Digital "Crispies" and the ART di/o


I was listening to Glenn Gould playing Bach Goldberg Variations (1981 recording - Sony Digital) the other night, through an Arcam Alpha 7 and ART di/o DAC and on track 17 I noticed this static, "crispy" noise along with the piano notes. Maybe it's the dac, I thought, so I hooked up the preamp to the analog out of the Arcam, and the crispies weren't there. Neither was the soundstage, and alot of timbral detail. My question: are the crispies digital dust in this recording that the ARCAM DAC did not reveal (I've only heard them on 2 tracks), or could they be lack of power in the ART di/o (I'm using the wall wart power supply that came with it), or maybe my new speakers (thiel 1.6) breaking in.

Thoughts?

Thanks!
robertd
Which input sampling rate is your DI/O set to? If it is not 44.1 then that could be the problem and if it is the external mode then you may be losing the digital lock. The DI/O doesn't have a very wide window of tolerance in the ext. (green LED) mode. Then again, there is always the possibility that something is wrong with that particular CD. Has this happened on other CDs also?
I've heard this in ART DI/O units, but haven't been able to pin it down and haven't had the chance to ask around as you are. I would notice it only on specific tracks, and it appears to be towards higher frequencies when it shows up.

My question to you, do you notice it more or less at different ART settings? (ex. X2, vs internal lock, vs external lock)

Secondly -- When you're looking at the front lights, does your lock light go on and off through a track alot? Do you find that your red light, the one I believe is actually for A/D, goes red a lot?

I know there is a DIOMODS group on Yahoo that I've yet to look into, you might want to inquire there -- plenty of folks that know the product in and out.

I think this was asked already, but is your unit modified at all?

If you do get an answer outside of these boards, please drop an email!
A 1981 digital recording is an early digital recording...that may be the problem. The DIO may be passing along more info, which may include more low level info, but it may also include flaws in the recording or engineering. It's hard to say without hearing the sound.
I have a stock, unmodified DI/O with the upgraded Stancor power supply. I am using aftermarket line attenuators to reduce its output to 2 volts so I have been able to use my MIT and Harmonic Tech interconnects with it.
I have found that it emits RFI and the static/grainy sound that you mention does show up on certain recordings with certain digital cables. I listen primarily in "X2" mode and have not been able get the "external sync" mode to work with any transport (3) that I have been able to try.
I have found that if you leave the tube installed and use either an Apogee or Canare digital cable that the problem seems to go away. Your mileage may vary here. I am well aware that the tube is supposed to have nothing to do with the D/A conversion but my DI/O sounds slightly better with the tube installed as opposed to removed. I have also installed 75ohm shorting plugs on the analogue inputs and digital output, which has helped a little with the RFI (but it still emits some).
As for its sonic performance (stock), it is worth every nickel of its street price, but alas, I am afraid it is not a giant killer. I do prefer it to the MSB and Audio Alchemy dacs that I have heard in that the DI/O is a little smoother and has decent bass response for a budget piece. It is a lot of fun to play around with. I have been experimenting with the a/d/d/a converison at various tube warmth settings. However for serious listening, my 1996 Micromega DUO BS2 will beat it in almost every sonic parameter. My stock DI/O is a bit rough sounding in the upper midrange and it does not image very well. Some violins sound a bit "steely" and some voices do not sound as natural compared to the Micromega. If the modifications that are being offered address these weaknesses, then this could be a tremendous bargain.