM, or possibly the replay gain feature turned on -- this can read info from the metadata file for each track and adjust the volume accordingly.
Also, if these are simplistic questions, please pardon them as I really have no idea how familiar you are with all of this.
Like others have sai, it sounds either like a dac problem, or very possibly a PureMusic/audiomidi configuration issue.
Offhand I don't know the output level of an i-device, but I think they are 1v or a little less. Do you have a line out dock cable that you can use instead of the headphone out connection? These usually give a much better output signal than the headphone output sends.
HTH,
Jim
Jim Rebman -- recovering audiophile
Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).
s.e.x. 2.1 under construction. Want list: Stereomour II
All ICs homemade (speaker and power next)
