Matt I don't know Acid all that well, but it's a cousin to Sound Forge so many of the setup option should be the same. Verify your selection of inputs in the Windows mixer (sndvol32.exe) - it might be set to MIC rather than LINE in (I am assuing you use either an integrated sound circut of a standard PC sound card. Some cards/onboards include their own mixers eg: Delta cards) The other end is the inpout assigned to Acid itself. In SF that is from the Options menu to Preferences, then tthe Wave tab where choicse for both Recording and Playback are made. I have no problem running my bass into my Boss LM-2B limiter pedal then the pedal output to my LINE in and recording in Sound Forge; the levels are a bit low but I can use the software to compensate