SocProf, after the inputs, and up to any output, everything in the DP machines resides within the digital domain. What Phil is saying is basically, when you put something into the analog input and it's converted to digital, from there it's like a Y cable to the SD card and monitor system in parallel. The recorded signal is exactly like what's being monitored because there is only a single conversion process and signal pathway. There are a few possibilities such as perhaps a Guitar insert effect that was set on Play instead of Rec, and when de-assigned made the track sound significantly different. If all things are equal and it does sound different on the playback, something is definitely wrong. But digital systems tend to fail rather completely as opposed to analog systems, where for example, a capacitor in the audio path will start to fail and the audio still passes through it, but it really sounds bad. I'm stumped. Mainly because even if some component was going bad, why would it sound bad only on playback?