[AdamZuf]

i was looking for the best budget source (i also care for transportability, but it ain't the issue).. and went with the ART DI/O DAC. so, until now i end with a $97 DAC + about $60 including PSU with great sound.. much better then my Echo Darla SC (which is considere very good, at least on unbiased measurements). the only thing i ever soldere was speaker cable tips a few years ago, and of coarse i don't know crap of electronics. but i decided that i'll do it myself, for my first DIY experience and because money is still an issue. i was adviced by a great ART modder, named Claude G (he is mentioned in the second FAQ below, and there are a few links to his findings). he is still helping me in the capacitors issue, which he has a very original way to install, he adds 0,47mF/100V in parallel to the original caps under the board (very small caps)..better results then replacing the originals with whatever you can fit there, and easyier for electro-noobs! (like making a mirror cap!)

FAQ's:
http://home.ca.inter.net/~cfraser/DIOFAQ.htm
http://www.angelfire.com/ca/rchau/audio.html#DI/O

here are the modds i did, in order:
1. 9VAC, 3A PS (from start, custom made in israel, here the ART kinda matchs my Darla SC)
2.remove the tube (can't say what improved exactly here too, i did it fast since the unit got so damn hot with it, i was afraid to keep on going with the tube..so i didn't have the time to really know the ART before it..but somethnig seemed better)
3.75ohm resistor installed in an RCA plug in the digital output..no difference to my ears, but i have to check out now,after i made the following mods).
4.remove DAC and ADC chips, install sockets instead, and try LT1365/LT1362 opamps on the DAC socket - i like the the LT1362 more, though i thought i'll like the 1365 more because it's supposed to be darker - instead i found it to suck on life from mid-bass dynamics and leave more lower fequencies there, hollowing.. the 1362 gives full & balanced frequency response to my ears.. this is one major upgrade! (and most difficult, but not really, anyone can do it if he's careful!) - this one gives the ART another class- improvement everywhere!
5.replace diodes - very nice upgrade, added a refined flavour to the previous one, but i can't put my finger exactly on it, sinse i continued to the next right away (exited from soldering the first time, sorry it wasn't the best thing to do for others to learn m,ore about the mods)
6.remove main output caps - this is an interesting one, as it reveals the true nature of the unit and the other modds- which are previous to it in the chain, so it is not recommended without other improvements first. in the point i did it - it was the mod of tranceperancy! some of treble refinement lost - but only in the recordings where it's supposed to be lost. interesting flow in the dynamic structure through the whole spectrum, and a bit brighter overall - i'll try to restore the caps soon just for fun.
there are two other hidden caps to remove, which i didn't remove it - i wonder how the unit behaves when one pair is removed, or the other, or both!
7.75Ohm 1/4W resistor in the digital INPUT - wow! this one is from today. great mod - and compliments that nature of structure flow from the output caps removal. i'll try to describe better later.
resolution feels better, and there's something more interesting in the way sounds distribute into the depth. i can say thums up for clarity, but i'll have to check out some more recordings to say the same for character.great transition between left and right channels, i'm impressed with the treble ability the most.

at this stage i can still put an opamp on the ADC socket, restore the tube, and use the ADC part of the unit - flexibility is great!

i'll get on to the capacitor thing (it's hard to get something so thin that will get under the board). as far as i understand, the other easy and effective modds to make are grounding, and getting an isolation transformer for the unit (a major one). both very easy.
the ART has a very strong 7V output signal (unlike the ~2V standart, sinse it's made for musicians, not audiophiles), and my amps loves this. with some amps you will have to change it (the amp won't handle it and clip).. don't know how complicated it can be..but probably not too much

if i can do what i did , anyone can do it (i think..

)

anyway, i'm very impressed, and things are going to get better with burn in! (and caps adding... oooohhh i can't wait)
it is said that the ART can be a very good unit that competes with very costy DAC's, regardeless of its price..so don't underestimate it!
& i'll be glad to help anyone who will choose that route, as others helped me.

just wanted to share..good night fellows

BTW, claude sent me the most important DI/O discussions and conclusions in a .doc file, i sent it to a fellow headfier, and he'll host it - then i'll give you the link. very informative!

 

[zowie]

I've been shopping for one of these (probably a DPS which includes mic pre's) to use as a front end for recording to my NJB3. I had no idea they were being used for home audio and at this sort of following. This may be the best tip I've gotten off these boards yet.

 

[AdamZuf]

little addings:
my ART came with some silicone looking material that was melted on some parts of the electronics - probably so you won't touch it!
so just heat the tip of some sharp metal object you don't need clean afterwards - and take it off from where you need to mod! (for me, it was on capacitors and diodes).. it melts easy.
in my unit, there is some of that on the strip cable...great!
that way it can't break from taking the main board in and out.
also, there is some red glew on the screw that connects the main board to the case. if this is how you got your ART..so chances for being able to open the screw aren't really good, even if you melt that glew around it...i had to drill threw it (and carefull on the board!), so here goes that screwing..

 

[DeathDealer]

These look nice. Same op-amp as you describe.

SmArt DI/O

 

[AdamZuf]

yes, there are quite a few mods i didn't list - i'm trying to get some more info on the Yahoo DI/O group on what are the rest of the really effective and easy mods. i'll post the conclusions and where to get all of the parts, and their numbers.
when i'm finished, i'll post pictures of mods and instructions the best i can, so people like me won't have to go through all of the process i've been.

 

[zoboomofo]

Quote:

Originally posted by AdamZuf zoboomofo, to which caps, resistors (all of the analog path?) and output IC's brands have you changed? did you mod step by step, and gave time to some burn in/ psychological burn in? comments on sound for different mods? please post your reply in the thread i gave link to, 2 posts ago..look up. i would like the info to gather up. thanks

Hi Adam, sorry for the delay but here's my reply anyway. I used Craig Fraser's web page (one of your links) for my modding guide with the same cap brand and values. I modded all of the resistors noted, and all but about half of the smallest electrolytics replaced. I'm really looking for a proper set of digital ics - my system is outgrowing them

- they're AR Pros. About the digital noise, I noted that I could avoid the flutter using one cable over the other. The Acoustic Research toslink feed (to my Monarchy 48/96 to coax to DI/O) is noisy but the Acoustic Research coax is not. I can do direct comparisons thanks to a switch on the back of the Monarchy upsampler. All my mods were done at pretty much the same time, and they're a bit short of a smArt DI/O now that I recall. I'll probably make use of the rest of my parts on the DI/O this winter (that's when I do my diy'ing

).

 

[zoboomofo]

<here's my blurb about how the DI/O decided my upgrade path.>
<Skip to the last paragraph to see DI/O mod effects.>

Oh yeah about the sound. The stock DI/O (with AR Pro coax fed from Fostex COP-1 connected to the knee bone

from AR toslink from Sony carousel) had a large sound. It sounded cool at the time. The digital harshness and glare were pretty awful though (a bit worse than the already weak transport) . The addition of the DIP 24/96 (exit Fostex COP-1) dropped the noise floor and made the music more vibrant. Everything was magnified. It was great. I almost even liked hearing the harsh highs with this set up.

Unfortunately the grain was still awful, and there was still zero depth despite the DIP's texture and the DI/O's height. The DIP 24/96 was replaced by the upsampler 48/96, with a tradeoff in sound. The relative blackness I enjoyed with the DIP was gone

, but the treble harshness gave way to smoothness sort of. Instead of a treble that bites your head off then spits it on the floor to be kicked around, this new treble irritated only mildly. It sounds like the ugliness was pushed upwards away from the 10kHz level.

The mods that I did were based on recommendations on the web by Craig Fraser and The Bolder Cable company. I can sort of comment on the changes in sound at each stage even though my testing was brief in between them. The first thing I did was to jumper the I/O board where the electrolytics sit. This removed some of the wool from the sound

. I switched the analog resistors to improve on the stock carbons, and to attenuate the signal. Yup it was quieter than before. Next was the IC - the LT1362CN. This opamp changed the DI/Os character the most out of all the mods I did. The treble sweetened up a lot

but the sense of height diminished. There was suddenly an ability for subtleness to the sound too. In hindsight some of these opinions on the IC swap may have been influenced by the resistor swap. I forget what I did over the next few weeks, but they included new diodes, and reservoir caps (still some left to do). I remember the caps making a dramatic difference in the sound. The biggest was added refinement. The sound was less flabby and grungy. Unfortunately, this tighter sound was smaller than what I had before. That's all I can remember right now.

One more note: changing the transport to an Arcam Alpha 8SE cured the anemicly weak sound. Sweetness no longer came at the expense of warmth and body.

 

[AdamZuf]

1. Quote:

Originally posted by zoboomofo The first thing I did was to jumper the I/O board where the electrolytics sit. This removed some of the wool from the sound

can you tell more about the effect? "removing the wool" means brighter?
is the jumpering hard to do? (in which page is it... i lost it now)
Quote:

I switched the analog resistors to improve on the stock carbons, and to attenuate the signal. Yup it was quieter than before.

did you replace just the ones that Craig mentioned in his page?
to which type did you replace
Quote:

I forget what I did over the next few weeks, but they included new diodes, and reservoir caps (still some left to do). I remember the caps making a dramatic difference in the sound. The biggest was added refinement. The sound was less flabby and grungy. Unfortunately, this tighter sound was smaller than what I had before.

reservoir caps? what's that?
which type of caps did you choose?

i would appreciate if you mention where you got your parts!

 

[zoboomofo]

1.
Q
can you tell more about the effect? "removing the wool" means brighter?
is the jumpering hard to do? (in which page is it... i lost it now)

A
The removal of C17, 18 on the I/O board lowers the noise floor. It sounds wooly in comparison with these caps in place. By jumpering, you'd be desoldering these caps, and replacing them with wire. It was the easiest mod for me since it has the most accessible board space.

2
Q
did you replace just the ones that Craig mentioned in his page?
to which type did you replace

A
Sorry. I looked at Craig's page, and I don't see the alternate resistor values. In that case I can't remember where I got the values. I remember 2 possible sources of these values: Ray Chau's page (do a google on "diomods NAD" and his page of mods will come up). Another source was the diomods site itself. There's some discussion about using these resistor values as an analog filter or something - it might interest you. Once again I apologize for the lack of info. It was soooo long ago.

3
Q
reservoir caps? what's that?
which type of caps did you choose?

A
The reservoir caps would be the large patch of electrolytic capacitors if I recall properly. There's a table outlining the values, and brand on Craig's mod page (go from his diofaq to his mod page then to power supply caps). I used the Panasonics as prescribed.

Up here in Canada, the easiest source of parts is Digikey for the Panasonics, and the LT1382 opamp. I went to an Active Electronics shop to get the Dale resistors (they don't carry them anymore) and diodes. I've gone all over town for parts so I lose track of where exactly I got what for the rest. I'm real happy with the DI/O as it is now. I think I'll continue to build around it as I upgrade.