After talking to an old friend it turns out the 7550 was the amp he set 3 pairs of Bose 501 speakers on fire with. Burned up the crossovers twice and returned them but the third time the manager said no way so my friend took them home and built his own crossovers and never had another problem.To do the job it's meant to do it must have some bulletproof protection circuits in it.
Unlike the infamous "Phase Linear" 350 and 700 Watt amplifiers of the 80s. Our nickname for that one was the "Flame Linear".
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