Review: Aesthetix Callisto Signature Tube preamp

Category: Preamps

Aesthetix Callisto Signature line stage,
This is something less than an actual review, but I felt strongly it needed to be said. Jafox was kind enough to bring his Callisto Signature with the one power supply option over to compare it to my Aesthetix Calypso line stage. (Please see my full review of the Calypso to put this review in context)
The Callisto and its separate complementary phono stage the Io, come in a number of configurations. This review is only relating to the Callisto Signature. The following are excerpts copied direct from the Aesthetix web site:
The Callisto Line Stage and Io Phono Stage can be used together as a complete pre-amplifier system or separately in line-level only systems, add-on phono, or Io with volume controls as a dedicated phono preamplifier. The Aesthetix Power Supply is the size of a power amplifier. Identical for all Aesthetix audio chassis, each Callisto or Io requires a dedicated Power Supply. Separate umbilical cables feed each channel of the dual mono audio chassis… Each separate amplification or buffer stage has its own power supply filtering network and regulated heater supply to isolate individual sections and prevent interaction.
The Callisto Line Stage optimizes both single-ended (RCA) and balanced (XLR) inputs and outputs. The Callisto audio chassis contains one main amplification section and an output buffer section. The first section is a medium gain, low noise, zero feedback (or 6 dB feedback from single ended sources) differential amplifier composed of a 6922 tube and a 12AX7 tube. Lastly, the signal is buffered and sent to the output jacks in balanced form.
The Mark II feature custom Roederstein resistors, replacing the standard metal film resistors in the earlier version. Custom made coupling caps feature twice the output capacitance to provide deeper bass and the ability to successfully drive lower impedances.

The Signature versions use custom-made inter-stage Teflon coupling capacitors, replacing the polypropylene units, with a cost factor of over 15 times greater per unit…. All of the input and output wiring is replaced with specialized Cardas Teflon coated signal wire… The Signature units obviously take advantage of all of the Mark II advancements. Both original versions and Mark II units can be upgraded to Signature status.

Each Aesthetix unit is hand built. All units undergo a rigorous test procedure, which includes auditioning in a high quality audio system.

Aesthetix Io Mark II $6,500
Aesthetix Io Mark II with Volume Controls and 2nd input $9,000
Aesthetix Callisto Mark II $9,000
Second Power Supply Mark II $3000

Aesthetix Io Signature $9,000
Aesthetix Io Signature with Volume Controls and 2nd input $11,500
Aesthetix Callisto Signature $11,000
Aesthetix Signature upgrade $3,000

Jafox is a tube and analog guy so I had some concerns as to how he would receive my Sony SCD-1 digital front end, Aesthetix Calypso line stage (the single box little brother to the Callisto), two Plinius SA-102 solid sate amps and Dunlavy IVa speakers. We started the audition with the Calypso in the system. I played a number of midrange heavy, acoustical pieces from Sara K. to help him get used to my system. We then moved on to a few Patricia Barber pieces followed by Lucinda Williams. We then went to two pieces we had heard on his analog system a few days earlier, Norah Jones and Pink Floyd. Over the hour or so Jafox was able to begin critiquing my system with excellent observations. He felt the piano reproduction was tonally better than any digital system he had heard, but he was bothered by the lack of acoustic decay. He was missing the body, and wholeness of his tube system. We both agreed our two systems were remarkably similar tonally, but his was fuller, warmer and more liquid. Mine was drier, more analytical. Imaging and definition as expected was better in my system. Pace, rhythm and tempo were remarkably similar.
I believe Jafox had a good understanding of my system at the end of our one hour session. He was very much missing the body and added weight of his system. He expressed he missed the warmth and fluidity of his analog/ tube system. This was pretty much what I expected, but I was impressed by how astute Jafox was, and how well he was able to describe what he heard and what he felt my system lacked.
Then it was time to switch line stages. First observation with no signal but volume turned up about 1/3. (approximately listening level) The system was DEAD QUITE! I needed to put my ear within 5” of the speaker to hear any noise. This is roughly the same as my system has always been. We first played Pink Floyd, the very first note and I heard “Oh WOW” from Jafox. A smile came to his face as he settled back into the listening chair. Body, depth, weight, fullness and on I go with adjectives that can explain how much this line stage added to the recording. All the detail remained as strong as it always has been; it simply was fuller and more dimensional. We then played Patricia Barber. Piano was as right tonally as ever, but now the strings held there notes longer. The decay was complete and full, exceptionally believable. Patricia’s vocals were warmer and fuller. I commented to Jafox that her voice was richer than live. Yes, I believe the Callisto has added a richness that is not quite natural, but if this is how unnatural sounds, I’ll take it. Then I noticed during an acoustic guitar passage that I heard the players hand kind of stick and squeak on the neck of the guitar as he changed cords. I’ve listened to this disk a hundred times; I never heard this as something human and real. It’s always been just a sound suspended in space. Detail is enhanced with a richness and humanness that was lacking before. Every part of the sound stage was now anchored to a physical object. I didn’t realize this had been a problem in my system, but in retrospect some sounds were simply hanging in air without context. The Callisto has created this context.
Everything was fuller, more life like with a pureness that I loved and best of all I lost nothing. The background is still pitch black, the detail is just as involved and the pace was perfect. Tonality is beyond reproach, decay is exact and extremely entertaining. Jafox, who has created an amazing synergy of analog and tube gear was heard saying “I could live with this” as he again settled back with a look of contentment. Yes the purest solid state/ digital guys would complain that this was not as clear and etched as they demand. True enough, but it will only be a select few that would have this reaction. If you love your Wadia digital feeding Krell amplification while driving electrostatic speakers, this will not be your heaven. But if you’re anyone else this is simply amazing!
So here were two audio geeks from complete opposite sides of the hobby coming together one night to find complete agreement, the Aesthetix Callisto is perfection. In order to tie this review back to the Calypso it should be pointed out that Aesthetix has done an excellent job pulling the qualities of the Callisto into the much more affordable Calypso. Most of us will never dedicate this much money into a line stage, but if you want perfection it’s in the Callisto. If you want a very special line stage that is quite musical it’s in the Calypso as well as the Callisto. Is the Callisto worth almost three time the cost of the Calypso, it depend on your wallet and your goals in a system. If you’re looking to go as far as you can go, the Callisto probably is three times better. It was that amazing in my system, far greater than I thought was possible.
What will I do? It’s mighty tough to justify an $11,000 line stage when I haven’t been healthy enough to work for two years, but in another time, another world I would upgrade in a second. Given that I probably will never be fortunate enough to own this line stage, I just hope I can be happy with my system after hearing the Callisto. Today however, my system sounds like crap and I can only hope the memory of the Callisto fades fast…

Anyone want to by a Calypso for $11,000? Think of as charity.


P.S. Thanks Jafox

Associated gear
Sony SCD-1 digital front end
Aesthetix Calypso
Two Pinius SA-102 amps, bi-amped vert.
Dunlavey IVa speakers
Nordost Valhalla cables

Similar products
Hello Jadem6 and Jafox,

Based on your experience, is the Aesthetix Callisto Signature as good a linestage when used single-ended exclusively compared to balanced mode? I was nearly tempted to spring for a pre-owned Callisto Signature but was concerned because I have a single-ended digital source, a balanced analog source and a single-ended power amplification. I am not sure if the Callisto would blend well with my system. Right now, I have a balanced to single ended BAT adaptor from my BAT phono pre to my linestage.

Do either one of you have any comments on the sonic merits of the Callisto in single-ended mode?

Congratulations on a great review!!!
Peepoy2, It will be great. My system is all RCA connections while Jafox is all balanced. You should have not trouble what so ever.
J. D. Thanks for your thoughts and a nice review. Keep looking until you get that Callisto (they do come up for sale used). They are special units (pure tube design and great parts quality). I have an Io Sig and it is extraordinary. I have a c-j ART 2 but have always thought of going with the Callisto - it is not that the ART 2 is lacking, I just thought the synergy between the Io and Callisto would be worth a try!


Now go out and buy the Tom Evans Vibe a Pulse power supply preamp and really hear what that preamp can do, and it is a SS design. There was one here for $4K recently, a real bargin.

Happy Listening.
JD is quite a detailed writer. I had to smile and laugh and smile more as I could see he was very alert to my reactions (the good and not so good) of his system. Not only does he take the blue ribbon for noticing detail in his and my system far more than I do, but now I see that he deserves this award for noticing the detail of one's observations while listening.

I have yet to meet anyone remotely close as this man to deserving the title of "Tweak Geek"! And this has much to do with why his system does piano like no other digital based system I have heard.

As JD pointed out, the two Aesthetix products have great sonic similarity. Only in the context of the areas that he so well described does the Callisto pull away and significantly at that. The big difference here has to be the tube regulated power supply of the Callisto.

I have heard and owned many preamps and line stages, and I still have yet to hear any SS product in this link of the system exhibit the dimensionality and/or decay that brings on the naturalness of the human voice or piano. On some recordings there will likely be a little too much of a good thing in midrange presence. But of all such preamps I have liked that exhibit this quality, I feel the Callisto does this in a most superb manner. Perhaps this is due to its incredible bass authority (shared by the Calypso) and its highly resolving trebles (also shared by the Calypso) to still bring on an incredible coherency. But as JD writes, "I'll take it". And that's a comment from a perfectionist audiophile. Hey Albert, I think we have another convert!

There is much time and effort that we all need to take to balance out the warmth and dimensional side of the system with the highly detailed and neutral side of the system. For JD and myself, with two very different systems, the Callisto is one of those products that covers both sides of the fence so well. He and I would both agree we have heard nothing like it in our systems.

Concerning the issues of balanced and single-ended, actually, I use a mixture of both. My tonearm cable is XLR so I use this into the Io and then the Io drives the Callisto with balanced cables. I also use balanced cables from the Manley Ref DAC.

The CAT JL-3's only have SE inputs which required me to find another cable to replace my long time favorite NBS Statement XLR cable. Here I managed to find a 25' SE MIT 350 EVO cable that works very well. In my system, the Callisto has no problem at all to drive these long SE cables to the amps. I did try the NBS into the CAT using adaptors, and thus only one phase of the Callisto output was being used. Between the Callisto and CATs, I prefered the MIT just slightly here because it has a little more neutral midrange tonality vs. the NBS. Again, it's a balancing (no pun intended) act.

This coming week I have a bunch of tubes arriving from all of Albert's great recommendations. When I get these installed in the Callisto, I'll have JD come over again and perhaps he can rewrite this review all over again. And then if I splurge with a 2nd power supply, we'll have him do it again. 8-)

Thanks Jafox, i cann't wait to come over and "play" some more. I promise I will keep "most" of my tweaking toys at home. :- )

according to Jim White, the Callisto takes a few hours minimum to really warm up before it sounds its best and based on my experience, i'd have to agree. hopefully you guys plugged in the Callisto while you were listening to the Calypso. if not, you may not have heard the Callisto at its best. :-)
John and JD, this review was magnificent. This makes me truly think I have to keep the Callisto in the running for my next linestage. Have you guys had the opportunity of comparing it to some First Sound models in the same price range? Or perhaps the Supratek Cabernet?
I know, I know, someone is probably already saying I should get my act together and make up my mind once and for all, and finally take the plunge, but. . .
Guidocorona: Yes absolutely, keep this model as a serious contender. But just be prepared for the Callisto and Io units to take up a lot more space than your average preamp.

There are some incredible preamps out there but there are several that I have heard that immediately destroy the musicality of my system that I have worked so hard to achieve. Over the years this continues to be the most sensitive link in my system.

As much as we'd like to hear the "great" models, it really is tough to get the opportunity to do so. It looks like JD and I have pretty much exhausted our options with our local dealers. The Atmasphere MP1 might still be a possibility for consideration as it is available through a local dealer. Otherwise it looks like only through other local audiophiles might we have a chance to do a comparison in two systems like we did here.

Another listen to the BAT 31SE vs. the Callisto yesterday and I am still very impressed with this BAT model. It portrays the 3-dimensionality and body of the instruments much more like the Callisto than does the Calypso. But the 31SE does not have quite the bass extension nor the openness in the top frequencies as the 2 Aesthetix products. The Callisto is unique in my experience in that it brings on dimensionality, frequency extremes AND dynamics like no other line stage I have heard in my system.

As I have mentioned here already, I am awaiting the Michael Elliot Aria preamp. Imagine how a modern version of the Counterpoint SA9/SA11 might sound today and you have a recipe for serious competition to the Aesthetix and a top-tier standing. And like the Callisto, the Aria WV preamp uses an all-tube regulated power supply. I believe this has a lot to do with the Calisto's magic.

Fmtien: I had my system just on short of two hours before JD came to my home. And the first thing we did was power up his Calypso while he got "acclimated" to my system with the Callisto. And hour or so later, we switched to the Calypso and played the same tracks again. And then back to the Callisto for another couple tracks or so and then a few minutes back to the Calypso where JD had had enough! 8-) So if anything, the Calypso was not given a fair warmup of only an hour or so at the beginning but at the end it had been on for over 2 hours and still the difference was as dramatic as the hour before.

When I took the Callisto to his home, the first thing we did was get it powered up. He played over an hour of music in his system. I suspect the Calypso had been on for awhile. A switch-over to the Callisto and the same character differences was right there as at my home. We both heard plenty after just an hour to confirm what I feel we both knew from the time at my home.

JD: Tonight I made another step forward with 4 Siemens 6922 and 2 Sylvania 6SN7 replacements in the audio chassis. Already I have a noticeable increase in dynamic punch than with the Sovteks. And this week I will get the Mullard EL34s for the PS which Albert writes is even more of a dramatic improvement over the stock Sovteks. So I might need you to come over soon to write an addendum to your review with these new tubes. 8-)

And heaven forbid the 2nd PS in my future. I can see how this and the Io could become an obsession with tube rolling. I must work hard not to let this get the best of me. I will leave such attention to detail to JD!

I have only a couple comments to add to Jafox’s post. First it should be pointed out once again how pleased I was with the Calypso. (And still am.) But in order to fully appreciate what a great pre-amp the Calypso is you must read my review, and understand I have tried a number of ~$5000 pre-amps during the years. The Aesthetix is in its own category when competing with its rivals.
Secondly it’s very important to point out that Jafox and I are night and day in our system directions, yet we both without ever meeting, created extremely similar tonal qualities in our systems. For the two of us to be this pleased with a piece of gear (Callisto) says volumes about how special it truly is. When Jafox comments about the BAT pre-amp I cringe. When he discusses the other great (complex at times) pre-amps I roll my eyes. I have not found the magic of the Aesthetix designs in other products within the context of my system. The Callisto is truly a great product and if you are considering a line stage in this price range than you must already have a great amount invested in your system. To not audition this product would be cheating yourself from knowing its’ potential.
I can only imagine the improvements we will hear with N.O.S. tubes. As I discussed in my review of the Calypso, tubes made a very significant difference in the quality of sound. Albert Porter has posted a couple times over the years the tube combination that best enhances the Callisto’s sonic qualities. Below is a reprint of that (Without A. Porter’s consent no less) I will ask Audiogon if they can amend my original review as I should have included this.


Regarding the comments by Bud and Rayhall, the 6922 Sovtek would be my first change. For additional midrange and air, try the Siemens 6922 CCa or the Amperex US Military 7308 CEP. If either of these produce too much midrange presence, try the Mullard 6922 (gold pin). Realize, that when you upgrade to one of these higher resolution NOS 6922's you are listening with more intensity to the weaknesses of the remaining (original) tubes. You are judging the replacement, plus all that it exposes downstream. If after changing to the CCa or CEP, you find that there is too much "grit" in the sound, try swapping the 6SN-7 as described in my long post. After that, if you are feeling adventuresome, trade out the first stage 12AX7 tubes (Io only). Note, these 12AX7's are the ones I warned about, get TESTED, ultra noise tubes for this position. My first choice and the most beautiful sound is the Telefunken 12AX7. Other options are the RCA 5751, a US Military version of the 12AX7. The 5751 will alter the tonal balance somewhat, as it is not an exact replacement. There will be a slight loss in gain, with improved signal to noise and lower distortion. Overall, the sound will be a bit more on the dry side. One final suggestion would be the 12AX7 French Mazda. A good sample of this will produce significant improvements in high frequency transparency, especially compared to the Sovtek. However, the Mazda has not been without problems in my experience. The samples I received are not equally reliable or equally low noise. Some will play perfectly for many months while retaining their original "voice" while other samples will develop horrible micro-phonics and tube noise in as little as a week. This is a situation that could lead to disappointment with the Io, when in fact, the tubes are the culprit. Unfortunately, there must be some risk and experimentation within your own system to determine what is best.

forgot to mention...nice review of Jafox's Callisto Signature! i've found it to be the best line stage i've had a chance to own. :-)

another thoughtful and (unusually) useful review. bravo!

fwiw, i, too, am a big fan of jim white's designs. my most recent audio system purchase is an io signature (the first shipped with platinum faceplates). this is partnered with a boulder 1012 pre/dac and a pair of the most recent nagra vpa's, all connected fully balanced with tara, 0.8. so far, my valve/ss/valve electronics are producing the best sound i've heard in my decade's-old listening room.

I did not mean to make JD cringe here. I do recall him telling me he was not at all impressed with the BAT 50SE. If it is anything like the 30SE, I understand why this is. But the 31SE has a very different sonic signature altogether. I heard the 30SE vs. the 31SE back to back at the dealer. The 30SE had virtually no life in the top frequencies which robbed the music of its harmonics and ambience. This was corrected with the 31SE upgrade. When I get the 31SE back from loan to a colleague, I will play this vs. the Callisto for JD when he comes back to my home to start the tweak process of my system.

And I had to laugh about JD rolling his eyes. There's always a wise guy! There simply has to be other "great" preamps out there. Jim White can't be the only designer to achieve such "qualities" like JD and I like so much from the Callisto. There are many A'gon members and other audiophiles I respect who highly praise the likes of the Atmasphere MP1, Lamm L2, VTL 7.5. And what about the top models from Audio Note, Jadis, VAC, etc.? Since I have not heard these in my system, or anywhere else, I am unwilling to give any absolute "best of" rating to the Callisto. All I know is that it stands head and shoulders above all the models I have heard.