USB 3.0 DAC - Let The New Revolution Begin!

[logicsound]

I have been looking for the first DAC to incorporate the revolutionary USB 3.0. If anyone hears of one - even in development - please post. The 3.0 standard is not just a minor upgrade but a major revolution. The data throughput rates and 2 channel async design will eliminate most of the problems with USB 2.0 (poor real world throughput - forget those theoretical limits). For those looking for a standard USB DAC to play MP3s or 16/44 wave files don't bother, but if you are serious about hi rez (32/192 or higher) or umsampling you should wait until DAC with USB 3.0 are available.

 

Advantages to USB 3.0:

 

* Real world data throughput of 3200 Mbit/s vs 240 Mbit/s.

 

* True Async dual channel communications - not a work around

 

* New host controller architecture - dual controllers

 

 

The host controller directs traffic flow to devices, so no USB device can transfer any data on the bus without an explicit request from the host controller. In USB 2.0, the host controller polls the bus for traffic, usually in a round-robin fashion. The slowest device connected to a controller sets the bandwidth of the interface. For SuperSpeed USB (defined since USB 3.0), connected devices can request service from host. Because there are two separate controllers in each USB 3.0 host, USB 3.0 devices will transmit and receive at USB 3.0 data rates regardless of USB 2.0 or earlier devices connected to that host.

 

USB 2.0 - As of 2004[update], the actual throughput of USB 2.0 high bandwidth attained with a hard drive tested on a Mac was about 18 MiB/s, 30% of the maximum theoretical bulk data transfer rate of 60 MiB/s (480 Mbit/s). On Windows, the highest speed observed was 33 MiB/s, or 55% of the theoretical max. The drive could reach 58 MiB/s on Firewire, so the drive's speed was not a limiting factor.[56]

 

According to a USB-IF chairman, "at least 10 to 15 percent of the stated peak 60 MB/s (480 Mbit/s) of Hi-Speed USB goes to overhead — the communication protocol between the card and the peripheral. Overhead is a component of all connectivity standards.

 

USB 3.0 - A new feature is the "SuperSpeed" bus, which provides a fourth transfer mode at 5.0 Gbit/s. The raw throughput is 4 Gbit/s, and the specification considers it reasonable to achieve 3.2 Gbit/s (0.4 GB/s or 400 MB/s), or more, after protocol overhead.[70]

 

When operating in SuperSpeed mode, full-duplex signaling occurs over two differential pairs separate from the non-SuperSpeed differential pair. This results in USB 3.0 cables containing two wires for power and ground, two wires for non-SuperSpeed data, and four wires for SuperSpeed data, and a shield that was not required in previous specifications.

 

I don't want to sink a lot of money into a DAC for my SOTA music server that will obsolete in 3 years. An with all these wonderful Ultra Rez audio recordings becoming available -how long before the 24/192 barrier is broken? Do I hear a 64/384 coming??

 

System now: i5 Quad Core>Foobar>Sox>RME Fireface 800 (Firewire 800 - 1394b)>Synergistic Absolute Ref SPDIF cable>APL tubed DAC (6 AKM processors per channel, ECC99 output, Lundahl Transformer coupled, Super clock, 6 separate discrete powers supplies, special designed SOTA SPDIF receiver board - 0 jitter).

 

Thanks!

 

 

 

[The Computer Audiophile]

Hi logicsound - I certainly don't want to hinder discussion on USB 3.0 or stop a legitimate post so please forgive me if I've misjudged your comments and intentions.

 

I must say I am suspicious of this post. You joined the site and quickly posted something that looks like marketing material. It appear that you know of a USB 3.0 DAC and are looking for someone else to take the bait ("If anyone hears of one - even in development - please post") and leave a comment about it.

 

I've looked into USB 3.0 for audio and it appears to offer no benefits. The bandwidth needed for the highest sample rates is already available in USB 2.0 (both theoretically and in real products available now).

 

Hopefully there are benefits of USB 3.0 for audio and I just haven't seen them yet. Maybe I need to do more research.

 

 

 

[gkoones]

The advantage of USB 3 will be in the derivative products. It will spur the development of a new generation of high function interface chips. I’ve always wondered why there is any jitter at all in either USB or FireWire. Both have transmission speeds that far outstrip the rather modest need of audio. You can simply build a couple of buffer on the DAC side, send the bits to the buffer, and then clock them out to DAC with zero jitter.

 

[Lars]

Chris,

 

Logicsound posted something similar at AA. The response was not positive for the poster. I guess he is looking for a more favorable reaction at this site.

 

[logicsound]

Lars - I was the poster there -and the negative reaction, as expected, was from those with a vested financial interest in the status quo. Not all the reaction was negative.

 

Many years ago I had a debate there with a respected Audio Engineer about the superiority of Firewire 800 to non-aysnc USB 2.0. At the time has was marketing a line of USB DACs that used non-async USB 2.0. He was a gentlemen in the discussion - but refuted the issued regarding high jitter in USB or the need for Asynchronous communications.

 

I also made the point of the advantage of having a separate DAC from PC interface. One could be upgraded while keeping the investment in the other.

 

I moved ahead with my FireWire 800 based system.

 

In the intervening years he has produced an excellent upgrade to USB 2.0 with asynch mode - I roundly applaud him for that. It took incredible effort and design prowess. He has made USB 2.0 close to equal to Firewire 800. But we are now at the beginning of a new leapfrogging technology. As they say in StarWars - resistance is futile.

 

I post this only in the name of honest, gentlemanly, open discussion.

 

[logicsound]

Hi Chris - I love your website. No I'm not in the audio business in anyway nor associated with anyone in the business. I'm strictly a high end user, and have been for many years.

 

I am seeking a USB 3.0 DAC for my own system. I have what I believe is a SOTA system now, but would like to see if I can't improve it even further.

 

I am amazed at your not being able to see how USB 3.0 would be a game changer. The benefits are numerous and listed in my post - as to whether they will translate into better sound - that remains to be seen and will depend, like so much in audio, on implementation.

 

I am hoping to prod a few manufacturers to explore this as an option, as it is the natural tendency to stay with what they have out on the market now. After all it does cost money to develop these things. Naturally a company with a product that might be leapfrogged by a move to a new revolutionary technology might be inclined to discredit the need for such an advance, or dismiss it as an "incremental" advance.

 

After all what did everyone say about computer audio a few years ago - it'll never beat the spinning disc on sound quality (especially SACD and DVDA). I know in my many, many years of building these music systems and experimenting with many solutions, ie USB 2.0 high speed async, Firewire 400 and 800, CAT9/PCIe based interfaces and DACS what these systems are capable of. At least to my ears my current Firewire 800 music server exceeds a redbook CD and comes very close to SACD - all from 16/44 wave files. With my 32/176 archived LP files - nothing compares (except the LP itself - but I sold my $30,000 analogue set-up, after archiving to devote the funds to rest of my system- kept the vinyl though - maybe one day to re-archive at 64/352). During my archiving process, I spent many months painstakingly comparing 24/88, 24/96, 24/176, 24/192, 32/176 and 32/192 archived recordings. The winner every time were the 32/176 files - 90% to 95% of the actual LP, incredible. The difference between 16/44 and 24/96 was huge - the difference between 24/96 and 32/176 was quite large. interestingly 32/192 was very slightly inferior to 32/176. So every last LP (hundreds) were archived at the level (three - 1Tb hard drives full!). The point is these higher resolutions do make a difference. Will 64/352 be an even greater improvement? The evidence strongly suggests so. What about even higher rates? What about very complex algorithms that can upsample a 16/44 to these higher resolutions - experimenting with Wavelab 6.0 the results were better playing an up sampled/converted file versus upsampling on the fly in real time.

 

A few years ago people would laugh at the thought of 24/192 audio files - who needs that level of resolution? Isn't 24/96 enough? Where will you find such recordings? Well look at where we are today. And at the rate of technological advancement - and the appetite of those looking for SOTA music reproduction - the 24/192 barrier will be broken in the not to distant future. I know I am ready.

 

With the price of storage dropping rapidly - 1.5 T hard drives now below $100 - storage is no longer the issue (why would anyone compress their wave files now?).

 

Sincerely, I have been searching high and low for a USB 3.0 DAC or interface and have not seen anything yet. I am in the market to buy.

The PCs with USB 3.0 are already readily available - how long before it is standard on the higher level machines and USB 2.0 is phased out? Maybe available on the entry level boxes only. Look at some of the issues folks are having with their USB 2.0 DACs working with a USB 3.0 PC.

 

PS I noticed you did not list the RME Fireface 800 on your list of DAC/PC interfaces. It is the only one I know of that uses the higher throughput FireWire 1394b. Several reviewers in the UK use it in their reference system. I respectfully request you add it your list so potential buyers would be aware it exists, it really is unique (and I have tried to many to list).

 

Thanks!

 

[sjsanford]

dude, you can't come into the nerd sandbox and attribute "resistance is futile" to Star Wars!!

 

[logicsound]

sjsanford

 

You are so right my humblest apologies.

 

Star Trek: The Next Generation (1987–1994). How could I forget the Borg...

 

 

 

[steve2701]

It's my guess that by the time USB is fully implemented into real hifi (ie - high end kit and made to work to the Nth degree correctly and with every file type - jitter free with all the bells and whistles ) USB, should it still be used will be on USB24.

The PC world moves at one pace - audio at another. Audio is but an absolutely minute thought in the world of these designers. Copy Protection along with huge data rate transfer is somewhat higher on their 'to do' list.

If you have a SOTA system now - take some time, smell the coffee and enjoy the music it can make. Are you honestly expecting 'that' much of an increase in sound quality? I'm not. Diminishing returns set in a good while ago.

 

[sq225917]

Well given that theoretical 24bit signal is at the level of johnson noise what possible benefit could their be to greater mathematical precision? Genuine question, i'd love to hear an answer that supports the rhetoric with some listening test data proving that anything beyond 24bit is audible as an improvement.

 

There are already async devices using custom programmed silicon on the dac side as the receiver chips with sufficient buffers to render jitter at the interface effectively inconsequential, and some of these handle 384khz sample rate material anyway. The Young dac from M2tech already does 32bit 384khz over usb 2.0. I don't doubt the a true duplex protocol offers benefits in terms of reduction in data transfer for high speed transfer, but is there anything that shows this to be beneficial to the data rates required for even 32 bit 384khz material, or does it simply offer a broader palette of possible protocol control solution from which designers can pick and choose their weapon of choice?

 

My current digital front end matches what I hear from my £8,000 analogue front end, is there really any point in further specification chasing?

 

[The Computer Audiophile]

I don't think there are any gains to be had based on speed of USB 3.0. What do people think of the other differences in its architecture compared to USB 2.0? Could there be benefits or possible negative consequences with the new standard?

 

[logicsound]

Hi Steve2701

 

You make some very good points.

 

"It's my guess that by the time USB is fully implemented into real hifi (ie - high end kit and made to work to the Nth degree correctly and with every file type - jitter free with all the bells and whistles ) USB, should it still be used will be on USB24."

 

Well I have been using a FireWire 800 interface for approximately 5 years. RME launched the 800 in 2004 about a year after Apple made it available on their computers. The 800 nailed 1394b perfectly, yes there have been software and firmware updates, but these are free and easily loaded.

 

It is now almost a year since the launch of the first motherboard with USB 3.0, so now is the time. Nothing from RME yet.

 

"If you have a SOTA system now - take some time, smell the coffee and enjoy the music it can make. Are you honestly expecting 'that' much of an increase in sound quality? I'm not. Diminishing returns set in a good while ago."

 

This a good point - I am blown away at the detail retrieval and absolute grain free musically of the server. And I have had that for a good number of years, I would have never given up my analogue rig if the server based system wasn't that good and oh so convenient. I am up to 56 different play lists.

 

So is this a case of Audionervousa???

 

Yes probably. Deminishing returns? Very good question.

 

I have had an ongoing policy with my system - if a new component doesn't make it sound better off to Audiogon it goes (and I have few hundred transactions there - lots and lots of cables).

 

But then I think back to when I started building my music servers(I have three now, one in my office, one in the media room and the SOTA in the stereo room), what if I never tried for something better. I'd still be hunting down discs to play in my transport - or listening to an Ipod! Not that there is anything wrong with that - I have a few of those for the road as well.

 

So as an intrepid pioneer on the cutting edge of digital audio I push forward.

 

Id rather be hunting for the Higgs, but couldn't afford a $10 billion dollar LHC.

 

[logicsound]

Hi sq225917

 

I hear what you're saying. But some times as I have pushed forward the sound gets noticeably better. And it is funny how what seems like a small improvement with continued listening blossoms into some deeper level of truth - I am to the point now where I judge system changes in how it draws me in, involves me in the music. Some times it seems like magic -or trance invoking - quite powerful - and deeply relaxing. I believe this is the root of why we are audiophiles - there is a biochemical reaction going on in our brains. In a way we become addicted to it - the complete sense of relaxation and peace. Like TM with out the mantras. Have you read "This is your Brian on Music", the academics are starting to document this.

 

This "small" improvements make a pretty big change in effect. Does it bore you, entertain you, or really draw you in, involve you emotionally. I was listening to some Eric Clapton the other day, Blindfaith, not very well recorded we know. But the music kinda lit up, Winwood's voice became holographic, Clapton's guitar magical. All from a 40 year old recording. Amazing.

 

Maybe you are right and USB 3.0 is no better then USB 2.0 optimized, or a 64/352 file is no better then a 32/176 or 32/192.

 

My experience in archiving my LPs, showed me a large improvement came in moving form 24/96to 32/176 - so I have to wonder.

 

I heard recently of some new algorithms that can restore some of the time domain/phase distortions created in the digitalization process, but the "restored" file require something like 1Gb/sec data streaming. Maybe this works, it's supposed to do amazing things to ambient signal retrieval, maybe it's bogus. Time will tell.

 

Maybe we wind up with holograms in our living room. Check out Miku - big hit in Japan. http://www.youtube.com/watch?v=DTXO7KGHtjI

 

You mentioned English Pounds in your post - I'm pleased to say I am the first in the US who has Tellurium Q Ultra Black cables - they are incredible! Replaced my SR Apexs with no regrets - give them a listen if you have time - very reasonably priced. Unfortunately, not sold in the US yet. Read a review in a UK audio mag and bought a pair -love'em. They've received rave review in the UK

 

Cheers

 

[logicsound]

Hi Chris

 

Here is some research at least on the possible improvements using higher sampling rates. This is from a whitepaper on the DXD system. A link is provided to the full paper.

 

I think you posted something about this back in 2009. DXD was way too expensive and probably ahead of it's time. But USB 3.0 or possibly USB 2.0 - although I doubt it, could make it a low cost reality.

 

"DXD is acknowledged by Philips and Sony as a

high sample rate and multi-bit processing format for

recording and editing for SACD productions. DXD is

defined as a 24-bit signal sampled at 352.8kHz."

 

"Two factors define the pulse response — the roll-off

frequency of the sampling filter (anti-alias filter) and

the slope of the filter roll-off. A high roll-off frequency

gives a high amplitude pulse because of more high

frequency content being present. A slow roll-off slope

will produce less pre and post ringing of the pulse and

thus a more precise time point for the pulse.

Due to its relaxed filter slope and high bandwidth

DSD has a perfect pulse transparency. The results are

different for the different PCM rates. These have a

higher pulse when the sample-frequency increases,

but the steep filters needed to comply to Nyquist (i.e.

having full attenuation around the half sample

frequency) will have the effect of pre and post ringing.

At the higher rates a more relaxed approach can be

made towards the filter steepness since the risk of

having audio contents folded down is very small as

the efficient amplitude of the audio is very low at rates

beyond 50kHz, for example."

 

The graphs show superiority in many regards:

 

Much faster and accurate Pulse Response then 24/192

 

Better frequency Response

 

Lower Noise Floor.

 

The lower level of ringing on the Pulse Response as well as the more relaxed filter steepness are most interesting to me. This may help to address some of the phase/time domain distortion from the digital playback process.

 

www.lindberg.no/english/collection/004.pdf

 

http://www.computeraudiophile.com/content/DXD-DACs-horizon

 

[Audio_ELF]

Star Trek: The Next Generation (1987–1994). How could I forget the Borg...

And before that the Cybermen created by Kit Peddler and Gerry Davis in 1966 for Dr Who.

 

Eloise

 

PS. On the original topic... Buy a DAC now an listen to music and be happy. As others have said USB3 offers nothing new for the audio lover.

 

[logicsound]

Chris,

 

I was digging through the posts on that thread about DXD. This was an interesting comment from Bruce Brown at Puget Sound Studios. This was in response to one of your questions.

 

They chose the DXD version to master - that was obviously more work - I'm sure they did that because it sounded better.

 

Did anyone in Seattle get to hear those Master recordings?

 

 

"Yes, we were in Japan recording the Yamamoto Trio. This was recorded at 4 different resolutions. The studio recorded at 24/192 on a Pro Tools rig and on 1/4" tape. We recorded from the SSL 9k mixing board into DSD and DXD. The DXD version was used for the production CD. I will have to say a surround feed was also captured at DSD and DXD for possible future release.

We then took the files back to our studio and listened carefully to each one and chose the DXD version to master.

 

Regards,

__________________

 

Bruce A. Brown

Puget Sound Studios

Seattle, Washington"

 

How cool would it be to be able to purchase those DXD recordings and play!

 

 

[logicsound]

Hi Eloise

"PS. On the original topic... Buy a DAC now an listen to music and be happy. As others have said USB3 offers nothing new for the audio lover."

 

I will be the first to admit, this cutting edge stuff is not for everyone. But some want to push the envelope. We can not be so sure USB 3.0 "offers nothing new for the audio lover", until we hear it.

 

But I'm glad you are completely satisfied with your system - I'm a bit jealous!

 

[glt]

For "improvement" you should look at bulk transfer mode solutions. USB2 already gives you ample bandwidth for hires audio, so that in most cases, guaranteed bandwidth afforded by the asynch protocol is no longer the bottleneck. Bulk transfer gives you guaranteed delivery because the endpoint acknowledges the receipt of the packets (after doing the CRC error checking)

 

[losingmyreligion]

 

"I don't think there are any gains to be had based on speed of USB 3.0."

 

I would strongly agree, albeit based on my experience with Firewire.

 

The best of class Firewire DACs all use FW400 - the Weiss devices, including DAC202, the Prism Orpheus, and the Metric Halo ULN-8/LIO-8 (and the similar Amarra Model 4 / Sonic Studio models).

 

IOW, even firewire 800 bandwidth is NOT needed for SOTA performance.

 

Note: Metric Halo found FW 400 to be sufficient for 8 channels of SOTA ADC/DAC performance.

 

 

clay

 

[losingmyreligion]

 

"USB2 already gives you ample bandwidth for hires audio, so that in most cases, guaranteed bandwidth afforded by the asynch protocol is no longer the bottleneck."

 

Async protocol is a bit of a misnomer, as it doesn't clearly articulate the most important aspect of it's use - which is to allow the master clock to be located in the DAC. Non Async methods require use of a clock signal (as Master) in the source , which the clock in the DAC needs to be kept in sync with. Methods for keeping the DAC's (slave) clock in sync with the source are not as jitter-free as using a single master clock in the DAC.

 

Perhaps you've heard the old saw:

"A man with only one clock always knows what time it is, a man with two clocks is never sure."

 

clay

 

 

[gkoones]

One effect of USB 3 is it might make marginalize FireWire to such an extent that it will for all intensive purposes disappear. The computer industry has a way on converging on single interfaces. With USB 3 as fast as the latest versions of FireWire, you might find FireWire disappearing from both Apple and the high end Intel motherboards. Once native support disappears, peripherals, like DACs will follow.

 

[losingmyreligion]

"One effect of USB 3 is it might make marginalize FireWire...."

 

Don't have an opinion on what PC makers might do - and frankly don't give a hoot - but there'd be no reason for Apple to disenfranchise their Firewire user community.

 

To claim USB 3.0 support, all they need to it take one of the multiple USB 2.0 ports and replace it with 3.0. They already support both Firewire and USB.

 

Since USB 3.0 is mostly a solution in search of a problem (i.e. who really needs it), it will be many years before USB 2.0 devices are supplanted by 3.0.

 

Given the extra 'cost' of supporting 3.0, there's no point in replacing all of their existing ports with USB 3.0 (contrary to your suggestion "The computer industry has a way on converging on single interfaces")

 

Moreover, Apple is NOT a supporter of USB 3.0, having put their weight behind LightPeak.

 

Why would they want to make their loyal Firewire users move to USB 3.0 when they can maintain their loyalty while incubating LightPeak?

 

Anyone in the market for a USB 3.0 mouse?

 

;0

 

 

 

[gkoones]

No current generation system has a USB 1.1 only port, they have USB 2 ports that are backwards compatible with USB 1 and 1.1.. Within the next two years of so, native support will be all be USB 3 , backwards compatible with previous versions. The extra cost, zero. As for LightPeak, stop listening to the Intel press releases. They pushed WiMax which went and is going nowhere, they pushed NGIO with was transformed into the marginalized Infiniband and they would produce 64 bit x86 pushing Itanium until AMD ate not only their lunch but their breakfast and diner for years.. LightPeak is only Intel’s way to get a patent royalty interface to avoid being overrun by 10 GB Ethernet. Computer interfaces live by the motto, marketshare is everything, and just like “The Highlander”, in the end there can be only one. Ignore Jobs, if USB 3 becomes ubiquitous Apple will support it in an instant.

 

 

 

[The Computer Audiophile]

"USB 3 Extra Cost = 0"

 

 

gkoones - The cost to implement a USB interface would be substantial. You can't simply drop USB 3 into a computer where the USB 2 chip was and expect it to work. Major design and testing has to be done. Plus I'm guessing licensing for USB 3 is more than 2. Just a guess though.

 

Please take this in the spirit in which it's intended. Your tone, i.e " stop listening to the Intel press releases" is not inviting of others to leave a comment here and comes off as quite arrogant. Based on your comments it's clear you don't know it all so I recommend not talking like you do.

 

[losingmyreligion]

 

"Ignore Jobs, if USB 3 becomes ubiquitous Apple will support it in an instant."

 

So what if they support USB 3.0?

 

It will likely be many years before USB 3.0 becomes ubiquitous, if ever it does.

 

 

You're still missing a most important point. Apple is supporting USB now - to the tune of 4 or so USB ports - yet they still retain a Firewire port on the majority of their computer models, contrary to your belief that the computer industry wants only one port.

 

Apple have no reason to insure that their Firewire customers move to USB 3.0. They can maintain that loyal customer base (you know, the ones who bitched when Apple started to remove Firewire ports a couple of years back) by simply keeping a Firewire port on their professional machines.

 

clay