Reducing power output of an amp?

[dmm128]

I just built a ruby amp and was wondering if there is a way to reduce the power output.  I know Roland puts a power squeezer on there amps but I don't know how its done.  I am looking for the amp to break up at a lower volume.

[raulgrell]

With the ruby, perhaps it would be a better idea to add a (switchable?) distortion stage and a master volume control...

[petemoore]

I just built a ruby amp and was wondering if there is a way to reduce the power output. 
1 Reduce the power input, instead of 9vdc, try 7vdc supply.
2 Use a less effecient speaker [may sound different].
I know Roland puts a power squeezer on there amps but I don't know how its done.
  I am looking for the amp to break up at a lower volume.
  Dropping the input voltage = lowers headroom = breaks up at lower volume.

[GibsonGM]

Essentially, Pete's talking about VVR for the Ruby, lol. Variable Voltage Regulator.  Just use an adjustable supply voltage, and as he says, off you go....they do this on larger amps as "power scaling"....

[petemoore]

  LM317 Voltage Regulator.
  Beware the Radio Shack pin#/letter re-code and write the pinout under a drawing of the chip, then double check it.