CAT Preamps vs Amps

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??

Thank you Bombaywalla for your response. Let me addres your issues one by one. And yes, I knew my comments would get people's blood boiling.

First of all, as stated before, I have not heard the Tele 6922/6DJ8 tube in the CAT. I have no doubt it would work very well here; every place I have tried the Tele 6DJ8, including the Counterpoint NPS400 amp, there was a marked improvement in tonal coherency. I am 110% sure of one thing: Tele 6922 tubes in the CAT UII are NOT going to rescue this line stage from its weakness in portraying space and decays. This tube was a very nice refinement in the Callisto and Io, but it did not take either of these units to a new level in this sonic area. So if anyone thinks they are going to get the Aesthetix strengths by putting Tele 6922 tubes in the CAT, they are in for quite a disappointment. No tube change is going to do this. The differences here are inherent in the respective designs here.

As I have heard the Callisto vs. the Calypso many many times now, they are so very much the same except in one key area - the issue of dimensionality. And the two designs are quite similar except one key factor - the Callisto has a tube PS. Hint, hint. This could very well be the reason why the UII lags behind the Callisto like the Calypso does in this manner.

Obviously, our experiences on how the Tele 12ax7s worked in the CAT are polar opposites. I like this tube very much, but so far only in the Io. What it does in the CAT UII, Callisto and Manley Ref DAC is consistent - the soundtage and dimensionality are greatly diminished in my system. Perhaps there is "synergy" between the Tele 6922 and 12ax7 in the CAT, but this too sounds more like a leap of faith rather than a reality.

I am not going to get into a pissing match over what tubes are right or wrong in any product. To lecture me that Mullard tubes can not work is nonsense. They might not be the ultimate tube here, but for $100, just one pair in the line stage took the UII into far greater sonic performance. This is the tube I had at the time, and with it, I observed a significant improvement over the Sovtek. If nothing else, it is a wonderful starting point if it is the only available tube at the moment.

That Ken Stevens shared with you that the Mullards were not a got tube here is fine - I accept his opinion here. Let me be frank - he does not want any of us to even change the stock Sovteks. And yet it is a consensus here - until we get rid of them, one has not begun to hear the potential of this product.

As for me hobbling the UII experiment with only Mullards indicates to me that you're getting a little ahead of yourself with coming to judgement here.

"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."

You are not paying attention to what I have written in this thread at all!!!!! In the context of dynamic contrasts and initial attack of notes, I have repeatedly stated the UII line stage outperforms the Callisto by a significant margin. And this is very evident with the JL-3s. From my amp listeneing sessions, no amp can touch the JL-3s in this regard. And we are driving some very resolving speakers here: SoundLab A1s. So nobody needs to lecture me about dynamics or transient speed. It is why I bought the JL-3s and it is what I immediately noticed was the UII strength.

I have been very kind to simply state that the Io was far beyond the UII's phono stage. And this was why I did not put anywhere near the effort between these two as I did with the line stages. As stated before, I threw everything at the UII but Tele 6922s and the kitchen sink to bring on the magic and it just did not happen. I suspect very few people would have done so much with this unit as I did.

"The CAT *should* have performed terribly w/ Mullard tubes & it did, as you stated!"

And again - you were not paying attention. I never said it performed terribly. I stated the UII's strengths over the Aesthetix. And I then followed through where the Aesthetix excels over the CAT, i.e., harmonic textures, layering, decays, ambience, etc., etc. Rather than you scold me for my incompetence and/or lack of responsibility for sharing my experiences here with the Mullard tubes, I suggest you get on down to your Aesthetix Io/Callisto dealer, and take a box of Mullard, Tele and Brimar tubes, and hear for yourself the areas where the UII falls behind. Oh, and so there will be no bias on lack of dynamic contrats from the audition, maybe you can also borrow a pair of JL-3s.

As for the issues of soundstage, decays, body of the instruments, etc., even the CAT amps lose out to some of the competition here.....the Atmasphere amps driving the SoundLabs bring on a most incredible performance in these key areas over the CAT. And this was observed with a direct comparison between the amps. When I heard this at the dealer, I remember telling him I wanted both amps in one. And the same holds true with the UII and Aesthetix. But this is not possible so the best I can do is pick one from each side of the fence. And to me, the Aesthetix/JL-3 pairing is incredible. Everyone who has heard this with the A1s, has said the same.

Perhaps the UII and the Atmasphere amps would be the flip side of this success. But a CAT/CAT setup is just too much into the neutral zone for me. Other people love it and I respect that. I just need a little more direction into the dimensional zone.

"You do not see the inconsistency of this??"
Not at all, and maybe you won't either once you pay more attention to what I have written all along. There is no perfect product in the CAT nor Atmasphere nor Aesthetix nor whatever camp. The key is to assemble a system in such a way that brings on the strengths of certain pieces that stand out and try to improve on that component's weaknesses through other changes in the system. And this is what I have done.

The post by Bart(Poswbp555) where he spoke with Ken Stevens is interesting. This ought to be very exciting when the Legend comes along. But the full function preamp by Michael Elliot is also much on my mind. We all benefit when these very talented engineers continue to improve on their past great achievements.

I think I have shared all that I can here to convey the pros/cons of the products under evaluation. For me to continue here will only result in rehashing the same information through and through. And as exhibited by Bombaywalla, my instincts were correct - people get upset when their reference product is put under a microscope.

John

John,

Thanks for your update. Appreciate your time to write a detailed rebuttal post.

>> And yes, I knew my comments would get people's blood boiling.
NO! my blood is not boiling. Far from that, let me assure you & double assure you, if I may.
When I wrote my post earlier today, my intention was to invoke a debate & not a screaming match.
At no point did I "lecture" you about Mullard tubes - it was 1-line statement.
At no point did I "scold" you for your "incompetence" or "for your lack of responsibility for sharing my experiences here with the Mullard tubes".
You have become way defensive & aggressive than, I think, my post called for, if I may say so.

>> And as exhibited by Bombaywalla, my instincts were
>> correct - people get upset when their reference product
>> is put under a microscope.
Let me say again, I'm NOT upset that you put the CAT UII under the microscope. On the contrary, thank you for doing so! My ego is not hurt, my sentiments are not hurt. OK?
I'm not here to convert you to a CAT preamp person & my post was not intended to do so either.

I will say this: you & I are hearing music *very* differently. There is a wide gap.
Maybe I'll conclude the same as you when/if I get to hear an Aesthetix product? Who knows.....

I have to agree with John (Jafox) on the sonic qualities of the CAT U2. I am hearing similar strengths and weaknesses to those he describes. I value a liquid, musical, melt in your ear three dimensionality over dynamic slam (it would be nice to have both obviously). I may try the Atmasphere in combo with the CAT U2 in the future to split the difference between their strengths. Bombaywalla,
I haven't read your thread on all the tube rolling combos you have tried in the CAT yet but I'll bet you that the Amperex 12AX7 D getter long plate (circa 1950's at 200 to 300 a pair)will significantly outperform the EI 12ax7. John is also correct about Ken Stevens adamantly rejecting swapping the stock tubes in the CAT U2, so why are you referring to his rejection of the Mullard as a suitable replacement for the stock tubes when we all agree the stock Sovteks are dreadful. Anyway, thanks for doing the tube rolling, these are the kind of experiments that can save us money in a very costly hobby. Bart