Re: Thoughts about amplifiers at 3/4 volume.
The main thing affected by reducing gain (moderately) at that point in a system is to attenuate output noise from the console and any noise picked up in the wiring. Since this noise is fixed, and you are now using a hotter send to get the same output, the effective S/N is improved.
The trade-off or different philosophies are;
a) throttle back the amp for lowest noise floor, often done in churches to manage noise floor in quiet ambient spaces. Of course if carried to excess you can limit maximum amplifier power output,
b) WFO (rock and roll setting), preferred for live music to insure that the amplifier will deliver full power, and if clip limiting is routinely engaged, WFO gives you the most limit range or headroom, before the audio path saturates upstream.
Both valid for different end goals.
JR
PS: As an amplifier product manager I have often pondered removing the gain trim (they cost money), but customers want them even if they don't use them much.
