Hmm. I can reproduce it with a plain kernel and while in "home" mode, by plugging those values into an unused preset. And I can hear it just as clearly.

However when I record it to a WAV file through the PC's Line input and view the wave in CoolEdit, I can't actually see any clipped peaks. I can clearly HEAR what sounds like clipping distortion even when previewing the WAV in CoolEdit, but I can't SEE it in the waveform.

And now suddenly I'm not so sure that it's in the player at all. Although it distorts on every other piece of equipment I've got (car system regardless of amp gain setting, home system regardless of volume level, computer line input regardless of input level, more than one pair of headphones including ones that have never distorted on any material before and which were plugged straight into the player), there was one case where it didn't distort.

That was via the MICROPHONE input on my PC. It didn't distort on the microphone input when I turned off the gain boost. And I can crank the PC's volume up really really loud while it's using the mic input, and it sounds GREAT. Whereas, with the line input (and every other possible audio output including my car system), it distorts even at very low volumes or amp gain settings.

But you're not supposed to plug line-outs into a Mic input. It's a different impedance. Odd.

What is it about the PC's mic input that would make it change the way the player's output stage behaves in this situation? Did the mic input place a higher "load" on the line outputs or something?

I'm confused.