Are most DAC's compatible w computers?

I have an SPDIF output that comes directly off my harddrive on my windows xp based computer. I also use windows media. i was thinking about inputing this into a tube DAC to both increase the sound quality and flexibility in my system configuration.
I wanted something fairly inexpensive... I would like to spend $300 or less and have been looking at Cal Labs Sigma II.

Is this straightforward no brainer kind of stuff or is there something that I'm not thinking of... like compatiblity issues?

I would imagine it will work, BUT my experience has been that the sound of the DAC is extremely dependant on the level of timing jitter coming from the transport, unless the DAC reclocks the data. If your soundcard has low jitter and a good SPDIF interface it could work well. If the soundcard has high data jitter then the DAC alone may offer very little improvement.

Reclocking in DACs under $1000 is a relatively new phenomenon, but you can achieve the same by buying a Monarchy DIP or similar jitter attenuator. They are around $100 used.

So what I'm saying is that you might find that adding the DAC makes surprisingly little difference to the sound quality, but if you were then to add a jitter reducer ala Monarchy DIP between the computer and the DAC then the sound quality will be very much better.

The least expensive reclocking DAC I am aware of is the Benchmark DAC1 at $900. This DAC is said to be quite independant of transport quality.
Straightforward. The only problem can be hum due to ground loops between the computer and DAC ground, but will not happen with all systems.

Steve N.
Empirical Audio
The short answer is "yes". If your soundcard has an S/PDIF output then you should be able to hook it up to any DAC with an S/PDIF input and it should work. Sean's points about reclocking are to the point as well. You are using your hard drive as a transport when you use your computer. If the clocking is off when it sends the signal out, and it is not compensated for in the DAC or in some kind of jitter device in between, the effect on the music can be profound. Though it may sound OK (like actual music coming out of your speakers) the potential loss will be in the PRAT aspect of the music. You may find that your foot just ain't tappin' anymore!

Either get a DAC with superb clocking, or, perhaps one of the pro-DAC's with USB option like the Apogee DAC. Rumor is that Benchmark is working on that option as well. USB is a bi-directional interface which allows clocking information to move both ways. In some cases, as I understand it, this can be of tremendous benefit in eliminating jitter. I'm not sure if this is the case with S/PDIF. If you went with a USB DAC you would be bypassing your sound card altogether.

I've been experimenting with the same technology having ripped all my CD's to a 250 gig HD. I'm currently running my laptop to an ESI Waveterminal U24 USB device, digital out via S/PDIF to my Muse Model 2+ DAC. Results are superb. I do believe the Muse does have excellent clocking. I've never tried the DAC in the Waveterminal (it does have that option), but don't imagine it's going to compare well with the Muse. I'm not sure if the Waveterminal does any jitter attenuation at all via the digital throughput - does anyone know?

I just spoke with Benchmark and they said there is no USB version coming around the corner. They said that it would be much more expensive than using the DAC1 with a simple USB/SPDIF converter like the M Audio Transit ($75), so it's not cost effective. And because the DAC-1 is jitter immune, there is no problem using the Transit with whatever digital cable one might use.
In my experience - and I am a Mac guy, not a Windows guy - it will work.

But this is also a bit like saying cables are cables and tubes are tubes. Meaning that while it will work, it is probably not the best way to get where you want to go.

There are many posts in PC Audio on the subject and also on the Asylum. To summarize, the consensus seems to be:

The computer environment, with its switching power supplies, disks, RAM etc is a nasty environment. Getting the signal out of the box before processing it is universally seen as highly desirable.

There are a number of ways to do this:

- USB out via something like Waveterminal or directly to the DAC is a universally acclaimed solution that seems to work very well for everyone regardless of operating system.

- SLIM ( can be connected via either WiFi or ethernet, have a DAC built in and also offer SPDIF out

- iTunes/Air Express solutions are working for some where line of sight is practical

In general the consensus is that a wired distribution solution is preferrable to a wireless one

SPDIF is often as big a problem as anything in the chain - for this reason Mac offers optical (Toslink) outs - of course you can find ample contention about the Toslink sound - but not about the Toslink signal....

BTW while much is made of the two way nature of USB, I can't find anything in the technical descriptions that supports the theory that USB does anything about jitter - the two way function is its device communication and control protocol - take a look at

There is no doubt that the way you rip is critical. Lossless or no compression and error correction are the keys - format preferences vary but Apple Lossless (iTunes) and .wav are the preferred audiophile formats. EAC and iTunes seem to be the top choices.

Jitter is not a problem in ripped material. Jitter is an artifact of the electro-optical-mechanical process called playing the CD - a by product of trying to read data from an imperfectly reflective spinning disc at ever changing speeds in real time with a motor. In contrast all a computer has to do is retrieve relatively small chunks of data relatively slowly.

The fact that they are still having "jitter-like" problems seems to be why a lot of people are starting to think that SPDIF is the weakest link in the chain. This is the appeal of the USB direct to DAC solution.

Finally there not much question as to whether you will more readily achieve a tube sound at the DAC or the preamp - consensus is that the preamp is a better and potentially less expensive place to do this. And how often is something better and cheaper...

That said, you might want to check out the much awaited Scott Nixon TubeDac with USB input due out any week now. If what you want is audio from a hard drive this is probably a better long term investment than the Cal.

Achieving excellent results from a hard drive source requires paying attention to all the usual things - power, cables, placement, room tuning etc.

You will find 100% consensus that properly executed this is an extraordinarily cost effective way to get great playback. Doing this right is equivalent to a major component upgrade.

And it is the only way to manage a large library... simply fabulous from that perspective, SLIM and iTunes are the leaders in that category

Hope this helps
I am using a G4 laptop out to a Waveterminal 24 ($159) and the Waveterminal directly into my integrated amp. The sound through the Waveterminal is at least as good the sound of my MAC changer (maybe a little better). I am trying to decide between the Benchmark DAC 1 and the Apogee USB DAC -- as a further improvement in sound. Any thoughts between these two DAC's? Using the Apogee means I don't need the Waveterminal, but the Benchmark has also received so much acclaim.
I just tried using my pc with an external d/a. For the cost of a d/a along with the crummy quality of the pc, you are much better off just buying a decent cd player.
To get good sound out of a pc will cost a bundle. You need quality software for burning, more internal dampening, huge hard drives and.....I tried to bypass the sound card with a usb run dac and was totally disappointed with the quality.
BTW while much is made of the two way nature of USB,
I can't find anything in the technical descriptions that supports the theory
that USB does anything about jitter - the two way function is its device
communication and control protocol - take a look at

Quite correct, USB does absolutely nothing about jitter in and of itself. It
must be the device that is connected via USB that is built do take advantage
of the bi-directional nature of USB that would do something about it. Take a
look at the information provided by Gordon Rankin over at Wavelength on the
subject here

To get good sound out of a pc will cost a bundle. You need quality
software for burning, more internal dampening, huge hard drives and.....I
tried to bypass the sound card with a usb run dac and was totally
disappointed with the quality.

I don't agree, and am quite curious why you couldn't get satisfactory sound
from your setup. Which USB DAC did you try Elevick? As far as the cost; Most
of us already have a capable PC or we wouldn't be posting here. It does not
take an extremely fast PC to stream music, nor does it require a whole bunch
of RAM. A Waveterminal is currently around $159 and will connect any USB
equipped PC to any DAC with either S/PDIF or Toslink inputs. The only other
investment would be in an external drive to store the larger files (a 250GB
Lacie drive is about $219) and most folk's entire collections would fit on that
single drive in Apple Lossless. Total investment is about $400. In
comparison to what folks on this site spend on front ends I'd say that is a
mighty small sum. Even if you add $1000 for the computer itself you are still
at the price of a nice front-end CD player or entry level turntable rig. Oh,
and iTunes is absolutely free and is excellent software for ripping and playing
your collection. Using this system through my Muse DAC the sound is
nothing short of superb, and I find no advantage to running playing a CD
through the same DAC - I am quite sure that an A/B/A comparison would
leave anyone stumped. I'd challenge anyone here to consistently identify one
from the other. As has already been said, the tremendous convenience of
having your entire music collection at your fingertips is priceless!
Perhaps this is getting off the topic, but all I want to accomplish is sending WAV or FLAC files from my computer to my Alesis ML9600 HD. I download a lot of digital soundboards and instead of burning them to a CD then playing or uploading them on the Alesis, I'd like to play (or transfer if possible) the files on my computer to the Alesis which will allow me to record them as 16, 20, or 24 bit and 44.1, 48. 88.2, or 96k (uploading from CD is 16/44.1).

My computer only has USB, SCSI, LAN, and Firewire connections. Can anyone give me some idea if what I want to do is possible or how I can go about it. Alternatively, I can transfer the lossless files to my Rio Karma which as analog outputs. I suppose I can hook these into the Alesis inputs and play the music on the Rio while it records on the Alesis. The sound on the Rio is pretty good, but would I have to worry about jitter?

To Jax - I agree with you. But you know I am amazed by this Rankin fellow. At your recommendation, I read his website again - especially the following:

"On power up of the computer the 2 devices negotiate services... Since the USB receiver only has to handle these 3 frequencies, the clocking to the separate DAC IC has almost no jitter... Therefore the jitter problems of SPDIF almost go away using USB."

I did pass Logic and this ain't it. All this says is what we know, USB does not introduce jitter when transporting the signal from the PC to a device. Of course if I was going to charge $14K+ for a USB DAC I would be working hard to think of a good benefits statement too!

Pardales this is the real reason you might want to consider a USB DAC - because it eliminates the chance that the SPDIF from the Waveterminal to the DAC could introduce some error. Simple is most often better - getting rid of cables and connectors usually is. Plus you eliminate the cost of the Waveterminal and a good to great SPDIF cable... One reason I upgraded to a G5 is to run Toslink directly from the computer to the DAC - still evaluating but its pretty impressive with the Wireworld 5 Supernova

Please note that nowhere does Rankin say that there is any kind of error correction of the audio data during playback... I keep reading and hearing from people that think this is what is happening and I am puzzled as to how this got started.

And contrary to his site, there is most definitely a USB 2 standard which is why there are a billion plus USB devices worldwide -

Folks - you do not need to spend this kind of money to get awesome sound from your hard drive - you just need to sweat a few simple details, like anything else in our hobby. This is truly high end for the rest of us...

One last thought - if you have a G5 or a PC that supports SATA I strongly suggest you use it instead of Firewire to connect your external hard drive(s). It is vastly, infinitely, amazingly more robust and not a bit more expensive. Hard drives from the usual suspects at the usual places at ridiculous prices. Instant set up, you no longer even have to set jumpers.

Savvy vendors in this space with helpful websites are and You will be absolutely delighted
Ckorody - Thanks for your point of view. Don't get me wrong, I was certainly not recommending (or discouraging) that anyone go out and spend $14K on a USB DAC. I'm not sure where you are getting that price. The two USB DAC's Wavelength offers are the Cosecant at $3500, and the Brick at $1750. Both are tube-buffered USB DACs. The only reason I pointed to the site was for the explanation of the two-way nature of the USB interface. I've never heard any of their products. Should you care to take your puzzlement directly to the source I believe Gordon Rankin is a frequent contributor over at AudioAsylum you could publicly ask him yourself there, or, of course, send him an email. It does make sense to me (obviously)...if there the information is going just one way there is no reference point to the accuracy of delivery from the origin. If two way the device has the potential to check the accuracy of the origin and adjust (buffer) accordingly. It sure seems logical to me. I completely agree that you do not need to spend a ton of money on this technology to get very rewarding results. Thanks for the links too!

Another note as an addendum to your post: The Waveterminal does utilize an internal clocking device. The feed from computer to Waveterminal is indeed USB. From there you can go via either SPDIF or Toslink to your DAC. I've done no comparisons to a USB DAC, but compared to my Muse transport hooked up to the Muse DAC via their proprietary connector (optimal for those two units). FWIW I cannot tell the difference between a CD on the transport and the signal delivered from the hard drive via the Waveterminal (either in Apple Lossless or WAV), at least in the system as it is hooked up in my home right now (currently at somewhat of a compramise in room treatment). I'll be curious to do the same test in my main system, which is currently not set up due to a renovation.

Thanks, Ckorody. You are right that a USB DAC would be a simpler path than adding a DAC via the Waveterminal. Are there any other USB DAC's worth considering besides the Apogee (without breaking the bank)? Thanks,
Good stuff.. thanks to all.
I just figured out that I can get lots of great radio through my computer as well. I can now sell my changer and tuner if I want. I am thinking about putting my money towards a really good DAC since my computer is turning out to be the heart of my system. Now that I have ripped my 500 cd's to computer, and have all the album artwork loaded as well, I can't believe I didn't do this sooner. I am rediscovering my music collection and listening to stuff I haven't listened to for years. It would not surpise me if we begin to see a lot of USB DAC's on the market very soon.
Hi guys -

I agree this is the future - I keep flogging the USB DAC idea - powered by iTunes and 6 billion downloads a year versus a declining CD market it seems a no brainer at many market levels...

I too have had excellent results with the Waveterminal - so clean and simple and no power supply. Sorry about the misquote on the Rankin products, I guess you would have to consider him a possible USB DAC - not too much else out there that I am aware of but you should check out

The gentlemen is a former Intel engineer and a big time modder who is one of the first people I ever corresponded with about the USB direct issue

Great thread - kudos to all
This is the thread for which I've been looking. GREAT info. I've decided that hard drive to DAC to stereo is the wave of the future and it's here now.
The key is to have a soundcard that has ASIO driver.
That will allow the music data to bypass the whole windows directsound architecture. You will essentially get a bit perfect stream of your data file. (a good rip is obviously the key to have a good data file)


use a USB DAC, like the Apogee MiniDAC.

Either way you will get very good results. (in fact perfect) if your sound card does not have ASIO drivers however, the quality cannot be guranteed.
What about the Xitel HiFi-Pro Link? Rave reviews and it seems to offer the same USB capability plus all the necessary cables. Just the cost of the cables might be worth the $99 price.
Is there a paticular version of Waveterminal that I should look for or just their latest?
I think their latest is the least that is what is currently on their interet site. It really is a nice product.