Asynchronous USB or USB converter to spdif?

[jaxwired]

Any comments much appreciated. Would like to know, if I have an asynchronous USB DAC, will a good USB to SPDIF converter still reap rewards? What I mean is, is it any

benefit to convert to spdif prior to the DAC so I can use the DACS spdif input rather than the USB?

[pfarthing]

Hard to generalise. It largely depends on the DAC

[BobP63]

Hard to generalise. It largely depends on the DAC

 

And the convertor...

[Lappy27]

I have a NAD M51 which is asynchronous and adding an Audiophilleo2 + PurePower to it make a really HUGE step up in performance. Absolutely nothing subtle at all.

[drez]

Hard to generalise. It largely depends on the DAC

 

^this

[christopher3393]

Entirely depends on the dac.

[tranz]

Any comments much appreciated. Would like to know, if I have an asynchronous USB DAC, will a good USB to SPDIF converter still reap rewards? What I mean is, is it any

benefit to convert to spdif prior to the DAC so I can use the DACS spdif input rather than the USB?

 

From my limited experience I have noticed with the Berkeley Alpha USB converter that no matter which DAC I tested, including MSB, Ayre, McIntosh, etc., using the external Berkeley converter, and using the XLR (AES/EBU) into the DAC beat the internal USB connections of all the DACs. I think that USB is inherently just so noisy in the EMI/RFI area that keeping it physically removed from the sensitive DAC, clock and analog sections makes a big difference.

 

In addition I use an IFI USB Power to clean the USB power and cut the USB ground before sending it to the USB-SPDIF converter. All this is bit perfect by the way but just helps in removing common mode noise.

 

Cheers

[wkhanna]

......... clock(ing).......makes a big difference.........

 

 

+1

 

Any DAC can only play what it is fed.

[SoNic67]

+1

Any DAC can only play what it is fed.

Including the jitter...

GIGO

[tboooe]

I agree with tranz. I just wish there was a way to do DSD over SPDIF as I would really like to experiment with PCM2DSD and compare DSD files versus high res FLAC.

[Jud]

+1

Any DAC can only play what it is fed.

Including the jitter...

GIGO

 

Re jitter, depends on the DAC input and whether the input permits reclocking in the DAC. Wrt the subject of the thread, if the input isn't async , then use of an external async converter will help ensure one doesn't get "garbage in."

[tranz]

I agree with tranz. I just wish there was a way to do DSD over SPDIF as I would really like to experiment with PCM2DSD and compare DSD files versus high res FLAC.

 

Hi tboooe,

 

You can do that using DoP (DSD over PCM) in Audivarna for example. The data stream in my setup went through an IFI USB Power and the Berkeley USB Alpha before hitting the DAC through XLR (AES/EBU). However, since most USB-SPDIF converters max out at 192Khz you are limited to the 64x DSD, but you can certainly try it out.

 

Cheers.

[tboooe]

Thanks tranz...I will have to try it out though it is not optimum.

[jaxwired]

Thanks everyone! Wish there was a more definitive answer. Gonna start another thread outlining my real underlying question. Thanks again!

[Lappy27]

Thanks everyone! Wish there was a more definitive answer. Gonna start another thread outlining my real underlying question. Thanks again!

 

jaxwired,

 

I don't remember any feedbacks from users who did the comparaison, that said that a good top of the line USB to SPDIF converter does not add performance to a USB dac.

 

In fact, I challenge anybody to prove the opposite assuming we are talking of converters that a normal human beeing can afford.

 

i did the comparaison and I will never can be able to go back listening in direct USB connection after adding the AP2 + PP. And this opinion is shared by at least five others people (on five) who listened to my set up in a recent mini-meet.

 

So, to answer your underlying question. A DEFINITE YES!

[SoNic67]

Any comments much appreciated. Would like to know, if I have an asynchronous USB DAC, will a good USB to SPDIF converter still reap rewards? What I mean is, is it any

 

Anything will be better than an USB async. Async is good for mouse, keyboard, printers... stuff that can wait for the USB master in the PC. DAC's are real-time, cannot afford that luxury.

[Jud]

Any comments much appreciated. Would like to know, if I have an asynchronous USB DAC, will a good USB to SPDIF converter still reap rewards? What I mean is, is it any

 

Anything will be better than an USB async. Async is good for mouse, keyboard, printers... stuff that can wait for the USB master in the PC. DAC's are real-time, cannot afford that luxury.

 

- The system for music playback that includes the DAC has never been "real time," and in some respects, the less "real time" the better.

 

The respect in which pretty well all DACs are not real time is that the bitstream is buffered before being clocked out of the buffer into the conversion process. The respect in which a playback system that is less real time can be better is that software players that enable playback from RAM can avoid computer activity deleterious to sound quality occurring at the same time as conversion in the DAC.

 

- To the OP: Of course the answer is "it depends." Having the async interface in the DAC gets the clock closer to the conversion process, a good thing to lower jitter. OTOH, a separate box can potentially keep electrical interference out of the DAC itself to a greater degree.

 

Essentially, here as elsewhere, best specific implementation wins over any general rule about same/separate box.

[Allan F]

Essentially, here as elsewhere, best specific implementation wins over any general rule about same/separate box.

 

There has been a major improvement in implementation of asynchronous USB in the last year or two and I doubt that the better recent USB DACs would benefit from a USB to SPDIF converter.

[SoNic67]

- The system for music playback that includes the DAC has never been "real time," and in some respects, the less "real time" the better.

External DAC (USB, SPDIF) is always real time, unless you have buffer memory on DAC itself. Data will come with the rate that sync USB (push method) dictates, and with the interruptions for all other devices on that USB chain.

True though, async USB (pull method) is better, it will request that data based on DAC needs, but it still depends on USB master to comply with the requests. If master is 'busy' with other devices, DAC will loose samples.

Best DAC's will have a generous RAM buffer on board.

[sjoc2000]

Any comments much appreciated. Would like to know, if I have an asynchronous USB DAC, will a good USB to SPDIF converter still reap rewards? What I mean is, is it any

benefit to convert to spdif prior to the DAC so I can use the DACS spdif input rather than the USB?

 

Hello Jaxwired;

 

Not feeling very technical tonight. The generalization that asynch USB can be less than stunning is just silly, but completly dependent on the dac.

 

The Mytek will likely knock your socks off (@ $1595-1695), and perorms flawlessly with DSD as well - no converter required. At least that is my experience, as well as that of many others here.

 

You only have one person to satisfy, and that is yourself. Give one a trial, if you have the inclination and time, your likely to be very pleased...

 

 

Jim

[Jud]

- The system for music playback that includes the DAC has never been "real time," and in some respects, the less "real time" the better.

External DAC (USB, SPDIF) is always real time, unless you have buffer memory on DAC itself. Data will come with the rate that sync USB (push method) dictates, and with the interruptions for all other devices on that USB chain.

True though, async USB (pull method) is better, it will request that data based on DAC needs, but it still depends on USB master to comply with the requests. If master is 'busy' with other devices, DAC will loose samples.

Best DAC's will have a generous RAM buffer on board.

 

Neither of the async USB DACs I've owned has ever lost a single sample , other than with a defective USB cable that I quickly replaced and no more problem. One was $450, the other not a lot more. I also had a USB/SPDIF converter (async) for just over $150 that never lost a single sample either.

 

Amazing how inexpensive "the best DACs" with those RAM buffers are these days, eh?

[SoNic67]

If you read my post you'll see that async doesn't need buffers. It just requires that your PC doesn't have something else connected on that USB hub (like an external HDD).

[Lappy27]

There has been a major improvement in implementation of asynchronous USB in the last year or two and I doubt that the better recent USB DACs would benefit from a USB to SPDIF converter.

 

Example with real life experimentation?

[Jud]

If you read my post you'll see that async doesn't need buffers. It just requires that your PC doesn't have something else connected on that USB hub (like an external HDD).

 

Nevertheless, async has them (buffers). And there have been many, many posts in the forums here from people who have other equipment connected on the same USB hub or port (look in the system information for a MacBook or MacBook Pro and odds are you, like me, will have some other device sharing a USB port with your DAC) asking whether they would get better sound if they put the DAC on a port by itself. I presume by "better sound" they don't mean constant "ticks" from dropping bits (no one's complained of that, and as I mentioned, I've never experienced any such dropouts with three different inexpensive pieces of async USB equipment over a period of a few years), but rather sound quality in general.

[phusis]

Any comments much appreciated. Would like to know, if I have an asynchronous USB DAC, will a good USB to SPDIF converter still reap rewards? What I mean is, is it any

benefit to convert to spdif prior to the DAC so I can use the DACS spdif input rather than the USB?

 

With my NuForce DAC-9, which was previously fed by an RME 9632 soundcard via AES/EBU(which I preferred over USB), the Audiophilleo2 w/Purepower via BNC-direct made a world of difference for the better. In three other setups, with much more expensive DAC's, friends have reported no less subtle differences in favor of the use of AP2 w/purepower.

 

The debate over whether to go USB-native async or via USB to S/PDIF converters has sometimes centered on the more theory-heavy "what ought to be the desired path"(i.e.: USB-native async) than what might in-effect have led to the more desirable sonic outcome via USB to S/PDIF converters. Adding another component of the kind, being relatively inexpensive, is a no brainer in my view when the sonic upgrade is of this magnitude and beating what a similarly priced or more expensive stand-alone DAC can offer via its native USB async input.

 

Of course, these are my impressions with named product; many others (and DAC-combinations) are untested by me.. Not least: your self-formed impressions via your own setup are mandatory, it goes (almost) without saying