I have a D150 that I bought in late 1970s.
I had amp refurbished in 1981 by Remcron (in Canada) and upgraded to D150A with IOC added and the gain pots moved to front with new faceplate.
I haven't used this amp for about 6 years. It is boxed and stored. I was considering setting it up again as small system in the den.
I have noticed that shortly after amp is powered off, there is a low frequency thump heard on both channels.
Is this normal? Is there a fix for it?
My main system includes a pair of DC300A-II, each running bridged mono mode.