Thrax Audio Ares Integrated Amplifier
Review by George Sallit
About a month ago I reviewed the Thrax Enyo valve/tube amplifier. https://www.hifiwigwam.com/forum/threads/thrax-enyo-integrated-amplifier.109701/ It would be true to say I was impressed with this upbeat amplifier and it certainly deserves to be considered one of the top integrated amplifiers in the £10-£15K group. However, if you are not keen on valve amplifiers and want to use a solid-state amplifier or if you want to forgo renewing valves Thrax also make a solid-state amplifier at a similar price. As it is a Thrax amplifier you would expect it to be different and it is.
The amplifier is built into a superbly machined case that needs the use of a complex multi-axis lathe to make. It is machined from a solid block of high-quality aluminium. The amplifier is unusual in that it is a Class A amplifier but does not use huge amounts of energy.
How do Thrax achieve that? Rumen Artaski the designer says “the Ares uses a so-called Hyperbolic bias. It is something the Japanese were working on in the 80"s and never quite got it right. In principle, it is a variable bias linked to the signal but the transistors never cut off. This is very important with bipolar transistors as the recovery of those takes quite some time and the behaviour is erratic at best and no amount of feedback will make it go away. One of the causes of "transistor' sound. So, our goal was to get rid of this problem from the root cause. Class A amps don't suffer from this but the heat and wasted power are immense. Making an integrated Class A amp would have been impractical at any power over 20-30W."
What are the key features of the Ares amplifier? The main amplifier has two true mono amplifiers with independent power supplies and transformers. It has zero global feedback It uses a non-switching output stage that is claimed to give a liquid Class A sound and texture without too much heat. It has a balanced front end with regulated supplies for the inputs and drivers. The volume control is via switched resistors. It has 3 RCA and 1 balanced input and an MC/MM phono input. There is an optional DAC board with a streamer that can play up to 32/768 kHz PCM and DSD. The Board is Roon Ready. It also has Bluetooth input. More information can be found at https://www.thraxaudio.com/ares.
It is a reasonable 430mmx450mmx120mm but weighs 27kg so take care when moving it around. It generates 120w into 8 ohms and 200w into 4 ohms. The Ares has a damping factor of 80 which is reasonable. Everything connected easily and there were no issues with getting the streamer working. I used my Audionote CD4.1T and Jays Audio CD2 Mk2 CD transports, a Melco N100 as a streamer via USB, the Ares fed my Audionote E Silver Signatures and a pair of Avalon PM1s. Mains cables were from Puritan and Quiescent mains blocks and Cut Loose Audio silver ribbon cables. The digital cables came from Audioquest. I let the amplifier warm up for a day or so before listening.
I played a few CDs and a test list from Qobuz to get a feel for how this amplifier sounded. And it sounded good, in fact very good. The overall frequency balance was neutral without any particular emphasis. The neutrality came with a very good 3D soundstage that showed if care had been taken in recording the music in a large arena/hall or when a soundscape had been cleverly crafted by someone like Eno or when a recording was dimensionally flat. Some amplifiers give huge soundstages for all recordings and do not have the differentiation of the Ares. It was now time for more testing music to see what the Ares could really do.
On goes Hans Zimmer 2049 which starts with powerful deep electronic bass. And this was ideal for the Ares as it had complete control of the bass and when the orchestra comes in there was a natural flow to the music that I associate with valves. The Ares completely avoided the staccato type of bass that plagues some solid-state amplifiers. Best of both worlds with control and flow in the bass. This allowed the orchestra to fill the soundstage without being modulated by the bass. A big 3D extravaganza of stirring music.
For something different, I played Strawberry Fields from The Beatles with its unusual stereo image and a young John Lennon. And then Space Oddity from a young David Bowie followed by Tom Jones with Dimming of the Day. These three tracks tested how the amplifier would deal with different (indifferent?) recordings and the naturalness of voices. The Ares rendered each of these very different singers in a totally natural way and presented each of them as a solid 3D image. No paper-thin images of the singers.
The astute amongst you, who read my review of the Thrax Enyo, will notice I am using the same tracks as I used to listen to the Enyo valve amplifier. That makes it easier to compare the two amplifiers, which I will do later.
On goes the really big stuff.
The Reference Recordings of Beethoven 9th. This was a ‘Professor’ Johnson recording that really captures the forces unleashed by the Pittsburgh Symphony Orchestra and Mendelssohn Choir of Pittsburgh. I, of course, had to play the finale. The power and dynamics were heard and felt through the Ares with real power to shock. And I have to say that the Ares had the edge with this music over the Enyo. The Enyo was big and powerful but could not quite match the Ares but it is better than most valve amplifiers I have heard apart from those at knee-trembling prices.
The four big bass tracks from James Blake, Limit to your Love; Chameleon from Anders Trentmoeller; Michel Jonasz with Le Temps Passe and Pictures at an Exhibition by I Guillou were next. Again, the Ares excelled in controlling the bass yet allowing it to musically flow and not dominate the music. The Avalons were in their element here.
As the digital board is the same as that in the Enyo, which I thought was well worth getting if you needed a good DAC and streamer. However, if you have a good quality separate DAC already, the board is optional so you do not need to buy it. Do not underestimate it though.
And now the comparisons. The Ares surprised me with how it sounded in comparison to the Enyo. I expected the Enyo, being a valve amplifier, to have a warmer balance and the Ares, being solid-state, to have a brighter, livelier sound. Wrong, the exact opposite. The Ares is neutral and flows like a valve amplifier. The Enyo is brighter and livelier. The Ares is not slow and sleepy, it is far too connected for that. Play 2049 or Beethoven's 9th Finale and be careful with your windows. It will rattle them if played loud. The Enyo on the other hand is not bright but really lively which is unusual for a valve amplifier. You can play it all day long (and I did) and it will not wear you out.
So, which is best? Depends on your system and what you want. I would say the only way you could decide would be with a good listening session and by a great coincidence that is exactly what Richard at Lotus Hifi does well.
Ah, but doesn’t he also sell the Vitus RI101MkII? Yes, and I have one here. In fact, I am playing it as I am writing this review. All these amplifiers are in the £12-15K bracket depending on what options you go for. Is the Vitus the disrupter? Not really. To make life tricky it is different to the Thrax amplifiers and the sound does not sit halfway between the two Thrax amplifiers. The Vitus is a powerful amplifier with 300w/channel and I would say it is a little more understated than the Thrax amplifiers. It has a subtle, detailed sound that is insidious. Insidious as in it gets under the skin when you listen to it and you appreciate what it is doing on longer listening sessions. The extra power gives the Vitus a more relaxed sound as though it is more cruising with the music but when I played the four big bass tracks it really delivered the sheer power, attack and drama in the music. It works really well with the Avalon PM1s, which being 4-ohm speakers mean it delivers closer to 600 watts/channel into 93db efficient speakers. You want loud, you got it.
So, I guess I have to finish by saying if you are in the market for amps at this price then you owe it to yourself to listen to these three and I would suggest that Richard would be more than happy to demonstrate them to you. They are good amplifiers and I welcome the newer Thrax amplifiers who have shown they can make great music without the need to rob a bank.