Originally posted by GooseYArd
Without knowing the output voltage of your pickup, it's hard to say why that might be. I'm assuming that you tried it with the input attenuation on the amp turned all the way up (down?), if not, that'll probably do it, if your preamp can exceed the input sensitivity of the amp. I'm not an electrical engineer, so I could be oblivious to the effect of the amps input impedance on the instruments output. It's pretty precise work and hard to do with your ears, especially if you're worried about damaging your speakers and err on the side of caution by using the amps attenuator.
Since the power amp is not going to give you any indication that it is getting close to clipping (it's just either clipping or not clipping), then without knowing the nominal outlevel of the pickups/preamp, its difficult without a meter or an oscilloscope to see how close to clipping it is and to get your gains balanced. Car audio guys are geniuses at this and have all that junk at their disposal.
Doing it this way probably seems like an academic excercise to most people, but its pretty cool that the power amplifiers that many of us use are actually precision instruments who's behavior can be predicted very accurately as long as all the quantities are known. Jeez I'm rambling![]()
Yes, I had the volume control on the power amp maxed out when I plugged my bass in direct. The PLX's have indicator lights for "Signal", "-20db", "-10db", and "Clip" levels. I had to hit the stings pretty hard to get the -20db indicator to light up (with my bass fully cranked).
[I probably need to talk to Bob Lee (QSC) to make sure my amp is doing what it should be doing with that type of input level.]
And really... toupe's just don't seem to belong in the Metal scene