Scott Nixon's TubeDac+

arthur · « **on:** 18 Mar 2003, 10:38 am »

I needed a tube touch to tame the edginess of digital music played through all solid state gear and revealing speakers. Since Scott Nixon's TubeDac has received such great reviews I ended up giving him a call. Scott is truly a great guy to deal with. He recommended that I go with the TubeDac+ which among other improvements upon the standard TubeDac also has some BlackGates in order to reinforce the detail, impact, and control.

The sound is very smooth and liquid but not quite as warm as I expected after having read some reviews of the standard TubeDac. I cannot detect any loss of detail – if anything it sounds almost edgy but that’s because I’m still burning in my Zu OxyFuel’s. If it was due to the DAC itself then it would have been overly analytic which this DAC is not. As with most top shelf tube gear, this DAC does an excellent job in reproducing the three-dimensional presence of all instruments, voices and even the background noises.
But enough of this slow discent into audiophile jargon - so far I’m VERY satisfied with the TubeDac+. For $450 I don’t think that I could have found nything that would sound nearly as good. An excellent bargain!!!

Weaknesses: I wish that it had space for an extra input (ideally I would want two coaxial and one optical input). Also, it would be nice if the voltage output was a bit higher - at 1V it is barely enough for my passive Creek OBH12 pre-amp, the Odyssey Stratos amp and the Legacy Classics - i would need more voltage if I was to use a bit less sensitive gear. Lastly, I wonder if the sound would change any if the DAC was in a heavy metal case? This might be the case since tubes tend to be sensitive to vibrations… but then again at this price I think that this unit is the ultimate bargain.

I wonder how the considerably more expensive mensaDIO would hold up against the TubeDAC+ in an otherwise all solid state system?

Well, either way I recommed this dac without any hesitation... sorry for sounding so rushed but I got some great music to attend to

MaxCast · « **Reply #1 on:** 18 Mar 2003, 11:44 am »

Welcome to AC arthur.
Thanks for the review. I'm glad to hear it is not too "tubey." Did you notice any problems with the phase issues? I'm sure many of us would like to pop this dac into our systems and check it out. Hey, maybe Scott could send out a loner?

Does anyone know how a 1v output vs. a 2v output translates to output levels on a given system?

rob · « **Reply #2 on:** 18 Mar 2003, 12:05 pm »

hi
i find the 1v out just about right and the imput sen on my amp is 500mv. it should be possible to change the output voltage by replacing the ref'resistor but if you do that you will need to change a few other values.i have thought about it but decided ' it works dont fix it'.
Arthur did you buy yours pre-made or diy?and what valves are you using?
also what dac/player where you using?
i have the std diy jobbie and love it and am looking at a'the tube+'
rob

audiojerry · « **Reply #3 on:** 18 Mar 2003, 03:32 pm »

Welcome Arthur, where are you located?
There are obviously many factors that affect apparent 'brightness' in a system. I'm very familiar with the Stratos and the Oxyfuel. While the Oxyfuel is a good entry level cable, it might not be a good match with the Stratos in that this combo would tip the balance towards greater brightness.

What are you using for a transport? The 1v output from your Dac combined with a passive pre may result in lack of bass and midrange fullness, which could also contribute to a brighter sound.

The Scott Nixon dac may be a great unit, but it may not be appropriate with your other components because of the low gain and it's revealing nature, from what I've read.

Off hand, I'd be willing to bet that a all in one cd player like the norH or Classe cdp .5, which I own would provide more gain to your passive and add smoothness and bass as well. The Classe is a great unit, built like a tank, and originally sold for $1995 when it was released in '97/98. It has a 20 bit Ultra Analog dac, digital outputs which I use with my dac, and can be gotten for around $600 on audiogon, which I think is a great bargain. The tubed NorH is also a very smooth, yet detailed, musical cdp.

Power cords and speaker cable also play a role.

Just some thoughts; not trying to be pushy. If I were being pushy, I'd tell you to get a good tube amp

arthur · « **Reply #4 on:** 18 Mar 2003, 08:07 pm »

Tank you, it's good to share with people who don't think that audiophilia is a form of neurosis

i'll try to answer all of the questions

i'm located in Los Angeles

as a transport i'm using a Pioneer DV-533 which is probably the weakest link in my system and potentially a major source of jitter, but it's hard to tell since my wires and DAC are still burning in.

the transport is connected to the DAC via a new Bolder digital cable (which supposedly does not need to be burned in). I had used the OxyFuels to connect the DAC to the passive Creek OBH12 but since it sounded bright and grainy I temporarily replaced them with my old MIT Terminator 2 s (the OxyFuels are currently cooking on a receiver).
The pre is connected to the Odyssey Stratos (powered through a TMC AC cable) using Bolder Type 1 IC’s
The amp is connected to the Legacy Classics via The-Music-Cable speaker cables to the highs and Naim Audo cables to the lows.
The Legacy’s are sitting on a trio of massive cones with triple cone tipped bases. I have always found the rear firing tweeter to be too metallic sounding and incapable of handling much power, but I seem to have taken care of much of these weaknesses by hanging 2 layers of grille cloth in front of them which muffles some of the brightness and distortion. These drivers are there for mere ambiance anyway so it does not sound like my modification has had any degradation on the sound.

When I switched the OxyFuels with the Terminator 2’s the sound became a bit more veiled and lost some of its three-dimensionality but also were gone much of the graininess and harshness of the highs.

The bass and mids sound very solid and present. I am very sensitive to this since my entry into audiophilia was through car audio where bass is king. Also, along with chamber music, jazz, world music, etc., I also listen to Death and Black Metal, where the subs get assaulted with machine gun like double bass rolls. This is why I decided to stay away from tube amps. Any tube amp under $10,000 that I’ve heard trying to recreate such music has made it sound muddy… or muddier, since the recordings themselves tend to be of very poor quality.

The 1V issue is also not that big of a problem for me since when I crank the pre all the way up the music is generally at near ear damaging levels. On many recordings I do not even dare to turn past the 4 o’clock mark. So far the DAC has exceeded my expectations.

But yeah, among other things, I wouldn’t mind hearing how a decent tube pre would change my sound.

audiojerry · « **Reply #5 on:** 18 Mar 2003, 08:18 pm »

Chamber, black metal and death! ... and Jazz!
Woa, a man with many tastes.

Nathan, I think we found a match for you

Quick, before Nathan can respond, what do you think of Dianna Krall?

nathanm · « **Reply #6 on:** 18 Mar 2003, 08:58 pm »

Before Nathan can WHAT? Muwhahaha!

Quote

I also listen to Death and Black Metal, where the subs get assaulted with machine gun like double bass rolls.

He's right you know. Er, unless said album was done at Morrisound.

And although I could start a whole other thread about the pros and cons of metal recording techniques, that kind of music is like a triathalon for your stereo. Far more challenging than EZ listening stuff.

byteme · « **Reply #7 on:** 18 Mar 2003, 09:40 pm »

Arthur,

How did you get hold of Scott? I've been trying to contact him for a couple weeks about the tubedac/tubedac+. I had some questions for him and also would like to order one of these two units. Glad to hear you like it. I've currently got a CIA VDA-1 but am chasing that elusive "you are there" two channel sound. I was/am torn between the Mensa DIO and the Tube Dac (+) but am leaning towards Scott's DAC.

For reference it will be paired with McCormack SST-1 transport, Virtual Dynamics Audition Digital cable, Warmouth IC's, Sonic Frontiers SFL-1 preamp, Newcastle 9080 amp and heavily tweaked Polk RTA11tl's via Zu Wax.

Anyone see any issues with phase or output compatibility with the Tubedac and SFL-1?

Thanks, Brian.

arthur · « **Reply #8 on:** 18 Mar 2003, 10:51 pm »

it was easy for me to contact Scott dackit@triad.rr.com - he responded to my email the same day with his phone # after which point i called and got him on the phone every time before making the purchase.... i even called a couple of times after putting in the order and he answered the phone every time. He is a very pleasant guy to deal with... he is very knowledgeable and like a true Southerner he'll never rush you or make you feel like your questions are simplistic.

regarding the phase, i just connected the negative speaker wire to the positive speaker post and the positive wire to the negative post which takes care of it... but according to Scott you don't even need to do that since generally phase is set randomly on most recordings - it just shifts the spatial cues.

oh and regarding assembly, the TubeDac+ is only offered pre-assembled.

at this point i can definitely say that the sound of the dac is only getting better with time (i've only had it for 3 days)... but yeah i'd be interested to hear what you people have to say about my wires. the ribbons on the Legacies are a bit tricky to control so i wouldn't mind experimenting with some wires after everything burns in and maybe after i try a nice tube preamp to really hear what the Creek OBH12 does to the sound.

ABEX · « **Reply #9 on:** 19 Mar 2003, 12:15 am »

I had thought that there was a shootout using all the newer DAC's mentioned?Although it might be a good idea to do another shootout having the following DAC's:
Camelot's
MENSA DAC-w\Nathans favorite Tube-O-Lator tweek!

Scott NixonsTubeDac+
CI DAC
MSB DAC
And any other Dac that is under $1K plus an Ultra Expensive DAC

Seems like there are new mods being added to these DAC's that it's really hard to keep up with what has what.

AS far as using a Passive which I also use I did not think you would have to change any values but the values used in the output resistors.When I sent my DAC to Bolder I made it a point not to change the 7v valued outputput resistors.It made it so I cannot go beyond the 12 o'clock position on the Vol. controller or else I might damage my drivers.

My amp has an Impedance rating of of 22Kohms and sensitivity of 1.4v I think.My speaker's are rated to be driven with an amp that has 50-300w.
In my case it would have been better to have set the Output resistor values to between 4-6v I think instead of 7v.That might give you an idea of where to set yours if you have Scott rework the unit for gain.
Now I must get back to training to bomb Iraq on my computer!

Hantra · « **Reply #10 on:** 19 Mar 2003, 01:40 am »

Guys:

I have to tell you this.

I went down to a friend's place who is a dealer, and I took my SN Tube DAC. I just thought it might be fun to see how it stacked up against the big daddy DAC's he had.

Here's where I am going to lose half the audience reading this post b/c they aren't going to believe this is true.

We first listened to the Audio Note DAC 3.1x balanced. The system was an AN CD 2.1 used as a transport, a Consonance ref. preamp, and some Philly Audio Neutron 300B monos hooked to the Cain & Cain Abby. Audio Tekne power conditioning was used along with all Audio Magic cabling.

This wasn't a technical shootout as much as a fun listen, but we did use an SPL meter to set the volume. My friend was trying to decide whether to keep the AN DAC, or the Zanden for his personal system, and wanted my input.

So, listening to the AN 3.1x balanced was an amazing experience with this system. I really like the Abby's, and these 300B's are the quietest, and have the best bass I have heard from SET's. The 3.1x balanced was amazingly good with a wonderful presentation. Very deep, and very huge soundstage with great detail, and none of the digital noise I have heard with other DAC's that oversample.

We fired up the Zanden, and let it warm up for a while. We listened to the same tracks (Pizza Tapes, Bill Frizell's Blues Dream), and I liked the Zanden okay. I have to say that the Zanden had more sparkle up top, and perhaps the highs were more well defined, but that's all it had over the AN. The problem I had with the Zanden is that I heard the AN first. Had I not heard the AN, I would have said the Zanden is amazing!

The AN had something the Zanden didn't. The AN sounded like music. The Zanden had no flow. It didn't flow like real music. I saw Phish the week before, and I like seeing them because their music flows through the set, rather than being a collection of individual songs. The Zanden was more a collection of amazingly rendered musical events. The AN sounded like music. It would pick me up, and take me away on the Blues Dream disc. Amazing. Zanden didn't do it, although I did hear more on the top.

This whole time, the SN Tube DAC was warming up, and I decided to go put it in, and do some listening.

We put in the SN DAC, and played the same tracks. The SN wasn't quite as tight on the bass, but I understand that has been improved in the newer version. The SN didn't have quite the depth, or width of the AN's soundstage, but it didn't lack much. I'd say maybe a foot or two depth-wise, and a foot on each side of width. That doesn't mean much to you unless you know the room size.

The room was 20 feet wide, and about 15 feet long. We had the Abby's facing the long wall, and about 4-5 feet into the room. So, this little bit of depth was not THAT noticeable, and certainly not worth $6000!!!!!!! Well, I guess actually $5650 more than the SN DAC.

I must say that I was flabbergasted, as was my dealer friend! We noticed the flow was back on the SN, and things sounded like music again.

Tha Zanden got sold the next day. AN is still hanging around his place, but only b/c he is an AN dealer.

Jay S · « **Reply #11 on:** 19 Mar 2003, 02:06 am »

Hantra,

This is great. I had been reading about AN dacs to get a sense of what "ultimate" performance may be. Its good to know that the SN and the Mensa provide most of the performance for a small fraction of the price!

Its great that Scott has this excellent product to offer. I almost wish I needed a dac for another system so I would have a valid excuse to get one....

Your point on AN vs SN shows why its important that we not get too focused on getting that last bit of performance from a particular part of our audio system, and focus instead on the areas we haven't much attention to. In my case, I don't have a power filter in my main system so that is priority #1. Priority #2 is supplementing my Echobuster panels with acoustic foam in the seam of my wall and ceiling. Priority #3 is playing around with my speaker positioning. Yes, it should be #1 as it is free but moving heavy speakers and heavy stands with spikes is not my idea of fun. Digital? What me worry?

Hantra · « **Reply #12 on:** 19 Mar 2003, 02:13 am »

Jay:

Since you mention power, I will say something else I learned from this listening experience. . .

The Audio Tekne really hooked up the sound a LOT vs. NOT having the DAC plugged in there. It did much much more than changing to a nice power supply on the DAC. I didn't notice enough difference when I used the nice power supply vs. the standard Chinese issue wart.

I am on schedule to try the DeZorel next, so maybe that will help also. .

B

audiojerry · « **Reply #13 on:** 19 Mar 2003, 02:14 am »

Hantra,
do you suppose you could persuade your dealer friend to post his impressions on this forum? It would be a great way to help address the doubters.

Hantra · « **Reply #14 on:** 19 Mar 2003, 02:20 am »

Dude, he is an Audio Note dealer. . hehe I kinda doubt it. . .

B

Jay S · « **Reply #15 on:** 19 Mar 2003, 02:29 am »

The DZ noticebly helped when I plugged my Cary and Mensa into it. Enjoy your home audition of the DZ!

doug s. · « **Reply #16 on:** 19 Mar 2003, 03:34 am »

jay,

pick up a couple of cheap isolation transformes on ebay - one for the dac, another for the transport. these things really make a worthwhile improvement, & they can be had for pennies on the dollar. i paid ~$50 for one that retails for ~$400, another i got for ~$30 that retails for $600, & i paid ~$50 for a combo variac/isolation transformer that goes for ~$300. (oh yeah, i also paid $125 for a mondo hewlwtt-packard 0v-20v/0a-4a power-supply that retails for ~$1k - i use it for my turntable's origin-live dc motor kit!

)

you really wanna keep the digital items isolated from the rest of the system, so get another isolation transformer for preamp & other sources, if ya want to condition all yer equipment. a huge one would be needed for amp so as not to impede its dynamics, but even then, ya can find the big ones for $100-$200 - a lot cheaper than buying fancy name-brand audio stuff for amps. i got a used vans evers unlimiter for my amps that doesn't constrict the sound - it was a good deal at $325, but if i'd known about the isolation transformer thing 1st, i'd have gone that route instead.

doug s.

byteme · « **Reply #17 on:** 19 Mar 2003, 05:10 am »

Quote from: arthur

it was easy for me to contact Scott dackit@triad.rr.com - he responded to my email the same day with his phone # after which point i called and got him on the phone every time before making the purchase....

Could you please give me the number? I'd love to get hold of one of these!!

Brian.

arthur · « **Reply #18 on:** 19 Mar 2003, 08:55 am »

hope that scott won't mind me posting his phone # .... but then again it's more business for him so i don't see why he would mind:
336-884-7394 ... but please only call him with serious inquiries since I’m not sure if he wanted his # publicized.

oh, and about the power supply, i was concerned about it myself but he told me that swapping it for a more expensive one won't make much difference since the one that he provides is already tweaked.

Given my system (as posted above), what reasonably priced IC’s would you recommend instead of the OxyFuels and the Type 1’s ?

Hantra · « **Reply #19 on:** 19 Mar 2003, 01:07 pm »

Quote

Given my system (as posted above), what reasonably priced IC’s would you recommend instead of the OxyFuels and the Type 1’s ?

Arthur:

Since you said you need to warm it up, try out some Kimber Hero. Even warmer? VanDenHul, or PAD. If you go with those, look at used ones so you won't lose money on them.

HTH,

B