CAT SL MKIII vs ARC SP 11 or 10

Put the CATs Ultimate aside (since I have not heard), I would probably choose ARC SP11 MKII for my setup. There are only 6 tubes (3 for phono and 3 for line stage) in SP11 MKII so the tube cost is relatively cheap.
Depends on match up, the CATS is definitely more opaque than ARC. In my opinion, the CATS is less musical to my ears. However, either one should be a good choice.

These comments are interesting. Years ago some felt the SP 10 was more musically involving than the SP 11, as the SP 11 moved toward more accuracy. Especially in the phono stage, the SP 11 wasn't as bloomy or euphoric. Some of the comments here now are the CAT Ultimate falls flat musically because it isn't as musical as an SP 10. I spent years with an SP 11 and now I've had the CAT Ultimate for a few years. With the CAT it's easier to hear the difference from one recording to the next because it colors the sound less. It exposes more information, good and bad, than the older ARC units rather than wrapping the sound in a euphoric coloration.

Speaking from years of experience Jld1965 should go one of two ways. If the phono stage is all he's going to use he should go with the SP 10 if he's looking for the "golden glow" sound. If the line stage is of material significance, go with the CAT Ultimate or MK 3. The SP11 doesn't have as good a line stage as the CAT and if a euphoric phono stage is what he wants why stop halfway?

Buy gear to enjoy the music! Not to tell which recording is better or worse. That's engineer's boss' job! We are music lover aren't we?

Bombaywalla and Egrady yes, the 10 is euphonic and a bit more than real but what is really telling is that my heart ALWAYS enjoys if my brain is telling me something different.

So far as the CAT is concerned, yes it is murder on tubes, noisy and all that but said and done it is really a nice piece. Excellent line and phono stage. The noise is what is bothersome to me, and the tubes, does it burn through those 12au7's!! Interestingly on this topic Anthony Cordesman did a comparison of these 3 preamps in a 1986 issue of Stereophile that I just revisited, a review of the CAT. His conclusion was quite the same as the comments here with the 10 being the more colored, the CAT being closer to the 11 but the 11 reigning as the SOTA at that time. "If you own a 10 DON'T be so hasty to trade it."

It isn't quite so easy, is it? I can't bring myself to sell the CAT. Maybe I'll try that upgrade Bombaywalla.

Tubegroover -- I never had noise from my CAT, nor did I change tubes for 2 1/2yrs (OK, that's not so long). Maybe that upgrade is indeed in order?!