Why can't you connect two amplifier sections in either parralel or in series just as you can connect speakers? I'm sure talking about amps here. To use an analogy, you put 1.5 Volt batteries in series and you get 3 Volts. To run them in parralel will give you 1.5 Volts, but the resistance will be 1/R+1/R instead of R+R in the case of batteries in series. The current for a parralel bridge will be voltage divided by resistance which will be higher. So I don't see the point in bridging in series, which will void the whole purpose of trying to get more current in the first place.

Kuan