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
Click to view my Virtual System
teajay
On the website, Postive Feedback Online, reviewer Marshall Nack just posted his review of the Accustic Arts Drive 11 and the Tube Hybrid DAC 11 SE and stated, "At its price point, it is the best I've come Across". For the details of why he came to that conclusion read Mr. Nack's review, but for us that own the AA Tube DAC 11, the SE version costs $500.00 gives you better tubes and a few upgraded parts, but basicly sounds the same as the regular DAC 11, we know already that it's still one of the best sounding redbook DACS and competes with virtually anything out there regardless of price. I'm glad a good reviewer, in my opinion, here in the states finally is giving the Accustic Arts gear some well deserved credit.
Hi,

I am currently using AA Drive 1 MK1 + DAC 1 MK2, and consider to upgrade to Drive 1 MK2 + DAC 1 MK4. Will Drive 1 MK2 + DAC1 MK4 sound more mechanical and hifi compared with Drive 1 MK1 + DAC 1 MK2? I just a bit worry abt the this upgrade will cause the sound too forward and not natural enough!
Cykeric, the short answer is no, it won't sound too forward and not natural enough.

Read my review of both pieces for the details why both pieces, Drive 1MK2/DAC 1MK4, will be an improvement sonicly over the prior generation.
Thanks very much Teajay.

However, your review is on AA tube dac and the comparison is on AA tube dac with MK4, not MK1/2 with MK4.
I notice there are 2 versions for tube DAC II. One is tube DAC II ref, and the other is tube DAC II SE. Which one is more updated?? The outlook is also diff. One is without "tube" wording on the top, and the other is. So, which one is SE and which one is ref?? Thanks.
Cykeric, I'm a little confused, I did GON reviews on both the DAC 1-MK4 and the Drive 1-MK2 which compared them to the first generation AA pieces, not the Reference Tube Hybrid DAC. Take a look at them, if you have not already.

Regarding your question about what is the difference between the tube DAC 11 and the SE version, the SE version uses some higher tolerance parts and supplies you with what are called special "NOS quality tubes". Well, at least the SE unit I heard came with JJ 12AX7 tubes, which ain't special, not NOS and sound like crap. The sonic difference between my DAC 11 and the SE version was my DAC sounded better with the tubes I use, NOS 12AX7 Amerex Bugle Boy long plate G getters. If I was buying new right now I still would buy the tube DAC 11 which sells for around $1200.00 less then the tube DAC 11 SE and go out and buy some great NOS tubes, cost would be around three to four hundred dollars, save alot of money and still have a DAC that out performs the more expensive model. This DAC's sonic performance is greatly effected by what tubes you use. So for my money I want to pick what NOS tubes that give me what sonics I'm looking for. So, in my opinion the change in a few parts or their working tolerances did not make any significant sonic inprovement, but without casting aspersions towards either AA or the US importer the DAC SE I experienced did not come supplied with NOS tubes, I guess the JJ's are better then the EH stock tubes in the DAC 11 but they both are crappy sounding, and you are supposely spending some of the extra cost on NOS tubes provided by AA. Can't answer your question regarding the top cover, the units I have seen all have the craved out tube design.
Thanks a lot Teajay. I read your full review, and also other comments from AA Drive 1 MK2 & Dac 1 MK4 & tube DAC II.

BTW, I am using AA Drive 1 MK1 + DAC 1 MK2 for abt 6 yrs. Now, I am hesitating if I should go for one of the following:
1. AA Drive 1 MK2 + DAC 1 MK4 / Tube DAC II
2. Audiomeca flagship transport + DAC
3. Luxman D08

It seems that the digital trend is towards 1-box player, with separated power supply. Do u think it's wise to get cdt + dac if upgrade?? Heard that the advantage of 1-box player is "totally solving the jitter problem".

Below is my little system for your ref.:

Speaker: Eventus Phobos
Pre: Luxman C800-f
Pow: Luxman M800-A
Rack: Finite Element Signature

Each gear is connected to wall socket directly with dedicated in-wall cable (individual fuse).

Moreover, I am a Redbook CD collectors, and I got over 2000 collections (actually I have no time to listen to them so start to sell some in order to get some money back, haa..).
Cykeric, since I own in my collection over 6000 redbook CD's, that's the only format I care about. In my opinion your statement that CDP's have a sonic advantage regarding getting rid of jitter, hence sounding better has not been my experience. I have listened to three of the highest regarded players and found them to be good but not as good as the AA reference Tube Hybrid in my system. So, I would recommend you keep your AA transport and upgrade to the Tube reference, with the right NOS tubes, this would offer you a much higher level of musicality in your system.
But some of well-known European brands such as Symphonic Line, Soulution, Densen, release their expensive new ref cd player. It's 1-box player with separated power supply.

BTW, since I am living in Hong Kong, not in USA, I would like to know every advice: is it safe to buy expensive gears (yes, AA Drive1 MK2 + Tube DAC Ref. is huge amt to me) at Audiogon??
Hi, Teajay,

I just got AA Drive1 MK2 + DAC1 MK4 yesterday. My initial feeling is the sound is warmer than before. However, it's not so transparent as before. The soundstage focus is also a little bit bigger!

Do you got the same experience when you use Drive1 MK2 + DAC1 MK4?? Or it needs some time for my combo to run-in / warm-up first?

Thanks.
Eric
Eric, have fun with your new pieces! Yes, give them at least 60 to 100 hours to burn in. As far as your concern over transparency, it should clear up with break in. I found the Dac1 MK4 to offer great performance, so give it a chance to settle in and let us know what you think.
OK. Thanks a lot.

BTW, do you have experience on Vovox products (textura interconnect, power strip)??
Guys, I just found another gorgeous sounding 12AX7 tube for the AA Tube Hybrid DAC, 1953 longplate Siemens.

This tube offers a touch more air/extension on the top, a slightly faster bass, an overall sense of more dynamics/details, yet is still retains the warmth/musicality in the midrange like the Amperex Longplate G-getters. Both are wonderful in this DAC, yet just a touch different.
Just wanted to share that another USA reviewer, Micheal Wright, this month did a review on the AA Tube DAC and gave it a superlative total "thumbs up" for its sonic performance.

Mike used to be a staff reviewer for the website, Stereo Times, he now is a reviewer for the Website, Ultraaudio. I have always enjoyed his reviews and believe he is an excellent writer with very good ears' regarding what a piece of gear really has to offer. For details regarding his take on the AA Tube DAC take a look his review. The only aspect I was concerned with he auditioned it with JJ/Telsa 12AX7 tubes, yet he still thought it's a killer DAC. However based on my experience the performance goes to a much higher level with the right NOS tubes compared with the stock tubes even in the SE version of the DAC.