CAT Preamps vs Amps


I'm a proud owner of a CAT JL2 amplifier. Most of the threads on Audigon say great things about CAT's amps JL 1-3. People laud over the musicality, transparency and dynamics of these amps. However, when it comes to the preamps (Signature and Ultimate versions), it seems like the reviews are a mixed bag. In many cases, some CAT amp owners use other preamps.

Therefore, are the current CAT preamps (Ultimate) as good as their amps in terms of musicality, transparency and
dynamics? Are they on par? If not where do they fall short compared to the amps? What are better matches?
aoliviero
I, like Gbmcleod, am agog by what people have written about CAT preamps. I find them to be certainly among the best in dynamics, smoothness, liquidity and high frequency detail. They have stunning bass, in both depth and power. In my opinion, the bass is like nothing that I have heard from other preamps and once you have heard it, it is hard to give up.

Where I think that they fall down is in the area of low level noise, which obscures transparency and imaging to a slight degree.

This is why I spend more time listening to my First Sound Mk II 4.0 rather than my CAT Ultimate Mk I, but both are very fine products which, in my opinion, exceed the efforts of the other top brands which I have heard. Admittedly, my evaluations are prejudiced in that many of the brands which I have heard were not tube-rolled and, in my opinion, this can make all the difference between a presentation that is just so-so and one that is outstanding, but only if the preamp "has the goods".

What I have found is that it is difficult, if not impossible, to compare preamps with stock tubes. Despite what the manufacturers say, stock units do not come close to revealing what these units can do when tube-rolled.

If you are evaluating a CAT Mk III or later with stock Sovtek 6922's in V6 and V7 on line, or in phono add V1 and V2 to V6 and V7, you are really doing yourself a disservice. These MUST be replaced. I have tried a number of NOS tubes, but obviously not all, and I do prefer the Telefunken 6922 in the CAT Ultimate Mk I, like Bombaywalla said above. The EI 12AX7's are surprisingly decent sounding tubes in the CAT, but if replaced at V8 and V9 on line and if you use phono, replace the ones at V3 and V4 also, you can eliminate some muddiness in the bass that you didn't know was there until it is gone. Telefunken 12AX7's work well for this purpose.

Nothing that I have heard goes down deeper, giving both bass depth and power, a better lower midrange transition, with smoothness, solidity, liquidity and with dynamics to spare. Highs are sweet and detailed and extended. High frequency decay on the CAT when a cymbal is struck hard is exceptional and with these tubes, there is no brightness or forwardness anywhere.

Yes, the First Sound will stun you with its much lower noise floor. Yes, it will stun you with its "you are there" transparency. The small and well-defined images in the soundstage cannot be achieved on the CAT and the female vocals on the First Sound are truly exceptional in their up-front intimate presentation, but all this again, is only achievable after tube rolling.

Nothing is better than hearing the CAT properly fed go full out on music written for pipe organ. If the rest of your system is full-range, or nearly so, you will rattle the windows like few other preamps are able to do and yet you will hear all the subtlety and delicacy of the small trupets and whistles that pipe organs can also play, presented without any non-musical artifact When all the pipes get going in unison, you might feel that you are in church or that you are taking a tour of the great churches of Europe.

So my answer is an unequivocal no as to whether the CAT is just "very good" or lacks dynamics -micro or macro. Yes, it has been surpassed in some respects, but in overall presentation, it is worthy of very high praise indeed.
It's interesting to see this thread have activity again. As reported elsewhere here on A'gon, earlier this year I had a CAT UII on loan for a couple months to compare to the Io/Callisto.

The consensus here is that the Sovteks in the CAT must go and my experience indicated the same. There is too much fatigue and sharp edges with these tubes. And as others have reported, the Tele 12ax7 did not work at all in the CAT line stage nor phono stage. It does not work well in the Callisto either but it is magic in the Io.

For the CAT vs. Aesthetix comparisons, the two line stages use the exact same tube compliment. I had enough of the Mullard 6922/12ax7 sets to keep both line stages warmed up for hours. No doubt about it, the CAT line stage has greater dynamics, more clarity and openness in the very top and indeed has a greater presence and weight in the bottom. All of these were instant and quite impressive. But it only takes one return back to the Callisto to hear the multitude of underlying subleties to know something is very right here. There is structure, body, dimensionality with the Callisto that is lacking with the CAT. And this for me was all it took to hold onto the Aesthetix.

There is that instant boogie factor with the CAT. The dynamic contrasts and frequency extreme coverage just gets your blood flowing. And it is never excessive. This with the JL-3 amps is exciting. But once the piano starts or vocals begin, the CAT UII line stage falls short.

The difference with the phono stages was much more dramatic. There has been so much praise about the CAT phono stage. With the Io (non signature here at the time, but getting completely overhauled now at GNSC to far beyond an Io Sig), the CAT phono stage had no chance. The CAT phono had one-note bass vs. far greater tonal coherency with the Io. It was as if the second octave in the CAT phono had a dip; the Io was portraying string bass notes with phenomenol clarity that were lacking with the CAT phono. This was more evident with the full CAT vs. the Io/Callisto compared to the CAT phono into the Callisto vs. Io/Callisto. I think the CAT line stage's deeper coverage into the bottom octave more clearly shows the lack of coherency in the CAT phono's bass coverage.

Whereas there were clearly some pros/cons of the CAT line stage vs. Callisto, the Io tore up the CAT phono stage in every way. This was the opposite that I would have expected. I can only imagine how the GNSC rebuilt Io will perform.

I have since gotten some Tele 6DJ8 tubes and these in the Io and Callisto are phenomenol. The Mullard 6922 were my ref tube here, but the Tele has now taken this spot. But I find a mix of these two types is the way to go with the Callisto. I would like to hear how they perform in the CAT. I suspect it would be a similar step up. But still, not at all enough to bring on the magic of the Aesthetix. As much as we like to refine the sound with tube rolling, it all starts with a specific design and the CAT as well as the Aesthetix have their fundamental sonic character no matter what tubes we use in them.

For a system that needs some help in the dynamics or resolution departments, the CAT preamp has no peers. But if you are looking for a more spatial presentation, great decays, textures through the vital mid 4-5 octaves, the CAT will most likely not work for you. Perhaps the Legend will address these areas and conquer the opponent. But for now, for me at least, the Io/Callisto reigns above the feline preamp in pure musical enjoyment. And this is with the JL-3s.

John
Too bad you live in Minneapolis, Jafox, because I would like to get together with you for a preamp shootout. I have noted your posts in this thread and elsewhere and they does not correspond to my experience. I auditioned the Callisto, probably almost 5 years ago, in a store alongside the Hovland HP-100. I thought my CAT clearly bested the Hovland and the Aesthetix competed with neither. Of course, it is difficult to make these comparisons as tubes, associated equipment, cables and room/setup all play a part and as we have belabored here, tubes can play a huge part. There is no doubt that I missed smoething in that audition for some reason, as too many people speak of the dimensionality of the Aesthetix, even though there was nothing special going on in that audition with regard to dimensionality and the Aesthetix.

On the other hand, I would agree with you from my experience that day with the Aesthetix that the CAT clearly had better dynamics, bass depth and weight, better clarity and openness in the high frequencies than the Callisto, at least at that time.

I've never heard the CAT Ultimate Mk II and that may account for some of the difference that we hear, but I doubt that it is the full reason. I have heard many CAT's all the way back to the original ca. 1985, and while some sound a little different, they do maintain a similarity that I don't think that Ken Stevens created an entirely diifferent product in transitioning from Ultimate MK I to MK II.

As far as tubes in the CAT are concerned, I did follow Bombaywalla's link to his other thread where he discussed results of his tube rolling in the CAT. It seems that he
did not confirm your position that the Telefunken 12AX7's do not work in the CAT. It seemed to me that he rated the "Tele/Tele" combination second best to the "Amperex 7308/EI 12AX7" combo and he rated the Tele 6922/Mullard 12AX7" combo third. It seemed that the Tele/Tele combo was a little too "sweet" for Bombaywalla, although he found it very seductive and had a hard time turning off the pre in order to go to bed. He also described the Tele/Mullard combo as very sweet and seductive, but a little brighter, with the bass on the weak side. I can confirm this that the Mullard is both a brighter tube and is not as extended or powerful in the bass with the CAT.

In looking through all the responses with regard to the CAT, the main thing that we all agree upon is that the Sovteks are God-awful. To hear a properly set up Aesthetix
would be a treat and I would take on the challenge of trying to demonstrate what the CAT is capable of. When I participated in these sessions before, it is often much more difficult to achieve consensus than I thought it should be, but if I thought, after such an in-home audition, the Aesthetix was either better than the CAT or had qualities that I valued highly, I would admit it in a minute.

Too bad New York City to Minnesota is too far to carry my system on my back.

Hello Rayhall - I too wish we were closer. It is very exciting and educational to visit other audiophiles' home and try our gear in these other systems. I learned much from two local guys on the issues of PLCs and PCs specifically. The things that seem to be passed around over and over are the preamp and cabling.

I had the CAT UII for 3 months and played with it off and on, before and after the multiple day/night comparative process ... and reported what I heard/learned back to the CAT dealer. And he in turn made further suggestions on things for me to try. I went far beyond simply trying one piece in the system, then switching to another, maybe back again and then coming to a conclusion. The one thing I regret not doing then was to go back to all Sovteks in the Callisto, including those dreadful EL34's in the PS. This would have given me a more accurate comparison test that everyone else out there has most likely heard the Callisto when comparing to its peers.

As a huge fan of the JL-3s, and feeling that the multitude of chassis with the Aesthetix pieces is a major pain in the neck, if there was ever someone who wanted the CAT UII to perform like a GREAT preamp, I was/am that person. And the synergy preachers out there would tell me this would be THE BEST match with the JL-3s. And yes, the CAT's dynamic contrasts, absolutely incredibly resolving top end and bass performance won me over. But when I heard the Callisto do the decays and the leading edge of instrument and human-voice tones to bring on the body of such tones, the CAT lags far behind. The initial great impressions of the UII become a moot issue as the Callisto brings on enjoyment to the listening like no other.

To get another viewpoint on this, I had one of the local guys, Jadem6, come over. If there was ever a super critical listener and system tweaker perfectionist out there, this guy earns the blue ribbon. He too was very impressed with the CAT's strengths. But he dismissed the CAT immediately because it was not even close to the Callisto's spatial abilities. The UII ends up sounding hi-fi-ish compared to the Callisto.

I agree that the CAT preamp differences over the years can not be all that significant. But I can not imagine how you did not hear the Callisto's strengths over the CAT U1. When I first heard the Callisto with the Sovteks, the capability of this product was still clearly evident. The other tubes do take it to a new level as they do with the CAT.

Unlike Bombaywalla, I had no access to Tele 6922/6DJ8 at the time. I only had Amperex 6922 and Mullard 6922. And for both line stages, the Mullard was far more to my liking. Now that I have tried the Tele 6DJ8 as reported, this is my new reference. But contrary to Bombaywalla's report on the Tele 12ax7, I stand by my statement that it did not work well in the CAT nor in the Callisto. In both units the top-end openness was greatly reduced and thus the harmonics and ambience of the mid-range frequencies. And this is an area that I am hyper-critical. I would have loved for the Tele 12ax7 to work here as I have many of these for the Io and a pair for the Callisto or CAT would have been very convenient to use here as well. Here again, a scenario where I would have benefited from the result, the desired outcome did not occur.

It was the UII's weakness in the decays and dimensionality that I was trying to get one way or the other. The Purist Dominus PC helped, like it does with anything else, but it did not rescue the UII here. And the Dominus IC between the DAC and line stage as well as between the tonearm and phono stage, again did not do it. Believe me, I tried! And perhaps the Mullard took away some of the tonal coherency vs. the other tubes in the UII. But it helped this unit significantly in the areas of its weakness ..... but again, not even close to the Callisto.

I can tolerate a reduction in performance at the frequency extremes or in dynamic contrasts and not having the ultimate in low-level resolution. But I need instruments and musicians to convey real space with the tones going on forever and ever. It started for me 23 years ago with the ARC SP-8 and later the SP-10, and I have wanted it ever since. And today, the Aesthetix models do this like no others and they do a very good performance in every other sonic character. The areas which they do not reach the top of their class are easily made up for by the JL-3s and SoundLab A1s.

An interesting comment by another local audiophile who visited me a few months ago - he said he had never heard decays in any system like this before. I never did hear back from him on what line stage he ended up with.

When the Legend is available for me to try, you can be certain that I will be in line to hear this. I have not given up on the CAT preamp yet.

If you ever have a reason to be in Mpls, throw me a note and stop by for a listen.

John
Hi Rayhall & Jafox,

Jafox: good to read your review of the CAT UII after having played w/ it for 3 months. I guessed, when I spoke to you earlier this year, from your choice of words, that your review was not going to be favourable towards the CAT UII.

Rayhall cites my experiences w/ the tube rolling correctly from the other thread.
The Tele 12AX7 definitely is a winner in the CAT. It should come as no surprise - the Ei12AX7 is supposed to be a copy of the Tele smooth-plate 12AX7. I believe that the Ei factory even has some original Tele tube making equipment. Of course, it does not mean that it has to work. However, it comes to me as a major surprise that the Tele 12AX7 does not work in the CAT UII.
I'm using this combination at present - Tele 6922 & Tele 12AX7 & am enjoying it immensely.
It looks like we are hearing things/music in totally different ways!
Also, Mullard tubes are wrong, wrong, wrong, wrong, wrong, wrong tubes for the CAT!
Of course, one is allowed to tube roll any & every tube that one has on hand - nobody is there to stop the user from doing this. However, I've found it worthwhile to solicit an opinion from the designer/manuf before doing so. If nothing, I take his words under advisement. More often than not I follow his guidance 'cuz I feel he knows more about his design that I do.
One minor communication w/ Ken Stevens will tell you how wrong Mullard is for any CAT!
It is indeed unfortunate that you had Mullards for the 3 month audition period! I feel that you severely hobbled the CAT UII by using those tubes. The CAT *should* have performed terribly w/ Mullard tubes & it did, as you stated!
2ndly, talk to the designer/manuf of the CAT before you try the Tele 6DJ8. From my conversations w/ Ken Stevens, DO NOT use 6DJ8 in the CAT. They'll work but the bias is not set correctly for that tube. If memory serves me correctly, the 6DJ8 tube takes more bias current than a 6922. The bias in the CAT is set for a 6922 & it'll not let the 6DJ8 perform to its max/best. It'll hobble the CAT UII (once again).
I think that the correct tube complement(s) need to be used in the CAT UII before a conclusion can be made vs. the Aesthetix.
I cannot believe that Ken Stevens, who is absolutely behind the 8-ball on dynamics, timbral accuracy of instruments & voices, attack of instruments, soundstage width & depth, would make a preamp that lacked these qualities.
If he did (consider this for grins), then, how did the CAT power amps, all of a sudden, get these qualities???
A man/designer who has no knowledge of dynamics, timbral accuracy of instruments & voices, attack of instruments, soundstage width & depth for his preamp can, suddenly, discover these qualities for his power amp??
You do not see the inconsistency of this??