im interested in hearing any input for short term and long range power for my wilsons.i currently own an audio research sp6a pre and a bryston 4b.there is a krell fpb 300 here but i have been advised by one of the guys to wait for a 600.there is ,i read that a potential problem with direct coupled pre's and krells exists that caused more than a few to blow up.i cannot buy a new amp and a new pre at once. there is a pair of pass labs 600 mono blocs out there that look interesting.any ideas............................the price range is around 4 5 k us used