Why do i hear a thud when i shut down the system?

HI, System--audio researh classic 60 and preamp sp15,triangle celius speaker and two vandersteen sub woofers. THANKS.

maxhammer412-21-2011 12:47am

jtinn Details Discussions Posts This discussion Message User 1,124 posts 12-21-2011 at 01:35am Copy Comment URL Report Comment Edit Delete turn off the amp first and wait a few minutes then turn off the preamp.
uru975 Details Discussions Posts This discussion Message User 684 posts 12-21-2011 at 01:43am Copy Comment URL Report Comment Edit Delete If you turnoff the preamp before the amp, that could be the cause. Generally you turn on source, preamp(s) amp and turn off amp, preamp(s), source.
amthanh Details Discussions Posts This discussion Message User 34 posts 12-21-2011 at 02:37am Copy Comment URL Report Comment Edit Delete As you mentioned your system has 2 sub woofers, I think the thud comes from your sub, it could happen when you turn off your system even with the amp first because the sub still connect to the pre-amp output. Try to turn off the sub first and see what's happen.
philjolet Details Discussions Posts This discussion Message User 2,306 posts 12-21-2011 at 04:04am Copy Comment URL Report Comment Edit Delete if I remember right, it is a capacitor(s) discharging
rrog Details Discussions Posts This discussion Message User 1,958 posts 12-21-2011 at 06:34am Copy Comment URL Report Comment Edit Delete I have owned Vandersteen subwoofers with an Audio Research Classic 60 and never had a turn off thump. Amthanh, Vandersteen subwoofers do not connect to the preamp out. They connect to the outputs on the amplifier.