I have never purchased a seperate amp for myself (although I've installed 5 channel amps for others), but that was fairly straightforward. I am curious about the Parasound New Classic Model 275 and 2125; they are compact, have impressive specs and good reviews as well.
Now these have posts for two sets of speakers on the back speaker selector buttons on the front. Is it possible to drive a 4 ohm pair (fronts) with an 8 ohm pair (rears), or do I need to get seperate amps for each set of speakers? If it is possible, will switching the front buttons on/off during play be dangereous?
What are you driving? If they are fairly efficient and easy to drive, you may not need to spend the extra $200 for the 2125. The extra 25 watts and 5 amps of current will be pretty well inaudible unless you have difficult speakers.
You should be able to drive both 4 and 8 ohm speakers concurrently without problem as long as those 4ohm speaks don't dip too low and you don't try to have a house party with all four blazing along. That's an interesting question tho and I'd contact Parasound or AudioAdvisor with your speaker specs first before buying. BTW, yes you can switch without damage.