the brown sound comes from a too low voltage in the powersupply which gives you this saggy feel (recto does it with spongy/bold), not from the low bias. EVH is not the reason for the low bias
the low bias is artificually recreating the effects of voltage vs. current over a PSU voltage drop. The ratio of voltage to current is not linear and therefor as you were to lower the voltage to the PSU the current would drop at a higher rate. The effect of a voltage drop would result in the amp having a lower wattage than it was designed for, that lower wattage is a result of of a lower current compared to the voltage (as the formula for power is P=VxI). The result of having tubes not operating at their intended rating they go into crossover distortion, the by product of the tube not having enough current to faithfully power the signal. That was what EVH purpously did with his Marshall's but as a result was burning shit out and had to lug around with him a variac PSU. When he went to peavey, they diesinged a circuit that would recreate the inhereted voltage drop.
Don't believe me refer back to the formula P=VxI, drop the voltage and see what happens to the power, even if the current were to stay static and not change, the power would drop, but realistically when you drop the voltage the current will also drop, considering you have resistance in the circuit, the ratio of resistance and voltage is the result of the current. With both the voltage droping, resulting tin the current drop, the power dissipation would be severly lowered, just like the negative bias voltage applied to the supressor grid, bottom line the output power of the tube is lowered, meaning, it is not getting enough power to reproduce the sound without coloration, this coloration is crossover distortion or the "Brown Sound".
you were close though, the brown sound is a result of an output power drop, not a voltage drop, exactly how you get that power drop does not matter.
I should note, I am going for my Associates in Computer and Electronics Engineering Technology, so this stuff is extremely fresh in my brain right now, so I am not just some snot nosed know it all punk talking out of my ass from shit that I have read and tried to translate over the internet to correct people and be a complete ass.
They did other stupid shit like placing 300v 5w rated resistors in a circuit that contained 500v and near 15w of power, thats why you can blow shit up when tubes fail. I think they did that on purpuse so you 1) couldn't bias the amp hotter without getting into trouble (a that's what you get for fucking with shit" attitude and with dude like roger crimm, just proved that was peavey's attitude towards people who biased the amp) and 2) so the amp would prematurely fail with small fortune repairs (50-150 USD not including replacement tubes)
