When I turn the SVT2 non pro to ON, and wait a minute or two,then take it off standby a weird almost rushing wind/ ocean sound is emmited from the speakers...After about 10 minutes it goes away.. I thought it may be a preamp tube.. But then I tried and wiggled the 12AU7 driver and it made that noise.. So i cleaned the socket and pins on the tube and reset the tube... sound goes away.. but it may also be heated up by then. i am thinking. if i wait 2-3 hours and turn it on again it does not do it.. but if I wait overnight it does.. I turned the amp on today it did the same whoooshing/ static/ like a river rushing sound for about 5 minutes and then slowly disapated.. I also thought that it may be condensation somewhere in the chasis but i am at a loss..