6550c, as I recall, the Nola Vipers I heard were paired with Cary equipment. Both amp & preamp were tubed. It's been too long to remember the models, although I think the preamp was the slp98. As to "speakers I think are better." what's the point? I freely admit that I've not heard enough good speakers in good rooms to make any claims to being a good guide to the myriad of products out there. At the time, I'd been looking for a speaker to replace my Magneplanar 1.6 and I was visiting those audio dealers who had products of interest to me. As I recall, I was listening to various Von Schweikert, Gallo, Usher, and Nola speaker systems. Just so you know my preferences and prejudices, I have no interest in audio reproduction that tends towards audiophile hyped up detail or tonal exaggeration. I suppose the primary thing that I like is a sense of musical palpability for lack of better term. The sense of real instruments vibrating in a definable space. The Nola Vipers, in that room with that equipment, as well as every other speaker I heard that day(except for the Nola References) failed that test for me. The system I'm listening to now has that ability to give a musically palpable impression in spades, so I've not done too much further auditioning since. BTW, I did go back and listen again to these speakers and the same impressions persisted. All this said, it's obvious from reviews that some listeners had a different impression of the Vipers and that's too be expected. It just takes some luck and work too get the right equipment synergy with every speaker it seems. FWIW, Reference Vipers pop up now and then for 6-7k on this site.