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CAT SL-1 vs. FS Presence Deluxe & SET/hi-eff spk

I've been considering a used reference level preamp for a few years now and just got into the position to afford one. Right now, I am using a S&B TX-102mkIII TVC into 6-8wpc SET amps driving 97dB/8ohm speakers. This setup is dynamic, transparent, and extremely quiet. The only downside is most source components are not designed with robust enough output sections to drive amps directly(my DAC can easily, phono pre - no). I'd like to stick with tubes, but components have to be quiet or hiss/noise is readily apparent.

The new June 2007 Soundstage review of the CAT SL-1 Ultimate states:
Like the VTL TL-7.5 I reviewed a while back, the SL1 Ultimate has rather high voltage gain -- 26dB. Voltage gain is an indication of how much an amp or preamp is amplifying its own noise, and when tubes are employed, there is generally some audible noise. Voltage gain is expressed as a number that represents a multiplied value (20, as in 20 times) or in decibels. A certain voltage-gain figure isn't inherently good or bad, but high voltage gain from both a preamp and amplifier can create background hiss, especially if your speakers are sensitive.

Of the amps I had on hand, only the Lamm ML2.1 and CAT JL2 Signature Mk 2 were suitable for use with the SL1 Ultimate Mk 2. The Lamm M1.2 Reference, with its 32dB of voltage gain, produced noticeable hiss with the CAT preamp. When he visited to install his products, Ken Stevens remarked that the hiss produced with the SL1 Ultimate Mk 2 and Conrad-Johnson Premier 350, which has almost 35dB of voltage gain, was "not too bad." It would have been completely unacceptable to me. As a guesstimate, if your amp has 25dB of voltage gain or less and your speakers are 90dB sensitive or lower, you should be OK with the SL1 Ultimate Mk 2. As gain and sensitivity rise, however, the outcome will be based on your tolerance for background hiss.

Kind of a "red flag" for me, my Art Audio PX-25 has a high input sensitivity of 700mV(350mV as an option). That, with 97dB speakers could cause problems. But, reviews and real world use often differ substantially. Unfortunately, it is highly unlikely that I will be able to try both in my system.

I've read all the archived threads comparing/contrasting the two preamps, but almost all the respondents systems that I looked up were amazing, but moderate to low-efficiency speakers with higher powered amps. Not really applicable to my situation.

So, has anyone used the CAT SL-1 or FS Presence Deluxe in a high efficiency system?
darkmoebius

Showing 1 response by rayhall

rayhall
393 posts
 
Not in a high efficiency system, but I have both preamps (CAT Ultimate Mk I and FS Presence Deluxe Mk II 4.0) and if you've read all the posts on the comparison of these two, you have probably been reading a lot of my responses on threads. With my Vandersteen 3A Signature Speakers (86db-87db sensitivity) and Pass Aleph 4 amp (20dB gain), there is hiss with the CAT which can be heard at the listening position when music is NOT playing. Both are excellent preamps, the CAT exceling in the bass and up through the lower mids and the midrange. It has the best deep bass that I have heard in a preamp and a bass weight that others which I have tested don't. Excellent dynamics. It is smooth and a little bloomy. No upper frequency bite or harshness. Highs are extended and detailed. F.S. is more detailed -- not as smooth as CAT. The bass is not as deep -- at least as not in my system. What the F.S. has over the CAT is imaging and transparency, which is probably due to the difference in noise. FS is absolutely silent and gives the sense of a totally black background. CAT will sound slightly veiled in comparison to the FS. Soundstage painted by the F.S. is very wide and instruments and voices -- particularly voices -- can be more precisely located within the stage. CAT also has a wide stage -- perhaps deeper than F.S. -- but imaging is more diffuse. F.S., particularly with the right tubes, has excellent dynamics, maybe better than CAT, but not the bass. You'll need to tube roll both in order to get the best from each.
In my system which admittedly is not high gain, high efficiency, there is hiss with the CAT. It is not so loud as to be annoying and you cannot hear it at the listening position if music is playing, but in comparison to the F.S., I believe that the self-noise does contribute to one of its flaws, which is (by comparison,only) reduced transparency. Which do I listen to more frequently? The F.S.
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