What is the deal with the ART DIO

I have read some unbelievable raviews on this dac.
Any comments on it's performance?
Properly modified, it will amaze you. I found out about Kevin Morris, who modifies them, from an un-named audio magazine reviewer. I hope to have mine back soon from him.

Since mine was modified earlier by another shop, I recieved a lower price rate than a stock out of the box unit. I'm not sure what the price is for the complete set, though I know that he does perfect work and is very reasonable. His phone number is (515) 288-8464.

The Di/O can be had for $122 plus shipping from www.fullcompass.com. I am new to digital, so I wouldn't be the guy to ask whether it is better than Brand X DAC's. I can say that I was impressed hearing the Di/O that Kevin had modified, though.
Here's my one post for the day : )

There are at least three different Integrated Circuit's ( IC's ) that various modifiers use. As such, the results from unit to unit might vary quite a bit depending on what chip was used. Obviously, some modifiers will do some things differently than others and use different parts doing them. This is strictly my take on the unit that i listened to. A friend of mine was kind enough to let me borrow his to audition so that we could compare notes on it. This specific unit had been modified by Bolder Cables and was being run off of a much larger than factory stock power supply. This was their latest version as they have changed which IC they are using when modifying the DIO's. As such, it is supposed to offer the best tonal balance of all of the various IC's according to what i've read. I know that one of the two other chips being used result in a slightly muddy / murky presentation while the other one is brighter and leans towards sibilance. This specific chip is supposed to be somewhere in the middle.

Having said all of that, i found the unit to sound just slightly forward in the upper mids / lower treble. This can tend to sound slightly "clearer" due to the ability to pick out vocals a little better. After all, this is the range that most of the harmonic overtones take place during normal speech or singing. However, it did this without sounding sibilant or completely in your face. As such, some may really find this "feature" quite appealing.

Other than that, tonal balance was pretty good. I did not find it to be drastically leaning towards brightness nor warmth. There were no rough edges and as such, sounded pretty smooth and even. For a "cheap" digital device, i think that it did pretty well in these regards. However, i was somewhat put off in a way that left me feeling that something just wasn't "right". Kind of like the music had been "sterilized" and was lacking "emotion". Some might call this having a lack of "PRAT" while others will simply refer to it as a lack of "musicality" or "drawing power".

My big problem with what this unit does to the signal is what it doesn't do. That is, i found that inserting the modified DIO into the signal path caused my soundstage and imaging to collapse. I was left with a presentation that lacked height, depth and width. Center fill was not nearly as strong and i had a very definite left / right speaker presentation taking place. In plain English, the DIO lacks "dimensionality". Whereas i was used to hearing a 3D presentation, i was now listening to a cardboard thin replica. This was something that i found annoying as i am very much "into" spacial characteristics and being "engulfed" in the music ( when the recording allows ). Once again, i was not drawn into the music although i did not think that it sounded bad.

Another thing that i noticed about the DIO was that, while transient response seemed good on the initial attack of the notes, it lacked the proper decay characteristics that one hears on better gear i.e. the striking of a bell rang and then quickly faded away. Going to another DAC ( SS or tube ) gave the bell a more gradual decay time which in turn sounded far more natural. Bells just don't "ring" and then fade off instantly. In this respect, i found the harmonic structure to be lacking i.e. "dry". Once again, it was not bad, it just wasn't what i knew a really good system was capable of achieving.

As such, i can see why some people think that the DIO is great. It does get rid of much of the digital glare that many lesser designed players / DAC's suffer from while presenting a smoother overall presentation. However, it is quite lacking the "sound field" and harmonic textures that many better players / DAC's offer when properly set-up. As such, one might not notice this unless they had previous exposure to a system / DAC that was capable of sustaining a 3D image with excellent harmonic structure and proper timbre.

For many, it may be a step in the right direction, but it is not a BIG step in my opinion. Obviously, others have had different experiences and will therefore have different opinions. When you total up the money spent on the unit, having it modified, going to a larger power supply, it ends up putting it into a slightly higher price category than if you were to use the unit as it comes factory stock. While it can still compete in that range, i can think of other USED DAC's that i personally find more suitable to my tastes. Since we are comparing a brand new product to a more expensive but USED item, i would still consider a modified DIO to be a relatively decent investment. However, it is surely not the "giant killer" that many have made it out to be ( in my opinion ). Sean
Basically, the deal is that, when properly modified, DI/O can sound very good, beating out digital equipments several times its meagre price. I have one that I modified, and my experience comfirms what I've said above.
I just bought mine and am waiting for a Digital Cable to arive!I will be mating it with a Phillips CD-80 1989 Vintage Transport!If you have an old machine and do not want to speand for a new machine or more expensive DAC then I cannot see anything wrong with trying it!

In my mind it's the poormans DAC and that's fine for me!I'm always looking for a good value!You are not going to get a SOTA DAC for $130 ,but I bet you will get improvement and with a few tweeks you'll get better sonics!

I wonder how many synergy issues are involved with getting the most from the unit also!Like trying out a few different cables or Changing out the OP amp Caps and resistors!

Paul Lam of FT Audio gave praise for it when mating with Phillips CDPs also!So it is well worth the risk to get one if needed IMHO!

Good LucK!
I just had to send my Tact 2.2X back to the factory for repair. I was using the internal 24/192 DAC. When used with the internal room correction system and volume control, I don't think there is a better DAC out there. So I dug my ART DI/O out of storage to use in the interim. It is not modified. It is very good for the money, but not in the same league as the Tact. I agree with Sean's comments about soundstaging. That was the first thing I noticed. This DAC has much less 3D imaging that the Tact. Can I live with the sound until I get my Tact back? Hell yes! This thing is very good for the money. I'm going to send it in for the mods just for kicks.
Somewhat contrary to the comments above, I think soundstage is one of the strength of my modified DI/O. It is very wide, but about medium depth and height. Within that field, imaging is finely layered and accuratly presented, IMHO. However, as sean said, there's many varieties of DI/O recipe out there, and I believe my DI/O is unique in the regard that no other DI/O is modified in the exact same way as mine. I just wanted to make a note that soundstage could be improved with modification....though I'm not sure which of my two dozen mods helps soundstage.

Glreno: so you moved from Hermes to Tact 2.2X? Good move...I wish I could do the same. :)
Just curious Sean -- did you take any steps to optimize the sound of the DIO -- such as trying different digital cables or experimenting with chassis resonance issues on the DIO and its power supply? Or did you just pop it in a system that was already optimized for a different DAC?

I don't know if I have the latest chip set in my Bolder modified unit, but it does provide a very wide and layered soundstage... My unit has great dynamic capability and excellent articulation at low bass frequencies. The highs are as pleasant, natural, and extended as you will find in any DAC I have heard.

Before you buy a very expensive DAC I'd want to investigate the DIO a bit further.
Just bought an ART DI/O here on Audiogon for a headphone system. It's headphone nirvana! I'm using it with a CAL Delta transport, an ASL MG OTL tube headphone amp, and a pair of Senn HD545s (which I like better in this setup than the HD600).

The other responses motivated me to give the ART a try in my speaker system (modded CAL Delta, Tact RCS 2.0, AES AE-3, AES SE-1, Merlin VSM-M, and Janis W3 sub). I was able to A/B the Tact DAC with the Tact/ART DAC by switching between inputs on the AE-3 preamp. I listened to solo classical guitar, solo cell, and solo piano. In all three cases the Tact was more three dimensional, harmonic structure of notes was more perceptable, the sound of fingernails on nylon strings was more obvious, the percussive quality of a hammer on piano strings seemed more accurate, and the sound of the bow moving across cello strings was more immediate. The ART was very round sounding both with a warmer tonal quality and with a slower attack on notes (less PRAT). I was surprised, however, by the fact that I seemed to have a more difficult time leaving the ART than I did leaving the Tact when doing comparisons (I guess you might call the ART seductive).

The bottom line is that the Tact is the right DAC for the speaker system, but when I want to have a truely mellow warm headphone experience, the ART DI/O is just the ticket.
Quick follow-up: I should have mentioned that my ART DI/O is not a Bolder Cable mod but rather was done on the West Coast somewhere and I was using an inexpensive Atari power supply. (Using a Bolder Cable powersupply with a Bybee filter might be interesting.)
I think the problem with the DIO question is that none of us are comparing apples to apples. We have some folks with stock units and others with DIOs in varying stages of modification. Of those that are modified (mine included) probably no two have exactly the same mods or ancillary equipment. For example, I have one of the Bolder mods, a Harmonic Technology digital cable, Parasound CDB-2000 transport, Monolithic P3 power supply, and a Perpetual Technology P1 upsampler. With all this other gear, I can assure you that the sound of the modified DIO is quite good if not state-of-the-art. Possibly the new TacT 2.2X is a bit better, but it costs between 4 and 6 thousand dollars (depending on options).

That said, I wouldn't hesitate to put my setup head to head with a TacT 2.2X or the lower priced TacT RCS 2.0, or any other highly regarded DAC...
Can't confirm these glowing reviews. A friend had his DIO heavily modified by Bolder Cables complete with outboard power supply and it has some idiosyncracies. He had previously borrowed my Hermes and stated the Kora beat it hands down but that it sounded very good for the money.
Really, Celtic66, the Hermes beat the DIO hands down -- that's interesting. I'd like to hear one do that in my system and if it truly beats the DIO, heck, I'd buy one.
Anyone have a Hermes in the central NJ area that would like to do a shoot out? E-mail me and we'll set it up...
What IC's are being used now? I know that people are using the Linear Technologies LM 1365 and LM 1362, what is the other IC?
I have read that some IC's do not work good with the unit.Boulder uses Belden,I am getting Canare to see if it will work with it for a low cost cable until I find something better!
Someone wrote me with this Q?
Will the DIO work with any player with COAX out?My response was--yes!
I've read about and experienced clock locking problems with some digital cables. This causes a momentary dropout. I'm using a Cardas Lightening that works fine.
I do not know what Bit DAC's you might be using ,but upon inserting the DAC with the new Canare Cable into the loop I was able to discern that some of the underlying Details that I was missing were more apparent!The effect is not astronomical,but it is there!

The most important improvement that I noticed was a better presence of Cymbals and Voice info is more distinct.

I will also point out that this is inserted in to a system which only had a 16bit stock Phillips DAC!Anything just about short of getting a Custom Powercord would probably be an improvement.

Another fact I will mention is I only had time to play 4 tunes that were fresh in my mind from listening at high Vol. yesterday as a good reference .The amp was cold and the CDP \ART DAC were on for 10mins so that they could warm up.The sound is rather sterile until my system has a chance to get warm so these are just initial impressions.The DAC and the Cable will also need time to burn-in for the sound to warm up.

The DAC Mod.\Tweeks would probably help also.If it was voted as being used in the playback at CES for Finest Sound Booth at the show there must be merit in using it .For me it was worth it!

I guess I should have specified; "Which op-amps are being used besides the Linear Technologies 1365 and 1362 chips? Kevin Morris uses a special Motorola chip which betters them both. Just wondering?
I own a stock DI/O. Definitely a great deal. Even in stock form it improves the sound of sub-$600 CDPs. I agree with Sean about soundstage. Also, the bass is rather boomy in my experience.

Having replaced the DI/O in my main system, I moved it to my second system (headphones). In that system, it has an effect similar to the Stax diffuser or Headroom processer--sounds less like headphones--may relate to soundstage issues noted above. That is a nice effect because it doesn't degrade the sound or change the frequencies as the those processor technologies can.

I haven't heard a modified DI/O, but relatively inexpensive used DACs at current prices here on Audiogon beat the stock DI/O in frequency balance, texture, and soundstage. I have retired mine again in favor of a Muse Model 2 for the headphone system. So, while I consider the DI/O a great deal and hope to use the A/D feature in recording at some point, there are a lot of other great DAC deals out there worth considering as well. Perhaps a trip to Plato's to hear the modified version would make me a convert. . . .
The conditions that i listened to the Dio in placed it in just as much of a "mess" as the other DAC's being auditioned. That is, they all used the same cables, lack of optimization of the system, no isolation, coupling or damping, etc... We ran them the way that they came each sitting on a shelf. Within the confines of the same system and a matter of moments to switch input / output cables and discs, the DAC's were all given the same opportunity to "strut their stuff".

As Jbweaver mentioned, my brother felt that the ART was slightly "loose" on low frequencies. Personally, i did not think it bloated by any means although this was one of the very first comments that my brother passed onto me. As such, he obviously found it very noticeable. My initial observations were regarding the soundstage and harmonic structure, so we might have been listening for different things. I know that once i take notice of something, that particular aspect tends to dominate my perspective like a sore thumb draws attention to itself. Sean
It's tough to say which mod will work in which system. Also, mods seem to be system dependant, as cables are. This said, personal experience reported here is irrevalent, unless system parameters, hearing ability, and room acoustis/treatments are consistant.

I've found the modified Di/O to better my DAC costing twenty times the cost of the DAC which it replaced. Muddy bottom end? Loss in spatial info and soundstage anomolies? Not in my system.
I agree that cost means little when buying an audio product. MOST of the time, much of what you are paying for is Research & Development ( R&D ) and marketing, not the actual parts quality of the unit itself. As such, that is why some cheaper products actually blow the doors of off more expensive components. Not only are the cheaper ones typically using fewer parts, they just might be using better quality parts.

This is the very reason why and how Stan Warren, John Hillig, Richard Kern, Ric Shultz, Dan Wright, etc... can make improvements to just about any product out there, regardless of cost. They simply improve the parts quality of the design that is already there and the results are typically audibly better and quite noticeable.

As most of you that have read a few of my posts have seen me say before, buy what you like and what you think sounds good in your system. Don't worry about what some reviewer or anybody else thinks. Even if that "jerk" is me : ) You have to live with and enjoy your system, so trust your own ears. Nobody can tell you better than yourself what you like or don't like. Sean
A thing I am finding is that if you can find a respectable product and have it Modified you will do better than paying 10-20X as much for some things.
I have a B&K ST-202 that I will not sacrifice unless I need to drive a real difficult load.I think that Class A BIAS'd gear,quality parts,wiring,tweeking and design changes will improve the sound dramaticly!

The ART DIO should sound better than most stock DAC's after modifying!I think it's a safe bet to have a reputable Co. like BOulder do the Mods!Some Mods I think are more critical than others!I think the BIAS toward Class A,Parts and the wires are most important!

Those are my observations!
I would only add that i think that the physical layout of a circuit becomes FAR more critical with digital signals due to their "RF based" nature than it is with other standard line level analogue circuitry. With a chassis the size of the Dio and the limited amount of space that it offers, it would be next to impossible to keep RF from leaking back into the power supply and analogue circuitry. The fact that they were able to actually squeeze a tube in there AND have both a DAC and ADC in it simply amazes me. Sean
One Tweek that can be done immediately is getting rid of the 9V PSU unit.I had a Variable Ratshack unit I used in it's place.

I do think that having the Op Amp and it BIAS'd to Class A operation would be a big step in the right direction!There seems to be a touch of veiling to the unit that might be resolved by switching out some of the stock components!