Per JohnK; I'd agree; if you try SET do it right. Matching the speakers to the amps are absolutely critical with low-powered SET - don't bother with those 89db sensitivity Merlins if that's what you are considering. The combination does not sound compatible unless all your listening is done below 75db or so (beyond that you're likely to get distortions you won't enjoy). OTOH, if you are looking at higher powered SET options, such as those using tubes in parallel or perhaps even those using 845 tubes in the output stage you might squeak by and like what you hear with your Merlins. I don't know your other gear to tell you with any authority how it may differ, but I'd speculate given only experience with low-powered SET and some exposure to the higher powered SET options. At it's best SET amplification seems to render the most holographic sound staging I've ever heard. The midrange is astounding giving a whole new meaning to "presence". Vocals sound particularly natural. Actually, "natural" is a very good descriptor where SET is concerned. Where it lacks traditionally is in a tight low-end. I'd imagine that in the realms of the level of gear you'd be considering you'll be sacrificing less down there, but I'd still speculate that your CAT would perform better in lows and highs (more so in the former), while I'd guess the SET (paired off with the right speakers) would excel in midrange magic and soundstaging abilities. What kinds of music do you listen to mostly? If you are into music with lots of vast dynamic shifts and slam, I think you'd be better served with the alternative. SET would not be my choice to listen to Symphonic scale music, or rock if I listened to that (dense music with great complexity). For vocals, intimate music, chamber music, acoustic stuff...more simple arrangements and those which feature vocals, SET is just wonderful, and certainly worth your consideration.
Marco
