I have these I.C.'s between my preamp and amp.Yes,they are a silver/copper hybrid.I cant say I have really put them up against anything other than the P.B.J.'s they replaced but they sure kicked the P.B.J.'s butt which they should.I considered the improvement I got with the H.T.huge! Very clear but relaxed presentation.Very smooth and detailed.They dont sound too thrilling for a few hours.At about 30 hours they really opened up but I think they continued to improve up to around 400 hours.