The 212R has two 8 ohm, 50W, 12 inch SD speakers in parallel, resulting in a 4 ohm total impedance. So yes, if you unplug one of them, it will deliver half the output sound power.
The only thing I don't understand is why would you want that - can't you use the volume knob to do that?
it only sounds real good if you crank the master volume up and then the overall sound is just too loud for the stage... I really would like a power soak/attenuator to achieve this. But dunno how to build on really...see? the amp sounds crap with the master vol down low.. Am wondering, if I did detach one of the speakers would it not damage the output transformer?
No, it's a transistor amplifier. The speakers are wired in series (I think), i.e. left speaker wire's connect to right speaker then right speaker up into the amp. Am trying to make it more of a 50w output rather than 100w... your info is great... Think I'll go pull some wires off...
Me too. If it's a vacuum tube amp and the speakers are in parallel, disconnecting one speaker will increase the output impedance lightening the load on the amp. If there is an 8 ohm output tape use it.
Solid state amps do not generally use output transformers. A higher impedance load will simply pull less power from the amp.
If you are going to try using a resistor, something like 8 ohm at 50 watts should work. It should be a non-inductive resistor.
If this amp has a direct out from the power amp section, connect it to a smaller speaker, this is often done in studios when people want a more overdriven sound at a lower volume, or simply buy a small amp, they are as cheap as chips these days...but as someone else has said, I don't understand why you can't overdrive the power-amp from the pre-amp section ? or is it specifically speaker coloration you're after ?