CAT SL MKIII vs ARC SP 11 or 10

I had an SP 11mk2 and a VT100mk2. I replaced the SP11 with a CAT Ultimate. The CAT has a few quirks, the power supply hard wired to the control unit and a volume control lacking in flexibility, but it's sound was a step up. The bass is fuller and tighter. The soundstage is bigger and more percise. The SP 11 is a fine unit and I don't mean to suggest it isn't a good choice. However, it is more colored than the CAT Ultimate. In some systems the SP 11 may be a better fit, but the CAT is more tranparent to the source.

Well, I have a CAT SL1 Sig Mk3 & I really love it. The phono stage is really quiet, dynamic & produces some really good music.
My friend has a ARC SP-6A. Once Richard Gray (of RGPC) brought it up to spec & K & K Audio changed the coupling caps to Kimber + changed the power supply caps to Panasonics + changed the RCA output jacks to Vampire + added an IEC, the SP-6A sounded very good in my system as well. The bass of the SP-6A is not as deep & controlled as the CAT, the CAT has better high freq extension. However the SP-6A has that ARC signature midrange that has bloom that I have not heard in any other product.
I like the CAT better while my friend likes the SP-6A better!
IMHO, you cannot go wrong with any of your listed choices.
I have read many times that maintenance of tubes in the SP-10 & SP-11 is expensive. Each time the owners tried to save money buying less expensive tubes they felt that they had wasted their money (sound degradation) & that they should have paid the extra money for those expensive tubes. No personal experience - just telling you what I have read.
Search the archives of Audiogon & AA. FWIW.

CAT Ultimate or SL1 Sig. Add to the comments above, the CAT offers very good dynamics. Also drives difficult loads beautifully. True, it's more on the "neutral" side than the ARC.

If you want classic tube sound and a great phono stage (OK line stage, but the phono is the real reason to buy it), you should consider the SP-10. If you'd rather have more neutrality and frequency extension, the CAT is likely the ticket for you. All of the choices you listed are fine performers, it just depends on what sound you're looking for.

Howdy,

Let me be a bit of a contrarian here. I have owned (and listed in order of preference) the SP 10, SP 11 and CAT Ultimate. To my ears, the CAT is the most dead piece of equipment I’ve ever heard. That thing was dull, opaque, sterile and lifeless. “Neutral” maybe, but it did not begin to capture the essence of music. I had the SP 11 at the time I bought the CAT and tried for quite a while to convince myself that the CAT was an improvement. Finally, I put the SP 11 back into the system and did a direct comparison. The CAT was listed here on Audiogon the next day.

I bought my SP 10 after that episode and sold off the 11. I lived happily for about a year at which time I began to get interested in digital. Up to this point, I had use primarily analogue sources. The main short coming of the 10 is it’s line stage. It’s not that the line stage is bad, it’s that you have to take the 10 out of by pass mode to access it which in turn puts all of the front panel clap-trap in the circuit. This definitely degrades the sound. Since I had gotten fairly serious about adding a decent digital source, I debated whether or not to send the 10 to Great Northern Sound for modification or to look elsewhere. In the end, I bought the Herron line and phono stages and sold off the 10. I have lived fairly content with these for the last couple of years.

As a footnote, I had a chance to hear a Friends 10 a couple of weeks ago and there is still something very special about that pre-amp. It makes music like none other I’ve heard. It has a liveliness that I’ve not heard elsewhere. It might have something to do with the two 6L6’s in the power supply. I am hopeful that the Aesthetix combo (that I should get to hear in the next couple of weeks ) will combine the best of the 10 and Herrons in one package. This may be my final resting ground for a pre-amp.

Regards,

Scott