Hi. I have this amp on the bench, it was just very dirty, not used for a long time, dirty pots, in short, things like that. Adjusting the idle current as specified in the manual, 15 minutes of warm-up, between 7 and 15mV, so far, all good. The problem is that if I leave it operating with load and sine wave with the heat sink hot, the quiescent current drops to zero and as it cools down it returns to the preset value. Is that okay? It has happened to me with other amplifiers, but it never drops to zero.