I have a power-off thump on my Dension DH-201 / DMP3A (hard disk based MP3 player head unit). I've heard of power-on thumps on amps before but until Googling I hadn't haer of thumps on power-off but it look slike it is just as much of a common problem. It doesn't always happen and ususlly turning the vlume to zero before switching off seems to prevent it, but I'm looking for (a) a good explanation of what causes it and (b) a cure. So far I've seen people talking on teh net about using relays to isolate the speakers during power up and power down, which would be relatively easy to do using the electric aerial signal wire driving a pair of DPDT relays through a transistor fed from the +12v line. Another possible cause for power on thump I've read about is that the amp has been built without blocking capacitors in series but I'm not 100% sure whether this wouls also stop the thump on power off. Any thoughts?