Review: Aesthetix Calypso Line Stage Tube preamp
Aesthetix Calypso Line Stage
There are two components that have created truly revolutionary improvements in my system. The first being the Plinius SA-102 Class-A, 125 watt power amplifier. The second arrived in my system four months ago, the Aesthetix Calypso Line Stage. This is a true breakthrough product in audio electronics, and I’m thrilled to have found it.
The Aesthetix Calypso is a relatively affordable ($4500) pre-amp. Considering all it has achieved in my system, not to mention the rave reviews and the 2004 TAS product of the year award winner, it could be considered a bargain. The Calypso is a merger of two long held audio philosophies not often successfully combined, solid state and vacuum tubes. The Aesthetix president and designer Jim White, was a chief designer at Theta, an often regarded leader in solid state audio circuitry. He began designing pre-amplifiers over ten years ago on the side, combining the latest revolutions in microprocessor-based control circuitry and vacuum tube amplification. The result was a hideously complex and astronomically expensive phono stage, the Io; and a Reference line stage, the Callisto. These incredible preamps use between 16 and 32 tubes each, and in their ultimate configuration, create a six chassis 270lb component preamp.
The Calypso has taken the lessons learned from these projects and created a one box, extremely simple but highly sophisticated line stage. (Note the Calypso has a sister unit for phone stage, it’s called the Rhea) The design begins with a massive power supply consisting of a high voltage transformer, heater transformer and a high voltage choke. All the magnetic components are shielded by a stainless steel cover. The power supply is regulated with a discrete transistor-based regulator. The Calypso uses only the highest quality components, including Roederstein resistors, RelCap film capacitors, Mercury Magnetics transformers and Nichicon audio grade electrolytic capacitors. My unit came with a complement of two Sovtek 12AX7WB and two 6922 vacuum tubes.
The Calypso is loaded with features and provides complete flexibility. There are five inputs, two outputs and a tape loop. The five inputs are accessed by five discrete buttons on the faceplate or through the very simple to use remote. Volume is controlled on the faceplate or though the remote. Balance is controllable by adjusting the volume level on either the left or right channel, when the two are set to the same level, the volume controls both channels simultaneously. There are mute and absolute phase features again accessible through the face plate or remote as is the bypass feature. When the bypass is engaged the unit’s unity gain is neutral, this allows for a home theater processor or other component to override the volume control. All inputs and outputs are available for either XLR (balanced) or RCA (single-ended) connections. When not playing music, the pre-amp can be put into “standby” mode allowing for all the electronics to remain powered up, except the vacuum tube plates. The only feature not available that some may wish to have is a mono switch.
My system uses the RCA connections. I should mention at this point that this unit is truly balanced. Looking inside the unit by easily removing the top (no tools required!) the design is amazingly simple and clean. There are two identical circuit boards sitting side by side towards the back of the unit. They are separated by a stainless steel “U” shaped trough that houses the power cord running from the back plate to the power supply located in the front of the unit just behind the faceplate. This “U” shape also is utilized as a structural element making for a more rigid chasse and thus less vibration. (This is brilliant in my mind. Placing the power supply and transformers in the front allows for short direct circuits working their way towards the rear panel and thus the outputs. So straight forward, but not something I’d seen before.) The tubes are easy to access and have ample room to simply remove and insert them into their sockets.
The long wait:
This unit has been a hot item over the past six months, and because of that, most of us who own one waited a fair amount for it to arrive. I was no exception, when I ordered mine the factory was six to eight weeks back logged, but I was able to catch a break when someone canceled their order, so I only waited three weeks.
During the wait time a friend of mine and I played a group of recording including the Minnesota Orchestra, female vocals like Lucinda Williams and Kasey Chambers, piano and vocals of Patricia Barber and Norah Jones, along with some favorite songs by Alison Krauss, Emmylou Harris, Sarah K. and Jerry Garcia. See later in the review for a detailed listing of recordings used during our audition.
I selected these recordings to test the “weaknesses and strengths” of my present system. First was the piano, I wanted a less electronic sounding piano. I was looking to duplicate the analog sound of a felt hammer hitting a tight string in a wood box. In my experience this is the hardest instrument for our systems to reproduce. My system was good with the Placette active line stage (old pre-amp) I had been using for the past three years, but on some recordings I sensed an electronic glare. Growing up with a mother who played a piano often, I am very sensitive to the poor reproduction that most stereos posses.
A second aspect of my system with the Placette that I hoped to improve on was the extreme high frequencies. Soprano singers in the top octave and violins were both every “excited” in my system. I would not term it as glaring, bright or harsh, but I would not term it as 100% natural sounding either. It possesses just a bit more energy than I like, leaving me feeling the system was just short of being annoying. It was not however fatiguing at all, so were talking a very fine line here, and something that over time I had “tuned” to an acceptable level through footers and isolation, along with room tuning. My hope for the new pre-amp was that it would retain the clarity and transparency, but at the same time back off the harsh “edge” of the high frequency threshold. So again, the music selected were pieces that pushed the limits of my systems ability on the raw edge of high fidelity.
Another aspect I hoped to improve upon was depth of soundstage. If my system had a weakness, it was in this area. I had once tried a pair of Cary 300B SET amps that showed me what was possible with my room. I have tried to recreate the sense of depth and definition in the soundstage that these magical amps created. But try as I might I never truly achieved that final “something” the Cary’s had produced.
These were the areas I hoped to improve on, but I was just as concerned that I not loose the 95% of what my system does right. Bass definition is flawless in my system, never slow or muddy. Always quick, focused and yet natural. Midrange on my system has always contained the same magic as the 300B SET amps, and I would not accept anything less. Definition is perfect. Transparency, clarity, pace and tempo are beyond reproach and again I was unwilling to lose even the most subtle bit of these qualities. Color, tone and timber are endless, natural and very neutral in their characteristics. For the most part, my system was perfect, except…
The final aspect of my system is emotion. I demand a system that allows me to “feel” emotion. This can be emotion created through an instrument, but for me its best presented through female vocals. I want to feel as though I can touch the singer, and comfort their pain. I want to see their tear or witness the curl of the mouth as they laugh. I want atmosphere, nuances so subtle that only the eighth time through the track am I able to truly define what I’m sensing. This is life played out through electronics, but never revealing itself as anything artificial, a facsimile of life being lived. This is perfection in two channel stereo, and this is what I expect to achieve.
My existing system:
A quick note on my system as it stood prior to the arrival of the Aesthetix. My system starts with a Sony SCD-1 (heavily modified by Richard Kern and Audiocom-UK) fed through a Great Northern Sound “Passive Audio Signal Isolator” into a Placette active line stage. I then have two Plinius SA-102 amplifiers bi-amped vertically. Meaning one amp drives the bass and the second amp the mid-range and tweeters. Both amps are played in true class A. The speakers remain Dunlavy IV-A. (No longer manufactured) All interconnects and speaker wires are Nordost Valhalla. Power cables include Nordost Valhalla (SCD-1), David Elrod ESP-2 Signature (Pre-amp) and NBS Statement (amplifiers). I use two dedicated circuits with 8 ga. wires, one for the amps and one to a Shunyata Research Hydra power conditioner fed by an Anaconda power cord. Both Circuits use Wattgate 381 outlets.
My racks sit on 4” sandstone slabs that rest on Aurios Pro isolators. Both my Mana (SCD-1) and Apollo racks are spiked to the slabs. Each component sits on a shelf “sandwich” comprised of 3/8” Aluminum shelves resting on upturned spikes from the rack. I then use a sheet of anti-static “Bubble Wrap” with a Neuance shelf sitting on the “Bubble Wrap.” The Hydra uses EAR feet between it and the Neuance shelf. The SCD-1 and both amps are supported by three Orchard Bay titanium cones (no longer available) and Aurios Pro isolators. The Placette sat on its factory footers, the Aesthetix sits on a “Tightrope” isolation system that in turn sits on a Neuance shelf “sandwich” The Dunlavy IV-A speakers sit on #3 Black Diamond Racing pucks and #4 BDR cones that then sit on Aurios Pros. Both the base and midrange/tweeter binding posts use Walker Audio High Definition Links II. All cables are raised off the floor using Cable Elevators
I use AudioPrism Quite-line system on the refrigerator, computer and T.V. outlets to cancel line noise at the source. I have home made acoustic panels in the vertical corners with triangle panels at the ceiling corners. I have one round home made acoustic column between me and an untreated window. Other windows are treated with Marigo window dots and wool curtains. The wood floors have thick wool rugs. I use an assortment of Walker Audio brass and lead pucks on much of the equipment and on two wood furniture pieces in the room. My SCD-1 has a ten pound ½” steel plate treated with s anti-vibration coating on its top and sides and a rubber sheet glued to the bottom. It then sits on four round rubber disks. (feet) The 14’-6” x 20’-0” room is used only for the stereo and is isolated from the house with French doors. The doors are covers by acoustic panels on the room side to reduce the glass surface. The house side of the glass appears as natural glass in that there is a dark surface behind the glass. The speakers are placed on the long wall approx. nine feet apart and 1/5 into the room. The listening chair is 1/3 into the room. Behind the listening chair is a teddy bear collection (acoustic bears) with book shelves on each side. There are a number of other “acoustic bears” that have been positioned in very specific locations to help focus the system. (REALLY!) Now you all have the evidence needed, I am certifiably nuts.
As you may have guest, I’m a bit anal when it comes to my stereo, but I must defend myself by saying this system is that sensitive. The tiniest change in footers or isolation can make a major difference in some tonal aspect of the presentation. A two pound weight on the top of a component might create focus that was not present before, or it might create a smear or pace change that is unacceptable. I tell you this not to show “how great my system is, or how crazy I am,” but rather to help demonstrate that when I’m talking about improving the existing qualities, I’m not discussing whole sale alterations. I’m only looking for the final couple percent. The minutiae of system synergy, the stuff I’d be willing to say most of the people even here at Audiogon would find overboard, not to mention the masses. My friends think I’m nuts to try to get more from my system, but they continue to drop their jaw when a new power cord is introduced, or when I went from MDF shelves to aluminum shelves as the bottom layer of my shelf “sandwich.”
So as you might have guessed, changing a major component is big doings, and the changes can be difficult to resolve without the proper audition method and enough time to understand what we are hearing.
The box arrives:
As I opened the well packaged 39 pound pre-amp and set it on it’s shelf I was pleased with its brushed aluminum faceplate, and clean simple design. It actually appeared to be the skinny brother to my SCD-1. Both have simple clean faces with a darkened plastic (LED readout) panel in the middle. It has a number of discrete brushed aluminum triangle buttons. (They look like little ‘A’s similar to their logo) I quickly reviewed the easy to read instructions and proceeded to hook it into the system. Next I put on my XLO burn in disc, track #9 on repeat, volume set low enough to not drive us all crazy; and I pulled the French doors closed, leaving the system to burn itself in.
Ten days; that’s my norm, ten days at 24/7 burn in before I begin listening. At least that’s the time I give before I make any type of evaluation. Ten days of waiting and waiting and waiting, but wait… What’s this? OK, I couldn’t wait, one day and I had to listen. I spent two hours with a very mixed impression. I was not impressed at all, so I thought I better wait a bit longer. Three more days passed, but I still had the same disappointment. As day nine came, 200 hours of time, it was time to try to figure out what was going on. A huge amount of hash/ tube rush noise. The noise was loud enough to really interfere on the quieter passages of music. I called the dealer and he sent a new set of Sovtek tubes overnight, but what the heck, noise and popping from the right channel. I tried mixing the two sets of 12AX7 tubes to find the quietest combination; as I waited for yet a third pair of tubes from the dealer. These were better, but not at all acceptable. One more set; this time from a different source; again noise and distortion.
I was frustrated, angry and extremely disappointed. I voiced my complaints to the distributor via e-mail and he quickly forwarded my comments to Aesthetix. I was impressed with the personal service, but all the service in the world will not make this thing sound better. I than started researching on Audiogon and Audio Asylum, quickly discovering I was not alone. There were three distinct paths people were taking. One was the “I’ll live with it “camp. In my overly sensitive system, this was simply not possible. The second route was send it back with a letter expressing my incredible anger and disappointment about lost time and money in shipping. The third route was tube rolling.
Cool, I’m a solid state guy, so tube rolling has always intrigued me, but I’ve never actually had the opportunity. (I should say I never tried it, I have owned Marantz, Conrad Johnson, and Kora tube pre-amps in the past) So as I most always do, I jumped in with all four feet. (Yes all four feet, I’m still a carnivore) I ordered one set of most every current production 12AX7, along with a select group of NOS tubes (New Old Stock). Believe me, I tried them all RCA, Tungsol, GE, Raytheon, Westinghouse, Telefunken, Phillips (Holland), Mullard, Siemens, Amperex Bugle Boy (Holland) and Brimer England. Each had a different and highly unique characteristic, although I tried to use only well matched low hour tubes to test, some were not perfect and thus my results were somewhat flawed. I began finding two things, no one tube had everything, it was more finding which tube set accomplished the most without giving up anything. The Mullard were very soft and warm. Phillips Holland was a bit to edgy for my taste. The Amperex Bugle Boy Holland (same plant) was excellent, but I was unable to find a well matched pair with low hours. The same can be said for the Telefunken, “maybe the perfect tube” but I could not find a well matched quite pair. The others were all lesser in many areas and were ruled out quickly.
Then I found an extremely rare, perfectly matched, very low hour pair of the Mullard 10M gold pin. This is the “cream of the crop” for the 12AX7 tube, and arguably the best 12AX7 ever made. The Mullard 10M gold pin, had every positive aspect of every tube I used; and to my ear it had no downside. To my wallet however there is a huge downside. A perfectly matched pair of NOS Mullard 10M gold pin tubes will cost $$$, and from the big reputable dealers well over $500. Needless to say, these tubes are extremely rare, but the results are beyond any expectation I had for this or any other pre-amp; and it brought my remaining components to levels I previously thought impossible. This was going to become an exceptionally exciting addition to my music enjoyment; but it was going to take a lot of work to fully integrate it into my system. Not only the time finding the right tubes, but it was going to require some subtle tweaking of the footers and room acoustics to find the best performance. Find it I did, and I will try to explain those changes and how this pre-amp differs from what I thought was as good as it gets when I was using the Placette. (I will not go into detail on the various tweaks we made, partly because I just don’t remember all of them)
I tried to describe the aspects I had hoped to improve upon above, now let me focus on the results. It’s wrong to focus on each minute aspect of the listening experience in that that is not how we enjoy music, but for the purpose of reviewing a product one almost has to focus on the micro before we can understand the macro.
Piano, remember this was my first priority to improve upon. Piano reproduction through a digital front end has never been completely satisfying in my experience. I’ve heard a great number of very high quality systems, but piano always has a glare of electronics. I’m not talking about an annoying level, just not 100% natural. I have heard quality piano reproduction on analog systems, but at the cost of the downsides of analog. The Aesthetix with the 10M tube is 100% right on. Every note in every octave is natural and clean with the accurate quality of resonance as notes decay within the space. A warmth on the midrange and a shimmer in the higher octaves all sound as I know a real piano to sound. AMAZING, simply amazing! I’ve pulled out disks that before were fatiguing and/ or electronic sounding only to discover an enjoyment beyond reproach. Now I’m not about to tell you poorly recorded piano suddenly sound natural and analog, no they still sound like crap, only softer. Patricia Barber and I have fallen in love all over again, now with a new fondness of her immense talent. Every subtle nuance of her piano comes across as if she were in the room. A muting of the strings by the foot pedal comes through as if I were seeing it with my eyes.
As far as soprano vocals and what might be considered harsh un-listenable high octave vocals, well they now have body. They remain unsightly high and transparent, but there is a wholeness to these ultra high frequencies that make them real and human. Some of my favorite vocalists, Emmylou Harris, Kasey Chambers and Alison Krauss are real, not harsh in the slightest, but defiantly not warm and fuzzy either. Their simply real, natural and extremely emotion filled. The violin, another “voice” that is known to create problems for digital systems to accurate reproduce, sounds like a string and wood instrument. The warmth of the violin’s wooden body is present through even the highest notes produced. “Stradivarius on Gold CD“ has always been a good disk to test the system with, but the piano and violin together can be a fatiguing experience if the entire disk is played front to back. Not now, it allows me to enjoy the instruments as I would in a well designed symphony hall. “It’s just lovely, glowing and crisp.”
Yea, yea, yea. The world is now perfect and the weather is always sunny and 72 degrees; in Minnesota no less. No I’m not going that far, but the Aesthetix with the Mullard 10M 12AX7 tube in my system is as close to perfect as I could ever expect to achieve. I lost none of the transparency I received from the ultra clean Placette. The tempo matched my expectations, meaning perfect, but tube selection did largely affect the tempo and pace; with the standard Mullard tubes being sluggish. The 10M and the Telefunken were every bit as right as live music, and every bit as good as my old system.. The bass remains tight, well focused and to my surprise not at all slowed or muddied. The soundstage is amazing! The detail and focus is laser clear but not at all artificial. I can see much deeper into the soundstage and find definition with instruments set behind others. The three-dimensionality is every bit as good as I remember the Cary’s to be, but with better focus.
A quick look back:
The major strengths of my system, the Sony SCD-1, Plinius SA-102 amps and Dunlavy IV-A speakers are their combined ability to accurately reproduce music. The sudden attack of the lead edge of a note, through the subtle decay as the note fades from our ears is as close to live as I’ve found possible. The Placette pre-amp was the perfect fit in that it is invisible; it is so transparent and so neutral that it adds nothing, thus allowing the qualities of my other components to be heard. The “weakness” of my system is in my cabling; they are so revealing and so demanding that even the slightest flaw in the components is brought to light. Some people claim the Valhalla cables are lean, or overly bright, and frankly that is true, but only because of the weaknesses (or characteristics) of the components they are attached to.
I understand the contradiction of my statement above. I’m calling the absolutely crystal clear Valhalla’s a weakness and the “flaws” of my components the strengths. In fact this is not a contradiction, for every component made is flawed in some way, perfection comes when a synergy of components counter balances each others weaknesses creating a balance of sonic qualities. So with the ultra clean, ultra transparent, ultra neutral personality of the Placette, my system ran on the edge between bright and edgy and well reproduced high frequencies. My system was not ever fatiguing or objectionable, but it was always right at that edge. I learned to tame my systems potential through footers and tweaks making it very enjoyable, but at the same time taking something away from its ultimate abilities.
Now I’ve replaced the Placette with the Aesthetix line stage and after resolving some tube issues I’m more in love with my system than ever. All the qualities I described in the prior paragraph remain, but now something has been “added” to make it more whole, more real and human. Yes I said “added” for there is no question this pre-amp is adding its own sonic signature (if only through the tubes). It is not neutral like my past pre-amp, but it’s a good thing. The sonic qualities match my other components perfectly; each apparently strengthening the other to climax in what I believe to be as real a presentation as possible with today’s electronics. Not only does it appear to mate sonically with what my system is trying to achieve, but the “added” weight, body, sole or whatever we call it has filled in the thin areas of the Valhalla cabling. No longer do I sense any of those comments about thin, dry or bright. They are simply crystal clear and faster than superman on steroids.
This may be the best place to address one concern regarding system matching with the Aesthetix. I have heard a lot of people express problems (or wondering if they will have problems) in matching the output impedance which is 300 ohms SE and 600 ohms balanced, with a recommended load of >50K ohms. My amps input is 100K ohms, and in theory might create a matching problem. I have little knowledge of what I just said, but I can tell you it is not an issue in my system. For the record, the absolute phase input impedance is 40K ohms SE and 80K ohms balanced. Maximum input is 3.5v (SE), 7.0v RMS balanced.
Musical interpretation and impressions:
So you’ve been asking yourselves for the past few minutes; why the odd eclectic music selection for the listening/ auditioning sessions. I will clarify that now. Below is a detailed list of the specific cuts we used during our many nights of auditioning. Every night we played all of these for the specific reasons described below. It is possible to skip this section if you do not want this level of detail.
Copland 100; Eiji Oue conducting the Minnesota Orchestra. Reference Recordings
Track #1 Fanfare for the Common Man
It should be noted that the two Minnesota Orchestra recordings were used because we both know Orchestra Hall in Minneapolis and have heard these selections live in the Hall where they were recorded. Our criterion was to attempt to duplicate the experience of being in the Hall itself. Bass! The quality of the bass kettle drums leading edge note and the reverberation and decay through the hall was all we were looking for here. The result was excellent, the scale of the image is huge and the reverberation time was right on.
Mephisto & Co; Eiji Oue conducting the Minnesota Orchestra, Reference Recordings
Track #4 Mussorsky; Night on Bald Mountain
We were looking for the complex congested passages that combine with extreme impact and attack over the course of this track. From the piccolo through bass kettle drum during full orchestral crescendo, each section of the orchestra was clear and visible. The test was to see how the system was able to resolve all the information and retain realistic imaging and impact of the bass kettle drum. Never has my system been so close, it is possible to close your eyes and transform the mind to the Hall itself. One issue, my system places you in row ten, but due to the parents I have, I am not privileged enough to have inherited those seats, thus the previous track, “Fanfare for the Common Man”. In other words, row 63, far right!
The Pizza Tapes; Jerry Garcia, David Grisman and Tony Rice
Tracks # 5- Shady Jam and #6- Shady Grove
I just love these two tracks and the midrange qualities of two guitar greats and the best mandolin player is wonderful. I learn nothing other than the midrange and imaging is as good as ever.
Patricia Barber; Café Blue. SACD
Track #4 Romanesque
Vocal and midrange purity, this track must sound analog and natural and it did.
Track # 11 Nardis
Here I’m looking for piano qualities and imaging of soundstage. I was listening for the attack of the lead edge of notes, transients, rhythm and pace of drums and piano.
Patricia Barber; Modern Cool, SACD
Track #4, Constantinople
I was looking at a number of issues here. Bass definition, imaging and emotion with the bow on stand up bass. Clarity and imaging of percussions were far better than I’d had before. The brass horn needed to be brash, crisp, sharp but not glaring or harsh. Wow, it was better than live.
Track #11 Postmodern Blues
It’s all about bass definition, attack and impact.
Lucinda Williams; Essence.
Tracks #3 I Envy the Wind, #4 Blue, #6 Are You Down, #8 Reason to Cry, #11 Broken Butterflies.
OK, I have a love affair with Lucinda, and have seen her live in local intimate clubs. I know her live and I know her recordings. Lucinda is all about emotion, imaging of pain, intricate vocal qualities, subtle inflections that create a mental image. EMOTION! Damn she’s got it here. My system is so liquid, so musical and so detailed. I can truthfully say, Lucinda is more enjoyable on my system than live. I can make the same comment regarding Patricia too, which I have also seen in local clubs. The Aesthetix has transformed my system to pure magic.
Kasey Chambers, The Captain, Import 1999 EMI Music Australia (huge sonic improvement between import and domestic release)
Tracks #3 This Flower, #5 These Pines, #7 Southern Kind of Life.
Kasey Chambers; Barricades and Brickwalls. Import 2001 EMI Music Australia
Tracks #2 Not pretty enough, #7 Million Tears, #11 Falling Into You.
If you’re not familiar with Kasey, you’re missing something very special. She is a young untamed soprano Lucinda Williams. Her emotions are pure, raw, on the edge and extremely involving. The sonic qualities of her domestic recordings are in my opinion un-listenable, but her imports are quite clean. Her voice is edgy and at times painfully bright through my Placette, but perfectly honest and raw through the Aesthetix. This is why I love music, the emotion and drama; it’s pure and perfect with the Aesthetix.
Emmylou Harris; Spyboy.
Track #1 Songbird
Air, atmosphere, transparency and presence, these are adjectives I would use to describe the voice of Emmylou. I again am amazed at what I’m receiving from my system.
Alison Krauss + Union Station; New Favorites. SACD,
Tracks #1 Let Me Touch You for Awhile, #7 I’m Gone
Alison has a very airy pure voice and her band is large and complex. Pulling all this together and yet retaining the delicacy of Alison’s voice is not that much to ask, yet to make it “life like and alive” is another thing. The Aesthetix again has added a wholeness to these tracks, bringing life where there was non before.
Norah Jones; Come Fly with Me. SACD
Track #3 Cold Cold Heart
This is simple; the piano has always appeared a bit “hot” in my system. Now it has body, pure and natural tonality and amazingly clear detail.
Sara K; Hobo
Tracks #3 Brick House, #7 Oh Well, #8 Hobo
It was fun to bring out this old favorite. This recording is so good and clean that it’s always sounded great. What I looked for was depth and imaging, along with a sense of space. On Hobo, there are a number of solo voices of instruments (harmonica, triangle and shakers) that have always been present, but now they have three-dimensional form and location within the soundstage. The triangle’s crystalline qualities are sudden and pure with a decay that lasts forever; it’s just simply amazing.
What more could I possibly say. This line stage stands alone in a very congested category for audiophiles’ toys. This is not a tube pre-amp, it’s much to fast and transparent for that. The bass is far to defined and solid to be tube, the attack is far too sharp to categorize this unit with any other tube product. But wait, this is clearly not a solid state transistor based pre-amp. There possesses far too much body and tonal richness to be transistors. There is fullness; a humanness that is simply not possible with solid state products. The detail is there, but the edges form a true three dimensional image, verses the solid state two dimensional razors edge. The transient attack is something only solid state can create, but the holographic imaging is only possible with tubes. I can tell you; the Aesthetix Calypso is perfect!
But that is not quite true, sadly this review is not of the stock unit, but of a unit with a very rare, and relatively expensive Mullard 10M Gold Pin, 12AX7 tube set. I can not tell you how the stock unit sounds or performs; because after four sets of Sovtek tubes, I never did find a quite, not micro phonic matched set. I wish I could tell you the unit you receive out of the box is all mine is, and it may well be. I just can’t share that experience personally. I can say this could be the perfect pre-amp, and it may well be straight out of the box, I simply do not know. I have been told by my dealer and the distributor that there was a bad batch of tubes that came through, and that problem no long exists. Well if that’s true, thank God that’s over. Sadly I know a lot of potential customers moved on frustrated and left with a very bad taste for Aesthetix products.
Lucky for me I believed all the high praise, and found a way around a bad tube batch. I hope for the sake of all of us the Sovtek tube (Please read comments from the manufacture below to learn how they resolved this issue) does all my unit can do, if that is true, this is the last line stage you may ever own! If it requires NOS tubes to create the ultimate magic, it will still be the last line stage you’ll own. It is perfect!
Thank you for listening, J.D.
I emailed a draft of this review to the distributor who in turn forwarded it on the Aesthetix. Lucky for all of us, the president and founder of Aesthetix took the time to help us learn how the tube problem arose, how they solved it and the enormous quality control they employ at the factory. Please take the time to read his response.
Dear Mr. MacRae,
Thank you for the detailed and insightful review of the Calypso, and your tremendous patience!
Regarding the tubes, a bit of history:
I originally designed the Io around the Sovtek 12AX7WA, then went to the 12AX7WB when it came out, because I thought they sounded better. For many years, the Io was sold that way, with very few problems with the 12AX7WB. When I set out to design the Calypso, I based its gain stage around the same tube, based on that past successful experience. The operating conditions are identical to that used in the Io (plate voltage, plate current, etc.) For about the first 6-8 months of production, we had almost no tube problems with the Calypso. Then, they started cropping up, as noise like you encountered. This was our worst nightmare, because we thoroughly evaluated the units before they shipped. They were going noisy after leaving our facility. We immediately started burning the tubes in longer and testing more thoroughly and stringently, but with little success. I looked into alternatives, but no tubes of current manufacture worked properly or to my satisfaction, so we stayed with the Sovteks and continued trying to find ways of culling tubes that would go noisy. Near the end of last year, we finally found a 12AX7 of current manufacture that sounded good and would remain noise free. We have since switched to that tube (Teslov E83CCS), and our tube noise issues have been drastically reduced.
Every tube that we use is tested. First we test them at the same operating conditions that they will be used in our units, and write down the pertinent characteristics. Then, we go through and match the tubes for gain and other parameters. They are then installed in production units and again tested for noise, matched gain and other operating characteristics. Next, the units are burned in for 100 hours and we evaluate the noise a few times during this period. Then there is a final listening evaluation that includes noise testing. The same basic procedure is used if we are replacing tubes in the field.
One aspect of all of my designs that contributes to more demands on the tubes is that I do not use any form of global negative feedback, as I believe it is damaging to sound quality. Feedback greatly reduces noise, distortion, tube matching requirements and output impedance. If the Calypso had global feedback, many of these tube problems would not have exhibited themselves. It is my decision that it is worth the pain and trouble to test and match tubes to achieve the sound quality described in your review.
As you wrote, the Calypso is a simple circuit. It basically consists of input switching, volume control, gain stage (12AX7), output stage (6922). Therefore, anything that happens in the 12AX7 goes directly to the power amp and will be heard.
Thank you again for your wonderful review, I enjoyed reading it.
Sony SCD-1 (heavily modified by Richard Kern and Audiocom-UK) Placette active line stage
Two Plinius SA-102 amplifiers bi-amped vertically.
Dunlavy IV-A speakers.
All interconnects and speaker wires are Nordost Valhalla.
None I know of