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

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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.