[McPanse]

During peak passages of some music, mostly female vocals, I'm getting a slight distortion -- a little static burst, like my headphones are clipping off the higher frequencies.

It's like a little sizzle or low-volume static popping up momentarily when the music peaks.

I've done the obvious trouble shooting, removing and swapping components to isolate the culprit. No luck.

For example:
Pioneer DVD>7.2 DAC>TC-754 switch>Little Dot MKIV>DT-880 = yes
Pioneer DVD>7.2 DAC>TC-754 switch>Little Dot MKIV>Grado SR-60s = yes
Pioneer DVD>7.2 DAC>Little Dot MKIV> DT-880s and SR-60s = yes
Pioneer DVD> Little Dot MKIV> DT-880 and SR-60= yes
Pioneer DVD>7.2 DAC> headphones = yes
Denon DVD2910>Little Dot MKIV> headphones = yes
Denond DVD2910>Denon A/V receiver> DT-880 = yes

For all these test, I used the same track, "Dante's Prayer" off Loreena McKennitt's Book of Secret. Between 2:20 an 2:40, shortly after the lead vocals come in is where the peak sizzle thing is worst.

Anybody experience anything like this? Any idea what to do about it?

I've even turned off my Airport Express wireless device on the chance it was RF interference.

It's really getting on my nerves.

 

[gp_hebert]

Have you considered the obvious - the recording itself?

 

[McPanse]

Yes. While I did my "testing" using that one track, I'm finding the problem with a variety of recordings, mostly female vocals.

 

[jellojoe]

ground loop?

 

[McPanse]

I've got everything plugged into the same strip. Doesn't ground loop produce a constant buzz or hum? I get clean sound expect when certain passages peak.