Importance of computer for DAC shootout

I am using a perfectwave DAC + bridge + modwright 36.5 LS/PS preamp to stream flacs over my network. Very happy with the sound, but intrigued by the idea of getting better SQ for less $$$ I will soon be auditioning an Antelope Zodiac Gold + Volticus over USB, directly into my poweramp. Being able to take out the modwright alone would pay for the new DAC. My only concern is the Computer I will be using for this shootout. I have a Dell laptop and an Asus media PC, both with USB 1.0.

If I opt for the Zodiac I will go all out on computer source (may be mach2music), but I don't want to invest before knowing if I even want to go down the USB path.

In you estimation, is there any chance of the computer used in my shootout distorting the outcome? Would I be better off using my Marantz ud9004 S/PDIF source for the Zodiac, and then get a better computer if the Zodiac wins the contest?

Or are the difference between computer sources small and will I be able to conclude which is the better DAC using a mediocre PC as the source for the Zodiac. Any advise on how to set up the hardware for the shootout is welcome.
For starters you might want to test file types and player programs. On my system I notice a distinct and repeatable difference in them (alac,flac,aiff and wav). Yes, I realize that there should be none, alas.

If your system can resolve those differences, there is a good chance that you will realize the benefits of other cpu related changes- just as with a turntable.

I am sure that someone will chime in here stating that I am a fool, and bits are bits. FWIW, I was very skeptical before I did the test. In fact, I needed to do the test three times over months before I would believe (in) it.
IMO performing the comparison with a computer that pre-dates USB 2.0 (and even USB 1.1, if your statement is correct) will tell you little or nothing about how the DAC's will behave with a modern computer. I would also be hesitant to extrapolate from results with your Marantz player.

You may find my post here to be of interest. Although it deals with transports rather than computers, depending on the particular DAC design similar considerations may be applicable.

-- Al
I need to check my configuration. If it turns out my Dell Laptop or Asus has USB 2.0 should I be OK?
All PCs are notoriously noisy platforms that interfere with the sound that comes out of them. They are great for ripping, storing, etc. but they are not the last word for playback. Make sure you have a really good media player that can isolate and run the playback while shutting off other programs that compete with the sound (I believe its called 'hog mode'--I'm still very new at this).

Without a good media player, all will be for naught.
10-12-11: Edorr
I need to check my configuration. If it turns out my Dell Laptop or Asus has USB 2.0 should I be OK?
That would be a lot better, but I think that using a computer that is several years old or more would still make the meaningfulness of the comparison very questionable.

In fact, based on the kinds of unpredictable interactions that can occur between a DAC and a digital source, such as those I cited in the post I linked to above, arguably it would be a good idea to perform the comparison with TWO modern computers (if neither is the one you would end up using).

Perhaps a reasonable compromise, though, would be to compare using the more recent of the two computers AND using the Marantz player, and seeing if you get consistent results.

Best regards,
-- Al
What is your preference in file types? What were the differences you heard?
In my experience, I think the chances of you getting a meaningful result with either of these computers is about.....


Beg or borrow something...
Depressing news guys - but good to know in advance and not screw up my shootout. I just made an offer on the Mac mini listed on A'gon. That should solve my problem for the shootout. If I end up keeping the Zodiac, I can either get this Mac upgraded to mach2music specs or sell it and get a 2011 mach2music model.
Mach2 is a good choice, however comparing USB DACs is dominated by the quality of the USB interface and master clock.

If you read the last 3 or4 DAC reviews by Steven Stone in TAS, you will see that once you provide the DAC with a really low jitter digital signal, they all start to sound very similar. The diference in a 1K DAC and a 6K DAC becomes quite small.

Steve N.
Empirical Audio
There are so many conflicting opinions and observations about what it takes to turn bits into a good analog signal I have no clue what advise to go by. You can spend over $3K on the latest mach2music with external powersupply and audiophile USB cable, while your DAC manufacturer will tell you your asynchronous USB DAC is pretty much immune to the source anyway. You can spend 10K on a tube preamp and your DAC manufacturer will tell you taking it out of the chain will improve SQ. So I only go by personal observations in my own system - I have no experience with USB DACs but in my experience DACs in general make a huge difference (transports not so much). Just want to give the Zodiac Gold a whirl, simply because it gets good press and it would pay for itself if I can take out my preamp. If it does not deliver the goods it is up for sale in A'gon. How far I need to go optimizing my digital source is still a shot in the dark for me, notwithstanding all the advise I have been getting. I'll probably get a mini mac to be safe and upgrade to mach2music if I decide to go the USB route.
i'm not a usb fan but won't open that can of worms in your thread. i recently compared a macbook pro to my win7 pc and found no difference what so ever (streaming with both). not sure if the mini has any advantages over the macbook so i can't comment on that. do agree with others that using an old pc is not a good idea.

comparing file types, i found flac and wav superior to aiff and alac. wav and flac were identical to my ears.
I just got the Mac Mini at a price I can resell it for in a heartbeat so no exposure there. I will be using pure music with Flac's.
As important would be to make sure the computer is on
a different power circuit to the rest of the hifi. Keep it isolated so
you don't add noise.
I am using 2 PS audio P5 regenerators, which provide isolation. I would assume this should be OK.
Have you considered using a network player like Squeezebox Touch as the source to the DAC?

That would effectively take the "computer" out of the sound making process. Squeezebox is designed for use with good audio gear. Most home computers including laptops are not.

You would connect the network player to teh network either using a wired or wireless network connection and then the player streams the music files over the network from the music server (ie your laptop running the media server program, say Squeezeserver in teh case of Logitech Squeeze players) as needed.

That is what I would recommend to take the computer out of teh music making process. I have used this configuration with everything from a 8 year old Dell laptop to much newer laptops as the server and do not hear any audible differences, although I would recommend a faster or more modern laptop with 4Gb of memory or more in order for server related operations like music library scans, searches, etc. to run faster.
Never thought about it. Call me an audio snob but I am deeply sceptical of $300 devices being able to perform at the level of mac based music server architectures, used by computer audiophiles the world over.

Now, if they stuck their product in a heavy brushed aluminum box, called it the "Squeezebox reference" and charged $2000, I would definitely have considered it :) (provided it would accept a $500 aftermarket powercord of course).
"Call me an audio snob but I am deeply sceptical of $300 devices being able to perform at the level of mac based music server architectures, used by computer audiophiles the world over. "

Well, one is entitled to be skeptical but I suspect that one would be mistaken.

What is it exactly that makes a mac based music server architecture so special again for audiophiles?

Actually the DAC in the latest Squeezebox Touch specifically is rumored to be pretty good but I have not even tried it in that I had my DAC nailed down prior to going with the Squeeze devices.

A Mac based music server is fine. Squeezeserver runs on Macs, PCs, and other OSs, so you can use Squeeze players and your DAC of choice with a Mac music server.

But if the "mac based music server architecture" is so good, why use a third party DAC at all? Just use the one in the Mac and be done with it.
We're going off on a tangent. I have a phenomenally sounding PS AUdio Perfectwave DAC, streaming over the network. I am just intruiged by an reportedy very good altenative DAC with analog volume control. I want to make sure the computer I use to feed the DAC over USB is not the "weakest link" potentially distorting the outcome of a shootout. To this end, I bought a used Mac for a price I can easily resell it for. I think I'm all set.
I suppose it depends on how well the mac works out then. I'm hoping it does.

But to answer your question I am also saying that the choice of device feeding the DAC and the intereface used can make a difference in the sound. If the Mac or other computers via USB does not pan out, then I would recommend considering the Squeezebox Touch feeding your DAC as a very robust alternative in your case.
OK - thanks. Don't get me wrong - I appreciate all the advise I am getting here. I placed my bet on the Mac Mini. Next let's see who wins the shootout. If its a close call I may try some other USB source, but most likely I would get an external powersupply for the Mac first to see if that would swing the vote. I guess I should also get at least a half decent aftermarket USB cable. Damn, this never ends....
Why USB? A good soundcard w/spdif out will blow away the usb (unless you spend mega bucks (and still...). Don't limit yourself to usb, it's the poorest interface. Try different sources and you can easilly hear the problems with usb.
From what I have been reading the current vintage of asynchronous USB DACs have closed the gap with other interfaces. However, I will have a good old transport on standby to hear for myself.
All blanket statements are inherently incorrect.'s that for a blanket statement?

The interface implementation is paramount, whatever the interface. Jitter reduction is what most of hear as differences between transports/interfaces. There is hope though....all digital is improving as designers understand more and more as well as the trickle down of technology advances to more affordable levels.
dCS streams PCM and DSD via USB and from what I've heard, the sound is up there with the best of them. There is a lot of misleading marketing going on with digital.
Case in point: "the length of a USB cable can't exceed 3 meters". I've read that a lot and yet I have a 5 meter length of Wireworld USB cable that begs to differ.
Its what at the receiving end that matters.