USB DACS-- is there a need?

Onlythat · « **on:** 19 May 2009, 04:29 pm »

Didnt know how to search this topic, so forgive me if it has been done, but I am confused as to the need for a USB DAC whatsoever. I have been using one for a bit actually, so I do have some experience with one (well- two actually)- good sounding, but lately I've been thinking-- there are literally dozens of small boxes for around a 100 bucks or less (blue circle, Bel Canto etc etc) which take the USB output from your MAC or PC and convert it to S/PDIF (RCA/coax) so that you can plug into your 'normal' non-USB DAC and then into the preamp as usual.
They even supposedly make things sound better; clean up the 'dirty' USB signal in the process (see latest positive feedback reviews for example-- the guy thinks all the USB DACs sound better when using the converter and hooking up to their RCA inputs).
Why then all the fanfare about USB DACs from Wavelength etc.? Why cant I just buy a great DAC like an Audio Note or something and use my computer as a server and plug into it via a converter box??? What need for USB DACs then?
Now I am no computer savy guy- so I may be missing something entirely here and I wont be getting any response to this topic on Audiogon-- as YET AGAIN the moderator denied this post for some strange reason. Ooooooohhh --- I feel forbidden posting it here! Sooooo baaaaaad...

Maybe all the USB DAC people would've ganged up on me? Or maybe I am missing something so obvious they wanted to save me the embarassment? Too late!!

chadh · « **Reply #1 on:** 19 May 2009, 05:31 pm »

This might help:

http://www.audiocircle.com/index.php?topic=67188.0

Chad

Onlythat · « **Reply #2 on:** 20 May 2009, 05:12 pm »

Maybe it's my ADHD when reading technical info like the linked thread, but comments such as "it's my understanding that when using the computer's sound card, the card itself is being subjected to all the internal interference when coverting the signal inside the computer whereas by using the USB, you bypass all that interference by having the signal converted outside the box" don't really speak to my question, since I am not talking about using s/pdif out of my computers sound card vs. USB etc.
I guess I am not really asking which is sonically superior either-- USB or s/pdif.
I am asking why, if cheap converter boxes (okay the Bel Canto isnt so cheap) can convert USB signals coming through your computer's USB cable to s/pdif, in some cases even cleaning up the sound in the process, is there a need for many of us to sell our regular old DACs and buy USB DACS?
What then is all the marketing hoopla such as "move into the future with computer audio!! Buy a USB DAC from [your company here] and get with the times!" when it seems to me 89 dollars (a lot cheaper than most USB DACs)will buy you a usb to s/pdif converter and then you can consider yourself officially 'in the future' with no loss of sound quality and according to many, even a gain over a USB input DAC. You certainly have more choices in NON USB DACs!
Now I dont doubt the Wavelengths and Bel Cantos are excellent DACs in their own right- both companies make excellent stuff. But to suggest that USB DACs are 'the future' and all that- when any old audiophile with a regular 'old school' DAC can enter the 'modern day' just by hooking up our usb cables to an 89 dollar converter and then to our regular old DACs as usual- that's what I'm wondering about.
Again- what am I missing?? 'Cause Stereophile and everyone else are reviewing these USB DACs left and right. My favorite reviewer Art Dudley just did so this month and bought the Wavelength. Again, great product, but he loves Audio Note for example- whay couldnt he just get say, a Blue Circle USB Thingie for like 169.00 and hook his macbook's output to that and stick with a regular AN DAC (assuming he had one)?

Tyson · « **Reply #3 on:** 20 May 2009, 06:04 pm »

Basically, using a USB DAC with asynch mode is like using a super high-end cd player/transporter (think Theta). Using synchronous mode is like using the cheapest plastic $79 dvd player from walmart as your transport. Jitter is MUCH higher with synchronous mode, and while some of that can be handled by modern reclocking techniques, the best option, IMO, is to use a method of data transfer that is not inherently error prone (like asynch).

chadh · « **Reply #4 on:** 20 May 2009, 06:09 pm »

I'm no expert, but this is my take on the whole thing (informed by things like the thread to which I linked earlier).

Suppose you have an audio file on your PC and you want to listen to it. You need to pass it to a DAC chip of some sort. Now, there are many types of DAC chips, and one dimension in which they vary is the type of input they use. In some USB DACs, they might use a chip that takes a USB input directly and produces audio output. Other USB DACs may use a DAC chip that takes SPDIF input. That means that the DAC needs to provide conversion from USB to SPDIF as well. Alternatively, one could use a USB DAC that takes the USB signal, converts it to I2S, and then utilizes a DAC chip that uses I2S input. There are all sorts of options available to the designer of the USB DAC.

On the other hand, if you use a little box that converts USB to SPDIF and then use an SPDIF-input DAC, you are committed to this one form or conversion. What's more, you're getting your conversion done by a box that's cheap. And you probably get what you pay for.

By all accounts, Steve Nugent, the guy from Emipirical Audio, knows what he's talking about. He produces a little box that converts USB to SPDIF. But it doesn't cost $100. To do this job well, he needs to employ some serious engineering. So, when you're considering an expensive SPDIF-DAC like an AUdio Note, why would you be satisfied with a cheap, potentially poorly designed USB-SPDIF converter?

I guess the point is that there's more than one way to skin a cat. And potentially, to commit to using a cheap USB-SPDIF converter box seems a strange constraint to impose on yourself, let alone on the market. If you read Steve Nugent's comments on that thread I linked to earlier, his position seems to be that superior outcomes come from using well designed products, rather than from adopting a specific technology for conversion. Hence, the Wavelength DACs etc are expensive not because they are USB DACs, but because they are well designed.

Of course, if one's prepared to accept this proposition, one still has to choose a path. Personally, I thought that the USB-SPDIF conversion alternative just seemed a bit silly. The DAC I use is is Peter Daniel's Audio Sector USB DAC. He produces another equivalent DAC that takes an SPDIF input. I could have spent $100+ on a Trends USB-SPDIF converter and used the SPDIF version of this DAC. But it would have been more expensive in total. And then I would have had to purchase an additional digital cable, and started worrying about the power supplied to an additional piece of equipment, and worried about failure of an additional piece of equipment. Besides, the USB version of the DAC seems to have garnered more positive reviews.

As for the claim that the USB-SPDIF boxes "clean up the sound" relative to USB DACs, it's my understanding that this may be observed in relation to USB DACs that are based on one particular chip that is used widely in relatively cheap USB DACs. But again, if you're prepared to spend money on your digital equipment, there's no reason why a well designed USB DAC cannot be the equal of, or indeed superior to, a well designed SPDIF DAC, especially if you're using a cheap USB-SPDIF converter between PC and SPDIF DAC.

SO if you're sitting at home with an Audio Note DAC, then by all means hook it up to a cheap USB-SPDIF converter. But don't presume that you couldn't have achieved something equivalent, or even better, by selling the AN DAC and buying a single box solution that deals with conversion well.

Chad

Chad

Quiet Earth · « **Reply #5 on:** 20 May 2009, 07:43 pm »

I agree with the notion of using a Dac the way it is meant to be used. For example; Audio Note Dacs are meant to be used with Audio Note transports. The company is not even interested in computer audio playback at this time. When you pair an Audio Note transport with it's appropriate Audio Note DAC, everything sounds right. You have no regrets turning off the computer and just listening to CDs. It works for me, anyway. It's damn good too.

The other kind of DACs that you mentioned are meant for computer playback. Those companies focus on getting the most out of your computer in whichever way they are capable of achieving it. There are some very clever ideas out there too. The only problem that I have with most of them is that they neglect other important aspects of the total D/A conversion beside the one special trick that they do so well. Usually they are focused on jitter and the rest of the supporting circuitry is pretty good to just good enough. (You might even think that some of these guys only listen to the sound of jitter instead of ever listening to music. Kind of sad isn't it?)

So,,,,,,,,,,, the only thing you need to unravel the secret of the hoopla is to decide where you stand. If the computer is your primary pathway to musical happiness, then you better investigate Wavelength, Empirical, etc. But, if it's only a secondary source component for background listening and autopilot, then you've already answered your own question. You don't need it.

Be happy to know that you can live in both worlds. You just have to prioritize. I'm having a blast with my Logitech Duet. It feeds a Monarchy DIP which feeds my Audio Note DAC. (The DIP keeps the AN dac happy when the DUET can't decide what the hell to do.) This is not state of the art in computer playback, I know. But it is fun!

I still like to spin the silver discs too. That's the real deal for me . . . . . .

lcrim · « **Reply #6 on:** 20 May 2009, 08:08 pm »

There is another transfer method that is only hinted at in this thread-ethernet. Four or five years back when I first began playing music from a PC, I found a device that had asynchronous transfer through USB, it then converted the stream to SPDIF. Then I found the Logitech devices and discovered that the noisy (electrical) environment of a PC could be avoided altogether by sending the files through a home network to one of the Logitech devices at the actual stereo system. This also avoided the deleterious affects of the Windows K-Mixer resampling
There are some other ethernet based devices such as the Sonos and now there are the networked media tank devices that have wider sound format applications but still playing back hard drive based files from a remote installation that isolates the mechanical and electrical noises elsewhere. This method still makes the most sense to me from both a costing and esthetic viewpoint.

art · « **Reply #7 on:** 9 Jun 2009, 06:48 am »

I think Tyson has expressed it the best way, so far.

Pat

satfrat · « **Reply #8 on:** 9 Jun 2009, 07:19 am »

Quote from: Quiet Earth on 20 May 2009, 07:43 pm

I agree with the notion of using a Dac the way it is meant to be used. For example; Audio Note Dacs are meant to be used with Audio Note transports. The company is not even interested in computer audio playback at this time. When you pair an Audio Note transport with it's appropriate Audio Note DAC, everything sounds right. You have no regrets turning off the computer and just listening to CDs. It works for me, anyway. It's damn good too.

The other kind of DACs that you mentioned are meant for computer playback. Those companies focus on getting the most out of your computer in whichever way they are capable of achieving it. There are some very clever ideas out there too. The only problem that I have with most of them is that they neglect other important aspects of the total D/A conversion beside the one special trick that they do so well. Usually they are focused on jitter and the rest of the supporting circuitry is pretty good to just good enough. (You might even think that some of these guys only listen to the sound of jitter instead of ever listening to music. Kind of sad isn't it?)

So,,,,,,,,,,, the only thing you need to unravel the secret of the hoopla is to decide where you stand. If the computer is your primary pathway to musical happiness, then you better investigate Wavelength, Empirical, etc. But, if it's only a secondary source component for background listening and autopilot, then you've already answered your own question. You don't need it.

Be happy to know that you can live in both worlds. You just have to prioritize. I'm having a blast with my Logitech Duet. It feeds a Monarchy DIP which feeds my Audio Note DAC. (The DIP keeps the AN dac happy when the DUET can't decide what the hell to do.) This is not state of the art in computer playback, I know. But it is fun!

I still like to spin the silver discs too. That's the real deal for me . . . . . .

Please explain to me why Audio Note has this USB Input Interface option available specifically for computer audio on all their DAC's? What am I missing here,,, or better yet what are you missing here on Audio Note DACS's?

I've heard one of these Audio Note USB DAC's and they do sound damn good,, as well they should for their price point.

Cheers,
Robin

NewBuyer · « **Reply #9 on:** 9 Jun 2009, 03:48 pm »

Quote from: lcrim on 20 May 2009, 08:08 pm

There is another transfer method that is only hinted at in this thread-ethernet... This method still makes the most sense to me from both a costing and esthetic viewpoint.

I'm totally with Larry here on this one. However based on what I've read here and elsewhere, I would also like to try some async USB DACs sometime, just for fun and comparison (and also Pat's new Legato device)...

Quiet Earth · « **Reply #10 on:** 12 Jun 2009, 02:28 pm »

Quote from: satfrat on 9 Jun 2009, 07:19 am

What am I missing here,,, or better yet what are you missing here on Audio Note DACS's?

Sorry for the confusion satfrat. I guess I should have specified AudioNote UK finished products,,,,,,,,,, not Audio Note Kits. The picture you show is from the Kits division.
Audio Note Kits are a little more experimental (hence, kits) than the UK finished product company.

satfrat · « **Reply #11 on:** 12 Jun 2009, 04:09 pm »

Quote from: Quiet Earth on 12 Jun 2009, 02:28 pm

Quote from: satfrat on 9 Jun 2009, 07:19 am
What am I missing here,,, or better yet what are you missing here on Audio Note DACS's?

Sorry for the confusion satfrat. I guess I should have specified AudioNote UK finished products,,,,,,,,,, not Audio Note Kits. The picture you show is from the Kits division.
Audio Note Kits are a little more experimental (hence, kits) than the UK finished product company.

See there, I knew I had to be missing something. I can't say one way or another tho if the Audio Note USB/Dac I heard was a kit or not but it did sound really good and it came from a USA Audio Note dealer,,,, the one and only,,,, Lizard_King.

Cheers,
Robin

evan1 · « **Reply #12 on:** 12 Jun 2009, 09:07 pm »

Robin
they are a kit but they put it together for you. Thats what the guy said at Mike's last week

PaulFolbrecht · « **Reply #13 on:** 13 Jun 2009, 03:01 am »

I've got an AN Kits DAC 2.1C Sig which I built. I use a Mac Mini into its USB input (which is just the Hag board). It is the best digital I've ever heard with the exception of a few very well-done SACDs on a very good SACD player.

However, according to AN, the AN transports are even better, and I bet so. But I want to stick with computer audio for the ability to do 24/94 (well, 18/96 which the DAC supports); I am strongly considering picking up an Emperical Off Ramp to do just that.

I can report back unless nobody is interested in how it sounds.

cryoparts · « **Reply #14 on:** 13 Jun 2009, 03:32 am »

Quote from: PaulFolbrecht on 13 Jun 2009, 03:01 am

I use a Mac Mini into its USB input

(well, 18/96 which the DAC supports)

The USB input only supports 16/48, are you saying the DAC through the S/PDIF only supports 18/96?

Peace,

Lee

Quiet Earth · « **Reply #15 on:** 13 Jun 2009, 03:45 am »

Here is an excerpt from my AudioNote (UK, finished product) DAC manual :

Our converters all use a high grade selected Analogue Devices AD1865, 18Bit stereo converter chip because we found this chip to be the best sounding available (yes, even better than the 20Bit and 24Bit versions!). This is fully compatible with 16-bit 44.1kHz technology as well as 48kHz and can also be used with the 24-bit 96kHz DVD-A standard as the DAC chip will only loose resolution at the 20th, 22nd and 24th Bit, a truncation that mildly reduces the resolution.

cryoparts · « **Reply #16 on:** 13 Jun 2009, 03:51 am »

Cool, thank you. I've heard AN gear many times over the years and always thought it was quite good.

I wasn't familiar with their design, I guess a quick Google could have solved that, huh?

Peace,

Lee

Quote from: Quiet Earth on 13 Jun 2009, 03:45 am

Here is an excerpt from my AudioNote (UK, finished product) DAC manual :

Our converters all use a high grade selected Analogue Devices AD1865, 18Bit stereo converter chip because we found this chip to be the best sounding available (yes, even better than the 20Bit and 24Bit versions!). This is fully compatible with 16-bit 44.1kHz technology as well as 48kHz and can also be used with the 24-bit 96kHz DVD-A standard as the DAC chip will only loose resolution at the 20th, 22nd and 24th Bit, a truncation that mildly reduces the resolution.

Quiet Earth · « **Reply #17 on:** 13 Jun 2009, 04:21 am »

No problem Lee

I think that most of the non-oversampling dacs that use the CS8414 digital receiver chip can accept from 16 to 24 bits, and any rate of 44.1/48/88.2/96KHz. For example, I know this is true of the MHDT labs constantine DAC too.

PaulFolbrecht · « **Reply #18 on:** 13 Jun 2009, 02:23 pm »

I see the question about the AN DAC chip has been answered - 18b.

BTW, SACDs on my Marantz SA11 have as smoothness that eclipses the AN DAC at 16/44, but the AN DAC is more dynamic. And playing redbook the Marantz does not come anywhere near the AN DAC - it sounds veiled, thin, and congested in comparison.

But those SACDs are good!!

rwdrey · « **Reply #19 on:** 16 Jun 2009, 03:51 am »

Absolutely, there is a need! I'm all for choice & simplicity. By your own admission you've had 2 that sounded good. The best is subjective & a moving target. The USB interface is new compared to SPDIF, & will improve greatly over time. Is the USB interface the best, probably not at the moment???? After 30 years in this silly hobby I am enjoying music more than I ever have, thanx to a USB DAC, a HP laptop, & a big ass HD. Buy one of Lee's USB cables to get alittle more.
Rich