IROC DAC or PS Audio Ultra DAC / Digital lens

I am exploring DAC's for My Mini Mac computer based music server the PS Audio Ultra DAC / Digital Lens and Larry Moore and his IROC . These are the two products that look most interesting to Me as of now . I was wondering if any people who went to RMAF had a chance to hear both of them and any thoughts.I did have a chance to hear the IROC once at a Cincinnati audio club meeting but this was before I set up My own music server. I would be using either optical [ Toslink } or USB out of the Mini Mac I just copy CD'S to My hard drive in AIFF and have no Hi Res downloads just looking for very good sound.I may in the future want the ability to do Hi Res files 24/96 but that is down the road a little bit I am still learning all this upsampling /oversampling /24/96 / 24/192 ect. just trying to figure it all out. I now use a older Cal alpha DAC with 24/96 upgrade and a Toslink cable sounds good but know there are better DAC'S out there. Thanks for any thoughts Marc
The PS Audio Ultra DAC will not be released until some time next year (probably in the first 4 months they tell me). Their new Digital Lens will come later. The iROC is being discontinued in favor of Larry's new MusicStream DAC, which is about double the price. You may be able to locate a used iROC. Be aware that it is USB only, so you will have to use USB out of your Mac Mini, not Toslink. I have an iROC on the way and can comment in a week or so (I also use a Mac Mini).

Both the PS Audio and Larry's new MusicStream will use the CEntrance USB software, and Larry's will also use some of the Empirical Audio technology. These, along with the Wavelength DACs and a few others, should raise the bar considerably for USB DACs. You'll probably be limited to 24/96 with them, although, technically, USB can accommodate a higher sampling rate.

I really like the iRocs I have on a couple of systems using the MacMini.

btw, the USB cable of your choice matters.

I have a couple of Ridge Street Audio USBs (and one CryoParts USB on a less critical system), and I'm very happy with both. The RSAs are exceptional imho.

I've found the iRoc to be completely trouble free, very musical, very listenable, with no listening fatigue related to the iRoc itself.

Talk to Larry Moore; I've found him to be very personalable, informative, knowledgeable and helpful. He is extremely fair-minded regarding the competition but is also very focused on the quality audio experience.

This is his email:

and his phone:

(513) 697-1187

:) listening,


I have owned the iRoc for about a year. I used to own a Wavelenghth Brick and Cosecant (non-async version) as well as the Bel Canto DAC 3 and the iRoc blows them all away. I recently upgraded my iRoc to the new MusicStream and have logged about 20 hours of listening.

As is the case with most audio gear, the MusicStream probably isn't twice as good as the iRoc. I'm hearing instruments and vocals that I haven't heard before in recordings that I've listened to hundreds of times. I'm attributing most of this to an improved soundstage. This is saying a lot as the iRoc has an impressive soundstage. The MusicStream and iRoc share similar sonic characteristics which is a good thing as the Ultra Fi USB DACs are much more dynamic than other USB DACs that I've owned or heard that tend to be flat and lifeless.

In summary, if you can afford the MusicStream, then IMHO this is the current king of the USB DACs. If you're on a tighter budget, then I'm confident that the iRoc will not disappoint.
My $.02; go cheap and/or used for right now and wait for the consensus to develop around some of the newer products and technologies.

PS Audio's new Ultra DAC has the potential to be a game changer with it's ability to handle any and all resolutions and it's use of I2S interface. If I remember correctly, they said it would be around $2,000 at the RMAF. I listened to the MusicStream at the show too, but the room was so overwhelming I couldn't give a good evaluation of it (trying to show off the Dodd amps and LS9 monster speakers, they had the volume way too loud).

My favorite USB DAC of the show by far was the asynchronous Cosecant by Wavelength. It sounded practically jitter free and I just melted into the chair listening to it. I could have stayed for hours. The price tag is about the same as teh MusicStream (~~$3,500 U.S.).

For the record, I currently have a PS Audio DAC 3 with the Cullen Circuts Level 3 mod. A nice unit and great 'bang for the buck' ($1,000 plus $600 mod), but not on par with the three above.
I picked up a used iRoc last week. I take back every bad thing I've said about USB audio. Holy crap, this thing is great!
iRoc vs. Musicstream: I've had the opportunity to listen extensively to both. The iRoc is a special DAC. If you need a modestly priced DAC, get an iRoc and call it "Done!". It doesn't merely do very good digital, it does exceptional music.

If you need something that rivals or exceeds the virtues of a top flight analog front end, get a Musicstream. It's absolutely superb and not a small step up from the iRoc!

Shazam, wished you could have heard the Musicstream in the context of our room/system at RMAF. Sonically, we weren't trying to spotlight any particular piece of gear but rather present a musical system where you could appreciate the virtues of a given piece of gear in regards to its contribution in a system. In that context, I believe the Musicstream shined and, while I wouldn't say we had the "Best" room at the show (I don't think anyone had a "best" by what I heard...), we did have one of the more enjoyable rooms evidenced by quite a few folks who came back more than twice for an extended listen. This was no small thanks to Ultra Fi's electronics contribution.

Short of it: Depending on what you're willing to spend, you'll do very very well with either.

Disclaimer: I have no business interest in Ultra Fi. Mr. Moore and I have simply become fans admirable of each other's work.


Drubin... yeah, baby, the iRoc is just incredible! I agree entirely...

btw, RSA's Poeima cables are also excellent stuff... my iRocs were transformed with them.

:) listening,