I had this problem before, and thought it was because I was using unbalanced cable. But now I've gone and bought a TRS 1/4" to XLR cable and the noise problem remains. Feel free to download this file using the first link, or stream it with the second: http://uploadfile2.putfile.com/getfi...4421314213.mp3 http://media.putfile.com/Reamp-Test 0:00 (first third) - live performance (no noise) 0:11 (second third) - reamped performance (tons of noise!) 0:22 (last third) - the direct guitar signal recorded via DI (no noise) My chain is as follows... my guitar is going into the instrument input of the DI, DI goes out to amp (this in/out is parallel to the instrument in), also XLR out (on the other side of the transformer in the DI) to line input on my Presonus Firepod (level at 100%). The amp was recorded into the Firepod with an SM57. The first and last thirds of the clip were recorded at the same time. Then I switched the XLR/TRS from the line in to the 'cue mix line out' on the back of the Firepod. This meant while playing back the DI'd guitar, it would feed out to the amp. This is where a ton of noise is introduced. The noise ONLY happens when the cable is plugged into the Firepod (otherwise the amp is silent, except for the usual hiss associated with not having a guitar plugged in). The noise is also there regardless of whether I am PLAYING the DI'd guitar back or not, so the problem is not in the recording part, but in being plugged into the Firepod. I also have an XLR/TS cable and the problem exists when using that too. I have tried using different outputs on the Firepod, the cue mix line out works the 'best'. Any ideas?