Thrax Libra - A Statement Preamplifier and A Game Changer

[dcc]

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

 

[Ron Resnick]

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!

 

[gian60]

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

 

[Ron Resnick]

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?

 

[ashandger]

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

 

[dcc]

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.



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.

 

[ashandger]

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.

 

[gian60]

What is the Phoenix?

 

[gian60]

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

 

[dcc]

What is the Phoenix?

More details about the Phoenix in this thread: https://www.whatsbestforum.com/thre...-phoenix-from-thrax-audio.39866/#post-1016865

 

[bonzo75]

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.

 

[Rumen]

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!

 

[Lagonda]

Great story, and a nice lead in to a high price product !

 

[gleeds]

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!