I can not find my manual for the Boss ME-25, but I do own one, and a Digitech Guitar Effects Box also and found that one. All of them to me are the same. They all are a recording device only with an aux input (mini-plug - 1/8" for plugging in a playback device say from the computer). But in Sonar for each track you wish to record on, you have to set up the input to the track and the output for the track. I use a audio/interface so the ASIO drivers become the input - like left, right, or stereo for each track to record on. The output I usually put to Master for each track for Sonar to mix down with before sending it back out to a audio/interface or say a sound card in the computer. The aux mini-jack on the ME-25 would be like playing a *.mp3 file from the computer sounding out to the sound card and taking a cord and hooking up to the aux input of the ME-25 to say listen to a recording while play ing along with it. But only the guitar plugged in to the ME-25 is going to come out of it and be able to record into the computer with. There are not sound synths (soft synths) in it, just tones and sounds to change a little with pre-sets for distortion, or reverb or wah, or phazers or whatever effects for the guitar sound instead of the plain -ol' straight guitar. If anything they are only one-way recording devices and not a playback device unless outputting from a sound card or audio/interface into the ME-25 in the first place. Just like new synths have an input to play a *.mp3 file or wave file perhaps into a synth but it does not output the sound again to record with only the synth output sound of the patch of the synth. It sounds like the problem you are having is setting up the tracks in Sonar to record on. There are separate inputs and outputs for each track to set before arming the track to record on, and the volume is only handled by the ME-25 volume pedal, except on my Digitech (same type unit) even full down on the pedal probably won't overdrive the input into the computer and any volume changes like a volume pedal on my synth will not be moved much to change the volume into the computer and Sonar recording software.