Just acquired this beast of an amp here and need schematics for it. Looks like some parts may have been replaced by previous tech and may not be original. Mostly problems are in the power supply areas. Also, there seems to be a RED LED in the middle of the board that is undocumented in the users manual. Anyone know what its for? This amp is HUGE! Anyone with experiences with these in terms of sound quality? Any help is appreciated, thanks.