CAT Preamps vs Amps

no opposing view from my side. I've got an earlier version of the CAT SL1 - the Signature Mk3. This is also a simply excellent preamp, if I may say so.

if you look @ the development @ CAT, you'll notice that the preamp came 1st way back in 1986. There was no power amp @ that time. So, the SL1 has been refined over nearly 20 years to this day! I'm inclined to believe that the CAT preamp is just as musical, transparent, dynamic, etc, etc as their power amps. the CAT gear serves up music without any sugar coating & is one of the few pieces of gear that tries very hard to be true to the recorded playback medium. often I've read people chosing to stick w/ the CAT power amp & give up the preamp, if they have both, on the notion or observation or both that a CAT pre & power might be too much of a good thing in that both pieces are exacting in their sound hence together they would render the music in a too dry manner. Well, it's a personal choice - one man's 'too dry' music might be another's 'just right' music. Admittedly some/many people like their music coloured. So be it! So, it doesn't matter what these other people think of CAT preamps & what they chose to use in lieu. However, it's important to exactly note (when such info is offered/posted) why they opted to use another preamp & see if those criteria exist in your system as well &/or you have a very similar music-delivery taste. If so, you might be better off talking one-one w/ that member &/or trying that other preamp in your system. In the end, of course, select what's right for your system & your ear. It's a system built to suit your needs & not the critics'. FWIW. IMHO. YMMV.

I read John's (Jafox) long post. (poor John he was "compelled to post!! LOL!)
I think that John underscores my point - know why people are using other preamps, evaluate whether similar or exact need exists in your particular system & audition/purchase preamp accordingly.

To that effect, I think some of the AN-Kondo & AN-UK preamps like the M6 might go well w/ a CAT power amp. AN components are mostly about music & PRaT rather than being exacting & they *could* provide a suitable balance to the overall sound. The M6 is e-x-p-e-n-s-i-v-e but then it seems that you are swimming w/ the real big boys so it should be in your budget. FWIW. IMHO.

John,
You are most kind to offer me a chance to listen to these prized tubes!
Yes, I would love to have a chance to hear them in my system. Ever since I got the Tele 6922, I've been conjecturing just how the sound would be if I could swap in a pair of Tele 12AX7s.
Yes, Ken Stevens uses the Ei 12AX7 for a good reason, I suppose!
I'll send you an email off-line re. your generous offer. Thanks much!

I had an update re. CAT preamps & I thought that I'd post it here FWIW. There are other threads that also talk 'bout this subject here on Audiogon but they might be far back in the archives.

I took member "rayhall"(A'gon) & "TubeNewbie"(AA) advice & got a pair of Telefunken 6922 tubes. I also bought a pair of Amperex 7308 USN-CEP, white label tubes. Both these tubes were bought for the V6-V7 only position. They 12AX7 tubes I use are Electro-Harmonix. All other 6922 are Sovtek provided by the factory.
By merely tube rolling the V6-V7 tubes w/ the above 2 mentioned brands has made the sound my CAT SL1 Sig Mk3 even better! I love it more!
The Telefunken tubes impart more of what the Sovtek 6922 gave - better & fuller bass & a touch sweeter highs are the 2 items I note the most.
The Amperex tubes give a touch of warmth to the midrange. it's more seductive now but not so much that it's syrupy. Bass remains full & robust. The highs remain extended & retain their sparkle.
Both these tubes allow me to seemingly have my cake & eat it too in that I don't seem to compromise the CAT intended sound while I can fine tune it depending on my mood/preferred music delivery.
I believe that 'rayhall' uses Tele 12AX7 in V8, V9 & a Tele 6DJ8 in V10. Wish I could too but my pockets aren't that deep! :-)
Just FYI. FWIW.

Hi All,
I posted my findings plugging in the 12AX7 tubes that Jafox kindly sent me. I posted this in a more relevant forum. Here's the link http://forum.audiogon.com/cgi-bin/fr.pl?aamps&986396504&openfrom&1&4
if anyone is interested.
FYI. FWIW. YMMV.

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??

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.....

Bart,

>> 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.
maybe so. The $ amount is a bit too extravagant for me - I cannot convince myself to spend this much on NOS tubes!
I also tried the Telefunken 12AX7. I think that I had a smooth plate pair (if memory serves me correctly). Like Rayhall wrote, I found the Tele 6922/Tele 12AX7 combination the best. The Amperex 7308 USN-CEP/Ei12AX7 combination the 2nd best.

>> John is also correct about Ken Stevens adamantly
>> rejecting swapping the stock tubes in the CAT U2,
Having spoken to Ken Stevens several times at length, he informs me that he has "optimized" the CAT preamp design for the Sovtek 6922. That's why he's so insistent on retaining those tubes. I didn't ask him specifically what he meant by "optimized" but I surmise that he means creating the bias specifically for that tube to run it in its most linear region + the power supply filtering for its heater supply.

>> so why are you referring to his rejection of the
>> Mullard as a suitable replacement for the stock
>> tubes
Again, speaking at length w/ Ken Stevens informed that the Mullard tube was ill-suited to the design on the CAT. As you know, certain tube types work well with certain tube preamps i.e. if a certain preamp uses a 12AX7 then not all brands of 12AX7 will suit this preamp. The CAT is no different - the Mullard tubes make the CAT perform at its lowest. I found the same when I tried a Mullard pair generously lent to me by Jafox.
However, I did write the following in my original post:-
"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."

I'll have to listen to an Aesthetix Callisto & determine for myself how its sound compares & contrasts to the CAT preamp. I'm not convinced that the CAT can be faulted for the lack of portraying space, decays & harmonic textures.

Bart,

>> So for you to say that Ken's design was optimized for
>> the Sovtek is absurd.
I'm merely conveying to you what he told me. For a clarification you should call Ken & ask him yourself what he exactly means.