Pass Labs X600.5 or a Pair of Classe Omicron's?

Doc, there is no upgrade possible for the Pass LabsX-600's to the new generation .5 series. I believe that the 600's were the best sounding of all the X-generation amps, but the new X-.5 series is a significant change/improvement compared with the first generation X-series. If you can get a pair of 600's for that amount of money, it would be a great addition to the sonics of your system. I have heard the Classe amps in a couple of different systems, but can't be helpful regarding if their is a significant sonic difference them and the PassX-600's because it was not an audition in my own system. In my system for years I used Transparent cabling, went through a long period of auditioning over five different cable companies wires and finally decided on Acoustic Zen IC's and speaker wire. It's all personnal taste and system synergy, but I believe the Acoustic Zen wires are significantly better then any of the Transparent stuff and very reasonable priced. I have a review of the new Acoustic Zen Absolute reference here on the Gon that you might find helpful. Hope this helps.

Sorry Doc, I thought you mean't by up-grading the 600's to 600.5 was an actual modification that could be done by Pass Labs, not the trade-in deal offered by Audio-Logic in Iowa. To answer your question, no I did not find the 600's "dry", but not as "warm/musical" as the Aleph 1's mono-blocks in my system. I would suggest you might try auditioning a 350.5 in your system, which I think sounds better then the 600's, and still would save you another $3000.00 in total cost. Unless you need that much power, I drive MG-20R's in large room and have all the current I need, its a beautiful sounding amp that has the "warmth/musicality" of the Aleph series with the dynamics/details of the X series.