I've bought a few (8 or 9) Sundown amps for the last years. I had one single problem recently with a NS-1 v1 : it was covered by the warranty, I sent the amp back and now I received the v2. Two friends of mine bought Crescendo amps : one 5500 is fried, and a 3500 had problems too (on 3 amps). Maybe it was some users errors, maybe it was bad luck ! They bought those for the price ! I won't judge the quality of those amps with my little experience, but it doesn't make me want to try CT products !