Review: Accustic Arts Reference Tube Hybrid DAC II DA converter


Category: Digital

This will be my third go around reviewing a DAC from the German company Accustic Arts. In between having the MK-3, MK-4, and now their Reference Tube Hybrid as my digital front end, I have had the pleasure to auditioned many of the highest regarded DACS and CDPS in the last couple of years. Many of this digital pieces offered great performance, a few were sonic "turkeys" regardless of some steller reviews, but based on great performance without having to get a second morgage to purchase it, I keep coming back to Accustic Arts.

The MK-4 was a significant improvement over the MK-3 and I still believe it's one of the finer sounding DACS around today. That's way I was skeptical about how much better/different would Accustic Arts new "baby" would be compared with their older DAC.

As in all my reviews I do not get into specifications, you can go to Accustic Arts website to get the details, but always comment on build quality and physical appearance. Like its older siblings the Tube Hybrid is just beautifully built and really is "eye candy". The German engineering and craftmanship is very easy to admire. I know one important technical aspect that this is the first DAC in the world that does not use tubes in the analog section, but somewhere further upstream when bits are still bits before the analog conversion stage. What the tubes are doing and how they are used in the overall design circuitry I don't have the foggist notion, just that sonic bliss is taking place.

When I discovered that Accustic Arts new reference would use tubes I was somewhat concerned for the following reasons: 1) My past experience with tube based DACS, such as the Zanden and a very high level Audio Note, was that they offered a very wonderful midrange but they lacked macrodynamics and extension on both the top and bottom ends. 2) The transparency/clarity and very small details I love in the overall sonic perspective of my system were lost.

SONIC PERFORMANCE

I do not like to result to sonic cliches to describe the sonics of a piece I'm reviewing, but this DAC is a "killer"! I hope all of us can agree that once you get to a high level of excellence in audio gear, their are many great pieces and differences become more quantitive then qualitative. We also have to factor in personnal taste and system synergy in to the equation. Taking all of this into account let me try to explain way this is the best digital I have heard in my system to the present time.

1) The Tube Hybrid retains all of the transparence/clarity and microdetails of the MK-4.

2) I will not say that the Tube Hybrid's extension on the top and bottom are better then the MK-4, but the the overall slam and dynamics is slightly more "lively" and natural sounding. Remember, the MK-4 was no slouch in these sonic areas to begin with.

3) Now we get into the specifics of why the Tube Hybrid is a "killer" in qualitative terms.

A) Unlike adding a "warm/euphonic" aspect to the music this DAC adds what many would call a touch of "bloom/fullness" without destroying the overall linear cohesiveness of the sonic perspective. Another more concrete way of saying it would be that image density and the overall harmonic structure ( leading edge, body, and decay trails) is more natural or what alot of audiophiles would dscribe as "analog" sounding.

B) This DAC offers an overall more sense of liquidity and smoothness, but not at the expensive of slam/punch/dynamics or sounding "soft" to be pleasing to the listener.

C) I have a hunch that another reason why the Tube Hybrid sounds more "real" is that it is more tonally linear compared to the MK-4, and any other digital piece I have heard on Redbook, which makes it sound of one piece top to bottom.

D) The Tube Hybrid offers the most natural timbres I have ever gotten from a digital front end.

E) I don't believe that my system's overall soundstage dramatically improved with the Tube Hybrid, the MK-4 was a champ in this area, but the layering and the air around players also went to a qualitatively higher level.

When I wrote a review here on the GON on the Stealth Metacarbon IC's I struggled to use words to describe the sound of "nothing", meaning these cables just get out of the way of the music so the illusion of real music being played by real people just gets spills into your mind and gut. Well, this DAC hits my sonic ear's the same way, it just sounds more like real music then I have ever heard in my listening room before. The Tube Hybrid sonics can be broken down into specifics, as I have tried to do, but its the overall natural/easy/lifelike sonic illusion without the loss of details,prat,sparkle that makes this a very special piece indeed.

I always end all my reviews with the statement their is no "BEST" in high end audio, but many fine pieces along with the factors of personal taste and system synergy. The new Accustic Arts Tube Hybrid DAC II is among one of the finest DACS on the market today, and while it is not inexpensive it competes with DACS triple its price. This German company sure has some talented thinkers with great ears when it comes to digital gear. If your in the market I highly recommend you audition this DAC before you purchase another.

Associated gear
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teajay
Teajay, Thanks for the info.

Regarding the Pass, I demoed not in my own place but at a dealers 2- X-350.5's with Swan speakers including Esoteric PO-3 combo and Hovland 200 pre. In the same system I heard the XA-100.5's and preferred them. I had the 100's in my system and compared to the X-600.5's and preferred obviously what I have but a fair competitor would be the XA-160.5's in which I will do.

It's looking good, my Dac is at customs so I should have it for the weekend.
Just wanted to share that I replaced the stock fuses in the Tube Hybrid DAC with Isoclean Power audio grade fuses. These fuses are quite a tweak, they significantly improved the overall sonic picture(transparency/dynamics/details/soundstaging)of the DAC.

I also finally put in my matched pair of NOS Telefunkens, instead of the NOS Amperex "Bugle Boy's". So far I find the Telefunkens seem to be more dynamic/transparent/detailed but are slightly less "sweet/warm" compared with the Amperexs. I like the way the DAC sounds with both sets of tubes, which are both quite better then the stock tubes from China, but have not decided which set of tubes I like more yet.
Well aren't you having fun, fuses and tube changing. Teajay I finally got my unit and all I can say is WOW! WOW!, your review says it all.

I don't think others really realize just how fantastic this unit is until they actually get one into their own system and they better be ready to pick-up their jaw from the floor.

I am looking forward to changing the tubes and fuses as you have but for now I'm just going to enjoy. I already picked up a match pair but will wait to install.

I exchanged my Supratek Sauv. line stage out of my system and put my ARC REF3 back in prior to putting in the Tube dac and defiantly preferred the REF3. but then I put the Tube dac in, I don't know if it's a synergy thing happening or what but I am just in awe with what I'm hearing.



Hi Dev, congratulations on your new AA Tube Hybrid DAC! It really is a terrific piece and I'm glad it lived up to what you were expecting. The MK4 is still a great DAC, however the Tube Hybrid goes to another sonic level.

I have come to a decision regarding which set of tubes I like more in the DAC. After another listening session with my dear friend Bob, who I refer to as the "Golden-eared" one we both came to the same conclusion, the Telefunkens offer power/dynamics/microdetails and finally unbelievable 3-D imaging in a very large soundstage which we both admired, but, he and I felt less "attached" in an emotional way to the music compared to the Ameperex Bugle Boys. The Telefunkens are not overly bright or etched sounding, however I think the word I would use to describe my experience of them in this DAC would be somewhat relentless and tonally cool, but boy on some types of music the balls to the wall dynamics and 3-D precise imaging was quite seductive, however the Bugle Boys for me sound more like real music with more natural timbres and an easy quality that allows you to relax into the music. Both tubes sound great in the DAC but different, and it really again comes down to personnal taste and system synergy.

Hi Teajay, here are two more tubes for consideration that were recommended to me; NOS Telefunken cira 1962 with rib plate and BRIMAR B.V.A. from England.

What is the correct size of Isoclean fuses?, what are your thoughts of HiFi Fuses I'm sure either would be better than the stock fuses. Have you also changed the fuses in your Pass amps?

I am still restraining myself from changing the tubes in the dac for right now even though I can't wait to do so, instead I'm just absorbing the musical upgrade over my MK4 dac which is a wonderful piece.