Got my TX-SR875 should I bridge or Bi-Amp

Bridging puts a lot of stress on most amps. I would also agree with Bi-Amp.
Ben

Dannie, a still better option might be neither of the above. The 875 is a quite powerful amplifier and lab tests have measured it at over 150 watts into 8 ohms. For most uses it has more than enough maximum power capacity in its standard form, and you shouldn't assume that it would be inadequate for you.

If the unlikely situation developed that a higher maximum power capacity was in fact needed, then your only effective option with the 875 would be bridging. The so-called "biamping" feature that the 875 and some other receivers advertise is a misnomer. Biamping requires two separate amplifiers(as the term implies)and a separate external crossover before the amplifiers so that they're only amplifying the required part of the frequency spectrum. A receiver has only one main power supply section and sending its voltage to a speaker through two sets of output transistors(one set previously unused for back surround speakers)rather than one can't double the available power, as some imagine, or increase it by any amount.

Bridging, on the other hand uses an entirely different process to send two voltages(but of opposite polarity)into the one set of speaker input terminals so that in effect while one voltage pushes, the other pulls the speaker driver in the same direction and they co-operate. Following Ohm's Law, power is proportional to the square of the voltage, so with perfect efficiency in the process the power output would theoretically be quadrupled when double the voltage was sent into the speaker by bridging. In practice, the power can be roughly tripled. Another effect is that although obviously bridging an amplifier can't change the internal impedance of a speaker, the doubling of voltage also doubles the current required(Ohm's Law again)at a given impedance.

So again, you're highly likely to have all you need right now, so relax and enjoy the great sound.