First off, my rig: BOSS LS-2 side 1: Sansamp RPM>EHX Bass Big Muff>Digitech Whammy BOSS LS-2 side 2: Sansamp RBI>Human Gear Animato then the bass (either my Geddy, or my American Stanard. I can even replicate it without an instrument plugged in, so that's not the issue either.) and this all goes to a MOTU 828MK3 converter, which goes to my iMac. My issue is that it seems that if I have just a bit too much treble (as far as the rig is considered, and not my ears, mind you) if I stop playing, I get a high pitched squeal. It'll go away, or decrease in pitch at the least if I: 1. Turn down the high end on anything, even slightly. 2. It will also go away, depending on the nature of whatever else is affecting it, if I turn the tone down on my bass. This is most evident if the Big Muff or Animato (especially sensitive, it seems) are on, though I can also have it show up if just the sansamps are cranked. I've heard of the LS-2 giving off a squeal, from one reviewer. Could that be it? Thanks!! This has always happened, even before the converter was installed, so that's not an issue. I'm also using headphones, so it's not feeding back to any speakers, either.