Thrax Libra - A Statement Preamplifier and A Game Changer

Hi Ron,

Prior acquiring the Libra, I had the opportunity to listen to an Aries Cerat preamp in my system thanks to Flyer who is close friend and who used to be the local distributor. It was way too coloured to my taste.

I compared the Libra against the darTZeel preamp. I much preferred the Libra.

I never had the chance to listen to NAT or Trafomatic. I will never purchase a component that I cannot test in my own system. This somehow limits the choice as I am only working with two highly trusted brick and mortar dealers: Ana Mighty Sound in Paris and Noir & Blanc in Brussels. At least, I am sure that I am making a fully informed decision and that I will get a top notch customer service.

Beside, I wanted to have a fully balanced tape loop and only the Thrax Libra is offering that feature.

Kind regards
 
Hi Ron,

Prior acquiring the Libra, I had the opportunity to listen to an Aries Cerat preamp in my system thanks to Flyer who is close friend and who used to be the local distributor. It was way too coloured to my taste.

I compared the Libra against the darTZeel preamp. I much preferred the Libra.

I never had the chance to listen to NAT or Trafomatic. I will never purchase a component that I cannot test in my own system. This somehow limits the choice as I am only working with two highly trusted brick and mortar dealers: Ana Mighty Sound in Paris and Noir & Blanc in Brussels. At least, I am sure that I am making a fully informed decision and that I will get a top notch customer service.

Beside, I wanted to have a fully balanced tape loop and only the Thrax Libra is offering that feature.

Kind regards

Thank you very much for your detailed reply! Your policy about never purchasing a component that you cannot audition in your own system makes perfect sense to me!

Merry Christmas!
 
I listened Lybra many times from Italian distributor and for me is absolutly one of the best preamp i never listened,very natural and magic mid
 
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I listened Lybra many times from Italian distributor and for me is absolutly one of the best preamp i never listened,very natural and magic mid
Hello Gian!

Merry Christmas!

Did you ever have occasion to hear it side-by-side with another preamp?
 
Hi Ron,

Prior acquiring the Libra, I had the opportunity to listen to an Aries Cerat preamp in my system thanks to Flyer who is close friend and who used to be the local distributor. It was way too coloured to my taste.

I compared the Libra against the darTZeel preamp. I much preferred the Libra.

I never had the chance to listen to NAT or Trafomatic. I will never purchase a component that I cannot test in my own system. This somehow limits the choice as I am only working with two highly trusted brick and mortar dealers: Ana Mighty Sound in Paris and Noir & Blanc in Brussels. At least, I am sure that I am making a fully informed decision and that I will get a top notch customer service.

Beside, I wanted to have a fully balanced tape loop and only the Thrax Libra is offering that feature.

Kind regards
Hello dcc, many thanks for sharing your thoughts. Would it be possible for you to share your impressions on the differences you observed between the Libra and Dartzeel preamp? Were they used with the Dartzeel and Thrax amps? Would appreciate any thoughts you could share. Many thanks
 
At AMS, I was able to make a direct comparison between the darTZeel NHB-18NS/NHB 468 combo and the Thrax Libra/Spartacus combo as well as using the Thrax Libra with the NHB 468. We used identical cables.

IMG_5305.jpeg

With the NHB 468, I found that the Libra was more "open" than the darTZeel NHB-18NS with some more dynamics.

Overall, I preferred the Thrax combo over the darTZeel one. This led me asking François to bring the Spartacus to my place but also the top of range Phoenix. I eventually ordered a pair of Phoenix.
 
At AMS, I was able to make a direct comparison between the darTZeel NHB-18NS/NHB 468 combo and the Thrax Libra/Spartacus combo as well as using the Thrax Libra with the NHB 468. We used identical cables.

View attachment 141851

With the NHB 468, I found that the Libra was more "open" than the darTZeel NHB-18NS with some more dynamics.

Overall, I preferred the Thrax combo over the darTZeel one. This led me asking François to bring the Spartacus to my place but also the top of range Phoenix. I eventually ordered a pair of Phoenix.
Wonderful. Many thanks for the feedback. Enjoy your new amps.
 
Hello Ron,
Marry Christmas also to you and all this beautiful forum
I compared Lybra only with Thrax Dyonisio,Lybra more natural
My friend distributor has Thrax,Wilson benesch,Kalista;Metronome,DS Audio
 
At AMS, I was able to make a direct comparison between the darTZeel NHB-18NS/NHB 468 combo and the Thrax Libra/Spartacus combo as well as using the Thrax Libra with the NHB 468. We used identical cables.

View attachment 141851

With the NHB 468, I found that the Libra was more "open" than the darTZeel NHB-18NS with some more dynamics.

Overall, I preferred the Thrax combo over the darTZeel one. This led me asking François to bring the Spartacus to my place but also the top of range Phoenix. I eventually ordered a pair of Phoenix.

On this comparison at Anamighty I preferred both Thrax pre and power individually as well as a set to the darts. By quite a margin.
 
Thrax is know for unconventional amplifier topologies and implementations, so here is the story of the latest amplifier in our portfolio. Few years ago I wanted to replace an aging Wavac HE-833Mk2 with something more manageable and with better low end. So I set to design the ultimate Single ended triode amplifier as proof of concept of a new topology and driving method removing the constrains and sonic influence of coupling capacitors and inter-stage transformers. The amplifier featured a Western electric 212E output tube operating at 1600V delivering 75W of pure class A triode power with no coupling capacitor or inter-stage transformer used. The amplifier has only one more triode in it’s construction to achieve solid-state like distortion figures and noise.
This was the culmination of our engineering capabilities and certainly very satisfying but commercially absolutely a no go. At those voltages the paper power capacitors and insulation materials where ridiculous in cost and bulk. The output transformer was enormous. And most of all the 212E tube is not really available. The Chinese copy was ok but far from the sound of the NOS tubes. So thinking of ways to scale this to more manageable voltages we quickly run out of contender tubes if we where to keep to similar power level.

Having acquired some Tokin static induction transistors years ago I remember they operated at up to 600v with power dissipation of more than 400W and trying them seemed like a viable choice to replace the 212E tube. The Tokinn SITs are essentially solid state triodes. Then the problem moved on finding a suitable tube for the driver. Here again we ended up in a dead end with only the WE 416B/C fitting the bill in gain and voltage swing but no availability. That worked well until we could not secure more than a dozen. This is the point where the project was almost scrapped had I not seen in the junk on my desk some Russian static induction transistors from 1989. We played with them some years back and they where so bad that the crystal will just fall of the TO3 base when thermally stressed. Anyhow I remember that parameters seemed to fit the main requirements for this new topology so there was nothing to loose replacing the 416b with the Russian unobtanium part. It worked with no smoke on the bench.

Quick measurements confirmed stable operation and we quickly moved the amps to the listening room to confirm there is no strange behaviour or instability. First couple of notes trough the amps had the effect of a smack in the face with a shovel. You know something big is happening but you have no idea where it came from as your brain is buzzing. It was so radically different and realistic that we started looking at each-other to confirm the experience we shared. Nothing, there was nothing other than exquisite music in the room, no artefacts, like the amp was not there at all. Four hours later we where scrambling to find all the leftover parts on the Russian and Ukrainian internet stores. Five here, ten there and at the end of the month we secured about 100pcs. with some more available enabling us to consider a limited run.

The Phoenix name is no coincidence. The amplifier features a technology that is no longer used with an implementation that brings out the unique qualities of those devices that was never really appreciated in full until now.
Everything about the amplifier is against the mainstream. It is all solid state, but it is with transformer coupled output. It is with tube like simplicity yet it is auto-biased with full DC coupling.
It is the ultimate single ended triode replacement where there is only one gain stage.
It uses 2 static induction transistors forming a single gain stage in patent pending implementation. Giving exactly what you would expect from a directly heated triode single ended amp with none of the shortcomings like microphony, limited power or filament noise.
To make sure we are not just having a tripping episode I acquired a sample of all commercially available V-fet amplifiers from Yamaha, Sony, JVC and Hitachi (still missing only a Sansui and a DigitaldoMain sample). This confirmed that the V-FET is key to the sound but implementation is even more important and what we had is unique.
At that point it was obvious that this has to be shared with the audiophile community and that the lucky few will have the opportunity to enjoy their music like nobody else.
Phoenix will be produced only to order and the run is limited to 25 individually numbered pairs only. The amplifier uses the same chassis as our Spartacus 300.
The Phoenix has risen…..at least for a while!
 
Great story, and a nice lead in to a high price product !:rolleyes:
 
DCC, your room is one of my favorite rooms, and it's always fun to see what gear is in residence.

For some reason, Thrax never gets the love that the big Swiss brands do. That is a shame because I have heard their gear often, and they can run with the best. Some on the forum do not believe products from Eastern Europe can be compared with those from the US, Germany, Switzerland, and Japan, which I politely disagree with.

Happy Holidays, everyone!
 
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I have Yatrus,Dionysos,Heros MK II,Lyra with Hades

In 50 years of my experience i seldom listened something little better,Lyra and Heros mk II are shocking

Cannot imagine Lybra with Phoenix
 
On this comparison at Anamighty I preferred both Thrax pre and power individually as well as a set to the darts. By quite a margin.
Why, exactly? What were your sonic impressions of the combinations? And of Thrax Spartacus versus darTZeel 468?

Thank you.
 
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On this comparison at Anamighty I preferred both Thrax pre and power individually as well as a set to the darts [darTZeel]. By quite a margin.
With the Stenheim Alumine Five speakers, I guess ? (Alumine Five, or Alumine Five SE ?)
Why, exactly? What were your sonic impressions of the combinations? And of Thrax Spartacus versus darTZeel 468? [...]
+1
 
Hi Ron,

Prior acquiring the Libra, I had the opportunity to listen to an Aries Cerat preamp in my system thanks to Flyer who is close friend and who used to be the local distributor. It was way too coloured to my taste.
[...]
[please forgive my poor English]

This is interesting.
I found it more "colourful" indeed, life-like and "natural" than my (very good) solid state preamp, which sounded unnaturally bland in comparison, with live concerts in mind (details hereafter).
But YMMV, as they say across the Atlantic.
I am a huge fan of Thrax too ;-)



Initially, I owned a very transparent solid state YBA 1 preamplifier, with separate power supply (PS) and good phono input. It was almost by chance that I was offered to try an Aries Cerat Incito at home for a whole week (Incito non-S, embedded PS). I had very strong prejudices against tubes, which I knew little about: "rosy view" of the real thing, they sound veiled, mellow in the bass, colored, they lack of details, reliability, maintenance is a headache for a non-technician, they generate heat, warm-up is required - my YBA could be left always on -, etc. Nevertheless, I gave the AC Incito a try, just out of curiosity, being 99% sure that it was pointless compared to my YBA 1.​
(I was emphatically urged by the lender to also compare the Incito with the Audio Research Ref-xx at the time (ref 5SE? ref6SE?) and a Pass XP20. It was not possible)​
With the Aries Cerat Incito, I was instantly stunned by how much more direct and "life-like" the sound actually was. I was struck altogether by the enhanced presence of the instruments, the deeper, much wider soundstage, the much better dynamics, and, above all, by the much more colorful rendition indeed, which better saturated timbres, but with no exaggeration for my liking, as if they had better kept their natural "density", were better "texturized", making the whole thing sounding closer to live concerts I attend regularly. It was a bit like coming from a painted fresco with faded colors (my SS preamp), covered with age-old patina, to a scientifically restored Quattrocento fresco, with genuine and vivid colors (tube preamp). A bit like attending a concert sitting in row J of the historical, elliptical concert hall of the Fine Arts Center in Brussels (good to very good acoustics), then attending the same concert, same program (because I'm fond of it), same musicians, the day after, row J too, but in a state-of-the-art newly designed shoe-box concert hall (Namur Concert Hall, now one of the best in Europe, especially for ancient and vocal music, inaugurated in 2021, designed by people who worked on the Philharmonie de Paris). That contemporary shoe-box concert hall delivers high levels of transparency and details, but also more "timbres variety", with better density, better body, and flesh to the instruments, also on orchestral works (for instance, this was immediately obvious with the bassoon at the beginning of Mahler #1, also in Mozart violin #5 - it happened that I did that unsettling and refreshing experience; living in a country as big as confetti has some advantages: the first, elliptical concert hall is 9 metro stations ahead, the shoebox is 3 train stations ahead). In the first, historical hall by comparison, it is a bit as if timbres and "tonal density" (sorry for my English) had kind of partly "sublimated" (transition from the solid state to the gaseous state). I attended dozens of concerts in both halls now (maybe hundreds in the historical one?); the Antwerpen Elisabethzaal hall is also great btw (just don't sit too far away). These concert halls are my aural compas, especially the Namur Concert Hall and the Antwerpen hall.​
By contrast, my SS YBA 1 sounded bland and "colorless" in comparison. In the first bars of the first piano sonata I heard, I had bought the Incito... I did not expect that at all initially. It transformed my humble system.​
(and regarding my initial prejudices against tubes: the tubes used in the preamp last thousands of hours, and are cheap, even if they are sold as paired by the manufacturer; that tubed preamp turned out to be the most stable and reliable audio component I have ever had, nearly seven years without a single hitch).​
There are also many other variables, I guess. We are all different listeners. My context is also very different: I listen much closer (mid-field) to my speakers than you (4m ?). At a much lower volume (neighbors), with a much more humble gear.​
Additionally, all Aries Cerat (AC) preamps are single-ended circuits. You had Krell and Tenor Audio power amplifiers at that time, which are both fully balanced circuits. Could it be that the match may have not been optimal with a single ended AC preamp? (I read it is advised not to use ACs preamp with their pseudo-balanced outputs, if any; at least the best result should not expected that way; but I'm sure Flyer knew what he was doing when he tried AC preamp at your place)​
I listened to their first, most affordable preamp; you probably heard a model which sits much higher in the range.​
I also had much less requirements than you regarding functionalities (I needed neither fully balanced circuit as my amp is single ended, nor two outputs for bi-amping, nor balanced tape loop, etc). And I had much less expectations regarding quality, given my modest system (to WBF's standards at least); I actually did not expect anything at all from a toob preamplifier...Rougly, I am a much less demanding amateur.​
I wish to add that I am a big Thrax admirer since I have listened to the Lyra speakers (non-SE version, which is said to be much better still). I am sure that the Lyra and the Phoenix monoblocks lead your system to new heights. The Lyra was already in your system when I heard it last year (bi-amplified with the Krells and Tenor audio, before the speaker setup made by Sterling Trayle). To me, the system at that time was already one that verged towards what I consider to be the best concert halls and seemed exceptionnally promising (as a work in progress).​
Needless to say that I am eager to enjoy your very last upgrades in January (especially with that wonderful tape of the Mozart piano concerto #20, Clifford Curzon piano, conducted by Benjamin Britten, that you had played on the Studer last time; and you seem to own an even better device for tape playback now... gulp !)​
 
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I believe that the AC preamp was not a good match with my fully balanced electronics. We tried several rectifier tubes but it did not help either.

The Studer has been further upgraded since your last visit and I can tell you that the Mozart Piano Concerto No 20 sounds better on the Studer than on the TP-1000.
 
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