@hasmarto By any chance did you have the REL subwoofer that is listed in your system description connected to the 255se at speaker-level? And if so were you connecting the ground (black) wire from the sub to a negative output terminal of the amp?
If so, since the balanced amp has a full amplitude signal on its negative output terminal I’m guessing that the damage might have resulted from the combination of supplying the amp with balanced power via the 1800 and the fact that the full amplitude signal on one of the amp’s negative output terminals would have been connected to AC safety ground via some presumably low impedance in the sub. I can’t fully explain that, but that’s my hunch if the sub was connected as I’ve described.
Good luck. Regards,
-- Al
If so, since the balanced amp has a full amplitude signal on its negative output terminal I’m guessing that the damage might have resulted from the combination of supplying the amp with balanced power via the 1800 and the fact that the full amplitude signal on one of the amp’s negative output terminals would have been connected to AC safety ground via some presumably low impedance in the sub. I can’t fully explain that, but that’s my hunch if the sub was connected as I’ve described.
Good luck. Regards,
-- Al