Is usb reclocking necessary?

usb reclocking or cleansing (there are various devices by innous, w4s, ifi) often helps computer streamed digital outputs

Interesting question. I have a QB9 Twenty as well. I am feeding it with an Aurender N100. Since the QB9 must depacketize and time the bits I wouldn’t think of that as an option, so I wouldn’t think it would. But absolutely every time I have thought something would not matter it has. Since there is a product to do it, someone thought so. I bet it does. Well, if you get it, let is know.

I find it is very helpful & useful, so much so that I daisy-chained two reclockers and enjoy much better clarity and dynamics.

I had a DAC over 10 years ago that did not have a synchronous usb input.  The DAC was great with S/PDIF, but with usb the soundstage completely collapsed.  On Orchestral recordings it sounded as if the bass drum and the tuba were side by side with the Conductor.  I then bought one of those cheap reclocker devices by Musical Fidelity.  It came in ugly casework, had no independent power source, and stopped working after a week.  During that week, however, it made the usb almost equal to the other inputs.
  Todays DACs come with some type of reclocker.  The question then becomes how much additional sonic benefit can be derived from an additional reclocker.  Surely the numbers would would better on a graph, but any audible improvement?  I noted with interest that with dCS, more than one respected reviewer thought there was no audible benefit to the separate reclocker, which cost around $10K

ghdprentice I just got my Ayre DAC last week which was used when I got it. Should the sampling rate be displayed on the front panel? Mine just shows a green dot on standby when there’s no streamer playing and then a blue dot when it is playing. No sampling rate.

ghdprentice never mind I found the switches in the back.

@hysteve


Great! You will really love the DAC. I have actually had mine since new more than 10 years ago, then upgraded it about a year ago to the twenty version. It really is an excellent DAC by today’s standards.

Ayre knows how to engineer the USB interface properly - they were one of the first, if not *the* first to implement an asynchronous USB interface.

I owned a QB-9 DSD for a few years and never felt there was a need for a USB reclocker / filter / etc.

Very much system-dependent.
Don't buy anything you can't return.

No

With Asynchronous DAC like Ayre QB9 data is not delivered in real time*. Asynchronous means that USB clock and DAC’s D/A conversion clock are independent (asynchronous). Reclocking Asynchronous USB doesn’t make any sense. On the other hand "Reclocker" might have built-in filters on data and power lines that reduce injection of digital noise into DAC (always good thing). I would search for USB filter (but such filter might be already built into DAC).

*Computer sends data in "Frames". Each frame contains multiple music samples. These frames come at slower rate - likely 1kHz.
DAC places them in the data buffer signaling back buffer’s under or overflow. Upon this signal computer adjusts size of next frame.
That way clocks are independent, but data is not lost.

I think the Ayre's USB interface is powered by the DAC power supply so it doesn't draw anything from the computer. A filter for the power lines would be useless.

When DAC is self powered, then USB power is not necessary but GND connection is still required since single ended (GND referenced) signaling is used at the start.  It might be possible to lift the GND after music started playing as long as data common mode stays within input range.

That depends. Re-clocking reduces jitter. If you have a sufficiently good DAC ($$$ is not always good or sophisticated), the jitter is already handled - maybe better than the re-clocker. I did see some test data that indicates that many reclockers are not all that good.

However, jitter makes a big difference. Since I am beginning the process of DAC design, i started by adding USB interfaces to two old, but excellent in the day, DACs that were S/P DIF only (one step ahead of smoke signals).

Holy smoke signals batman! What an improvement. OK, OK, low bar, yea, but it goes to show the fundamental issue we’re dealing with.


Now if you reclocker is <<< than your mega-bucks DAC, it ought to, uh, worsen jitter.
Its neither magic nor rocket science. Its jitter, which is the X-axis in the Cartesian system that translates a digital code to an analog waveform.

If you have a 10 MHz hook up on your dac it for sure makes it better in every way it fleshes out more in the recordings.

I have the SOtM SMS-200 Ultra Neo as streamer and the Wyred4Sound USB reclocker made the sound worse.

Before trying USB reclocking, I would strongly advice you to get a good DDC (like the Audio-GD DI-20HE), before the DAC, mostly if it has I2S input, no to reclock the USB signal, but to convert it to an easier digital signal for the DAC to shine at it's Best.

Another good improvement is the Uptone Etherregen switch.

Also using a 10 Mhz master clock with everything you can in the digital chain will help considerably. Both, the DI-20HE and Uptone Etherregen accept external master clocking and improve with it.

Also antivibration and AC treatment help A LOT.

You all have obviously been at this for awhile. I’ve been out of it for 40 years and just getting back into it. I don’t know what a 10 MHz hookup is! I did add a Furman power conditioner/surge protector and it made a slight sonic improvement. I have a carpeted floor and putting the floor standing speakers (Volti Razz) on thick pavers improved the bass too. A good step might be to add a good turntable to audibly judge the digital reproduction against. That may tell me where to stop tweaking. Thank you all for your input!!

You know, looking at your question again. The answer is clearly no, the Ayre is an excellent DAC so it is not necessary. You will likely enjoy a good turntable. While my Ayre is a good DAC, it does not approach a good analog end. There are so many great turntables out there… but don’t forget a great Phonostage is required to get the most out of a good turntable. I am just listening to an analog recording and marveling at its wonderful sound. 

You don't get clock anomalies with analogue.
All fixes for clock error and dither are cludges.

@kijanki The QB-9 USB interface is galvanically isolated from the DAC section so ground pollution shouldn't be a concern.
Seriously, Ayre put a lot of thought into the implementation.
***
Yeah, you don't get clock anomalies with analog - but you *do* get measurable wow and flutter and surface noise with a turntable.

I will point out that the clock anomalies ARE analog :-)
.. and have direct analog implications.
I will also add something i ought to have said earlier but neglected to:  proper clocking inside the DAC (either between the USB interface and the internal oversampling or as the actual system clock itself) is vastly better than an external box.  An external box can only reduce the incoming jitter.  Keep in mind that, in an idea world,that jitter ought not matter since the DAC syncs on that, and generally either terminates or enacts a PLL to reduce jitter and then  typically clocks things in an out of whatever register arrangement exists.  But clearly, it does matter.
Since the only thing that matters is the timing coming into/out of (they better match!) your DAC chip or resistors, the latest possible point to execute a proper clock is the best.  his makes any box you can plug in less than ideal. Unclear what the outcome is if it is better than source but worse than internal.
That would be an interesting experiential some day.

No. Only unclocked USB signals need to be clocked. With modern clocks reclocking is unnecessary. 

If you want to fidget with your system get a turntable.

The innous reclocker is a good device and will make any dac sound better

We have a huge selection of dacs and the Phoenix did make an noticable improvement

We now sell servers which include seperate sound cards and clocks
So we don’t need any such devices as it is built in

Dave and troy
Audio intellect nj
Importers 432evo music servers

I would urge you to find a dealer that will allow you to demo a Phoenix USB in your current system to see if it improves sound quality enough to justify the cost. In my system, the Phoenix improved the realism and naturalness of the music supplied by my Innuos Zen Mk3 and processed by my PS Audio Directstream DAC.

I liked that the Phoenix was designed to work perfectly with my Innuos server and included a clock, a high-quality power supply, and a USB regenerator in the same case rather than expecting me to cobble together several external boxes and power supplies. This is basically the same approach as Innuos took in designing the USB path for their top-of-the-line Statement server. The fact that you already own a Zenith server makes the Phoenix a logical upgrade path for your system. But you really should demo it first to make sure that the sonic improvements you hear are worth the cost.

@mijostyn says:

No. Only unclocked USB signals need to be clocked. With modern clocks reclocking is unnecessary.

Well, that appears true on the surface. And most people don't specify enough configuration data to rally know. But let me be very clear: with systems running with the source as slave and the DAC as master (clocking), and with stuff that was considered well-clocked when it was new, adding a USB interface with isolation and re clocking has made a huge difference several times.

Note that my data point is NOT a box in the middle, which brings its own can of worms, but a replacement of the coaxial SPDIF provided originally with a custom PCB with independently powered (line powered) USB; full ground, signal and power isolation; clean power to the processing stage, and tight clocking beginning with a read buffer --> then spit out to the DAC.  Yes I'm being a little vague.

So while your point is well taken it comes down to "how well is the internal clocking/timing implemented?", "how dependent is it on source timing?" and "how good is the magic box being added".

I tend to agree that i would NOT just add a magic box.

@yage Thanks.  In that case I cannot see any reason even for filtering.  

Hi guys, old thread but hoping I could revive it to get some help. Is a USB re-clocker going into a DAC with a asynchronous USB redundant? From what I've read in an asynchronous setup, the DAC will re-clock when it pulls the info from the server/streamer. So it would be re-clocking out of the streamer/usb re-clocker right into another re-clocker? Looking at getting a DAC that has an asynchronous USB and  and Innuos streamer. Would I really need the Innuos with a re-clocker if my DAC has asynchronous USB or could I potentially save some money and just get an Innuos mini streamer?

@bg3584

While you are correct that the streamer is slaved to the Dac under asynchronous USB, the actual connection needs reclocking since USB as a two way port has a separate algorithm rather than embedding the clock signal in the data stream. Hence the utility of the reclocker.

I used a pretty good one (Mutec MC-3+USB) into a $6k DAC-Preamp on the Stereophile "A" list. There was a positive difference. Then, I got a newer DAC-preamp ($4k), and I found that the reclocker added harshness to the sound.

My conclusion: this is just as system-specific as power conditioners and maybe even cables. Try to be objective when you evaluate a reclocker in your own system, and don’t buy anything that can’t be returned for full credit. And finally, don’t listen to technical arguments for and against, as many of them are just BS. Listen to the sound with your own ears, in your own system, and if at all possible, make blind comparisons.

I have an Innuos Zenith mk 3 with the reclocker. It only made a slight difference in my system. I think the key is how good your DAC’s USB implementation is. I run a Terminator Plus which is known to have a great USB input.  We all tend to look for sound upgrades to our systems that don't require large expenditures.  Perhaps a better strategy is to bank that cash. and invest in better speakers that truly have a large impact on SQ.

I see this discussion came back to life after over 2 years. As the OP, I think I dropped the ball by not following up after trying and buying a Innuos Phoenix USB reclocker for my Zenith MK3. I found an outlet in Nashville that demos Innuos reclockers for the price of shipping- very reasonable. There was no question, after playing less than a track, that I had to have one. It made a huge SQ difference in my system. There is much more clarity. I’m 1 piece short of a Innuos Statement equivalent. Haven’t convinced myself yet to get the Innuos switch.

OP,

 

Thanks for the follow up. Good to know. 

Another way of skinning this cat is to add a 10m clock to the dac where the dac’s got the necessary BNC input. Since most dacs don’t contain $7000+ clocks that way you skin two cats in one fell swoop: better conversion clocking on the dac and better USB clocking on the slaved streamer. Not what InnuOS wants you to do but highly effective; and while you are at it: the 10m clock can equally be used on the ethernet switch, whether Etherregen or other (again provided it has the necessary BNC input) killing multiple birds with one clock (ooopppss….)

Now then: some designers insist external clocks don’t benefit sound quality (Ed Meitner et al) Numerous equally reputable designers, the likes of MSB, DCS, Esoteric et al beg to disagree with that view as does my listening experience.