Anyone familiar with Art DI/O mods?
Oct 21, 2002 at 11:55 PM Thread Starter Post #1 of 14

fyleow

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Has anyone modded their Art DI/O? If so can you help me out?

Are there any websites with a list of tweaks that I can do? I tried doing a search and the best I could get was a Yahoo group. Unfortunately it's not really sorted and I had a hard time finding the information I need. Basically I want to know all the mods that might boost sound quality. Primarily interested in knowing how to reduce the gain. Also what ICs/caps can be replaced to improve sound.

I noticed that the outputs od the DI/O are 1/4 plugs. Replacing them with RCA doesn't seem too difficult but that probably won't fit the case. So what's the solution? Drill more holes?
 
Oct 22, 2002 at 1:45 AM Post #4 of 14
Quote:

Originally posted by fyleow
I noticed that the outputs od the DI/O are 1/4 plugs. Replacing them with RCA doesn't seem too difficult but that probably won't fit the case. So what's the solution? Drill more holes?


Cardas GRFA connectors will fit the case. These will also allow you to remove the circuit boards from the case without any desoldering.
 
Oct 22, 2002 at 1:59 AM Post #5 of 14
Make sure that the jacks have the fastening nut on the outside of the case, or you'll never be able to remove the board without unsoldering them.

kfaiman posted cfraser's site, which is the best one, IMO. Another DI/O site was created by Ray Chau at http://www.angelfire.com/ca/rchau/audio.html#6.3.1

www.audioasylum.com has a lot of information on the DI/O in the digital drive forum. Do a search and start reading...do this when you have plenty of time
wink.gif
 
Oct 22, 2002 at 9:52 PM Post #6 of 14
Thanks for all the sites guys, still one thing I am not really clear about though. Confused about changing the Gain to a desired level of 2V. How do I do that?

EDIT: On the stock Art DI/O what kind of connection does it use for the Digital SPDIF in? I can just change it to Cardas GRFA right? Where can I get the Jensen Transformers for the mod? Don't seem to be able to find them anywhere.

Thanks!
 
Oct 22, 2002 at 11:04 PM Post #7 of 14
How do you take the boards out of the DIO? Some of them seem to be anchored in pretty well:

Is it only the screw in the back near the RCA digital I/O that's holding the rear I/O board?

How does the main board come out? Do you have to pry the knobs off with force and just unscrew the pots?
 
Oct 24, 2002 at 5:03 PM Post #8 of 14
Possum: If I remember correctly, it's been a while, you have to remove the rear In/Out connector board first.

Get that board out and the main board will lift up from the rear and pull out.

fyleow:

As for changing the gain levels...if you're going to use transformer outputs, then you can just forget about the gain settings for the opamps.

SPDIF in on a stock DIO is RCA.
You can change it to whatever you want.
I ordered my Jensens from Jensen directly.
 
Oct 24, 2002 at 6:09 PM Post #9 of 14
ck42,

Do I have to remove the pot knobs to lift the mainboard out? How do I get those off without damaging anything?


fyleow,

There's a few threads at the Yahoo discussion board that discusses what 4 resistors to change for gain and the 4 corresponding filter resistors (and filter modes). I myself just changed the 4 gain resistors to get a gain somewhere between 1 and 1.5.
 
Oct 24, 2002 at 9:37 PM Post #11 of 14
to remove the main board, remove the screw at the bottom. Pull off the front knobs. Detach the locking nuts which hold the pots in place. Remove the digital board and place somewhere safe. Gently pry the rear of the main board up at the AC connector. Once it is raised over the I/O board, you can slide it back and out. It will still be connected to the I/O board by a ribbon connector. These connections will break. Removing the I/O board as well might help, but get ready for those connections to break anyway. They're present just to torment you, and never miss a chance...
 
Nov 17, 2002 at 7:00 PM Post #12 of 14
So I finally got around to modding the ART past just changing the gain.

-All power supply diodes changed to Shottky's
-op amp changed to LT1362, socketed for switchability
-output capacitors shorted
-input digital and output analog jacks replaced with nice RCA's
-digital input resistor changed from 100 ohms to 75 ohms
-op amp gain and filter resistors changed to the Volks values on the Ray Chau site linked by Hirsh
-capacitor C9 on the digital board was changed to 22uF from 4.7uF, supposedly to help with external sync locking (either for faster or more reliable locking)
-5V regulator replaced with LM1086

-Haven't touched the power supply capacitors yet even though I have the parts. Capacitors are more painful to remove than all the other parts.

Since I can't post to the Yahoo group (they never accepted my membership request yet), I'm trying my luck here with a problem. For some reason, I can only get external sync now. Pushing the sync-change button on the front doesn't do anything. There was no mention of this problem on the Yahoo group related to C9, and C9 is the only thing I changed on the digital board.

Also, are there any opinions here regarding using the Overdamped Butterworth filter (in stock DIO and Volks configuration) versus the Bessel filter? Again, I couldn't download the spreadsheet for the Bessel filter from the Yahoo groups because of membership, so I went with the Vollks values since they were on the website. I'd like to hear the opinion from any headphone users here because, IMO, it's easier to hear changes in equipment with headphones.
 
Nov 17, 2002 at 11:08 PM Post #13 of 14
Nm, I figured out what it was. One of the pins on the digital board wasn't in the socket of the analog board, which is what I was hoping the problem was.
 
Nov 18, 2002 at 7:22 AM Post #14 of 14
IIRC the DIOMODs groups is open membership. You shouldn't need any kind of approval to join. Yahoo may have some arcane requirements, but the groups is open.
 

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