CAT or VAC for Shahinian Obelsik

Hi Sam,

I am going to listen to a JL-2 on Monday June 5th. Even though
I am not planning on a return to Vac amps at this time, the dealer also has the Auricle 160 monos in his showroom. I may or may not get to hear the Vacs, but would be happy to report my findings to you. the Cat is a mark 1, but if all goes well
I expect to get the Mark 2 sigs.. I did own the Vac 220 Sig monos and although I did not find them to be deficient in their power rating, I expect the Cat to be capable of driving
more speakers. FYI, I will be driving Vandy 5a speakers.

The CAt has hi bias (it's class partly/mostly?). It should be able to drive most modern speakers (i.e. +88 db spl)perfectly well.
That said, I don't know the vac or the new obelisks (if any different). A pair of old ones sounded fine driven by a jl2 -- not very balanced (positioning) but that wasn't the cat's fault.

Sam,
as a fellow owner of both Obelisks and Diapasons, let me say a word of caution. I have found that the advice to use powerful SS amps, which can deliver a lot of current, to be correct, especially with the Obelisks. In my experience only SS like Densen, Naim or Plinius gets the Obelisks to deliver the strong, well defined bass they are capable of. A friend of mine, who lived in the same house and has Obelisks as well, bought a tupe amp which delivered close to 100 watts - it coul d not cope with the Obelisks. Nor could the McIntosh MA6500 integrated I first used. So be careful and make sure you have listened at least to one of the recommended combinations before you settle on a tube amp. Over on
http://groups.yahoo.com/group/shahinianspeakerowners/
you may do a little search, the subject was discussed at lenght there.

powerful ss

Thanks for the responses. I know that people have found SS works. My thought was that the CAT JL2 is a different tube animal, that wattage doesn't tell the whole story - it's how stable the amp remains under difficult load. What I've heard is that the CAT is quite stable and may be more so than many SS amps. Any thoughts? Gregm - you heard an actual JL2/Obelisk combo? Very interesting. Any other description of how that worked? Thanks again for everyone's responses.
Sam

With all due respect to Hassel, the CAT is not your average tube amp. Not all tube amps control speakers the same. 100 tube watts does not necessarily equal 100 tube watts. But the same holds true between ss amps.

The JL-2 is conservatively rated at 100 wpc. With 8 6550 tubes per channel driven in Class A, and a power supply design and output transformer that is more massive than an entire Naim amp, the JL-2 has very little difficulty to drive anything thrown its way. If any Naim amp can control a speaker out there, that same speaker will be breeze for the CAT. I would even put my Counterpoint NPS400 amp against any Naim amp to compare with driveability against any speaker load out there.

Gregm - My older SoundLab A1s are not even close to 88db....probably closer to 84 or 85, and the CAT can drive this speaker with far greater ease than the Counterpoint amp that is rated twice the output. It's not an issue of rated power or speaker efficiency but rather how linear and stable the amp remains when the music material becomes more complex at higher and higher volume levels.

I had the ARC CL150 monos, also with 8 6550 tubes in triode, and rated at 150w. This amp was not at all capable of driving Magnepan 3.5 speakers to their potential. But to throw the CAT at these speakers was not a problem. So I would not put much focus on silly power ratings or dismiss an amp because its output is tube driven.

Sounds like the new VAC Phi 300 also should be able to drive your speakers with no problem. As long as you're talking about "last amp" purchases, you might want to read this review of the 300 by a fellow A'goner before your purchase:

http://forum.audiogon.com/cgi-bin/frr.pl?ramps&1148154313&read&3&zzlVac_man&&

OK, I have read a little bit about the CAT now, and this indeed seems to be a special kind of beast. Let us know how it turns out sound-wise. Another tidbit of my experience, however: The Obelisk is very sensitive to a good speaker cable. What do you use so far?

I have Auditorium 23 speaker cables. Recommended by Joe Fratus of Art Audio (a great guy), review on 6moons. I think they sound really good but I'm still a neophyte at all this stuff. Hodgepodge cable repertoire includes Jena Symphony IC, Poiema!!! IC, Stealth PGS Gold IC. I admit that a gut feeling is a bad rationale for dropping the kind of money a CAT requires but my sense is that it would work great. But that's why I'm soliciting opinions.