TR75 Interpretation Help needed!

[CapeCanaveralGal]

I need some help! After searching vainly thru WWW & forums, I realized I'm not the only one unsure what the "labels" on the face of the TR75 (an other higher end TRs) mean/do. I have a nice TR7 and its very straight forward and simple (it has knobs for distortion, bass, treble, depth and speed). I needed more wattage and found this TR75 on e-Bay but it's rather confusing.

So, across the face of the TR75, from right to left are upper and lower inputs (number 1 and 2), then the following knobs: volume (duh - I know this one), bass, treble, and effects (huh?, there is an input in the back for effects in/out - is this what that knob controls?); then, there's an input for "stereo," (I have no idea about this...can a single guitar go into the stereo in? If so, does that give me access to the knobs (esp. "effects" and "presence") on both sides of this input?) anyway, to continue my recitation...from the stereo input, there are another set of upper and lower inputs (numbered 1 & 2), then another row of knobs: distort (which tends to reduce the volume but still has that Ricky growl I love so much), bass (another, presumably for inputs on this (left) side of the amp), "mid" (?), treble (another,again presumably for inputs on this (left) side), then there's a knob labeled "presence" (this one's a real mystery to me...is this for reverb??), then there's another volume knob and the toggle for on (which has 2 positions, does this mean only one speaker is active if its on in that direction? Obviously, I'm cyphering some of the more obvious ones, but it would really be nice to have someone familiar with this amp clue me in. There's 2 pre amp in/outs on the back and I really don't know how to use these, but it'd be great to get the depth and speed effects off my TR7 through this amp (as well as some of the effects off my little VOX or Roland). I found a footswitch pedal on e-Bay with 2 switches on it, would this enable switching between the pre amps?? Do the inputs upper and lower do different things?? There's no manuals for these things to be found anywhere, so this would probably be the next best thing if these questions get answered here. Any help you can give me I'm most grateful for - Thanks ya'll!