Thanks, Alan. I suppose what's puzzling us is the difference in volume between, for instance, the signal of a cd player fed into the PM16 and the signal of the pre outs fed into the PM16 -- and this made me wonder if the signal coming from the SR6004's pre outs is supposed to be relatively weak? (Since, in the most common scenario, you would use a power amplifier to amplify the signal?)
Also, if this is true -- does that mean we're making the PM16 work harder/use up more watts/generate more heat by feeding it the pre outs' signal?
I realize we could take the PM16 out of the chain entirely and the SR6004 would likely drive the fronts, center and surrounds without issue -- but it's such a nice, solid, old-fashioned integrated amp that it seems worth keeping it around even if it's for purely sentimental reasons.