Why is everyone using USB/XMOS. Why not PCIE SPDIF Out?

[BDWoody]

And yes - driving the clocks LT1963 regulator with a battery brings a slightly better sound. Compared with an average spdif output from a regular CD player to a dac, this option is often better sounding

Uh huh...

 

[earlevel]

Best I can tell is this is some box to convert USB to PCM coax?
Why not just get a half decent DAC?

I think it's USB to S/PDIF?

 

[Tangband]

Uh huh...

I was very sceptical myself if different USB bridges could make an audible difference. Heck, I even thought that a Yamaha wxc50 was the ” endgame” in streamers and the difference people heard with better gear was all in their imagination. I was wrong.

Try it for yourself.

 

[earlevel]

I was very sceptical myself if different USB bridges could make an audible difference. Heck, I even thought that a Yamaha wxc50 was the ” endgame” in streamers and the difference people heard with better gear was all in their imagination. I was wrong.

Try it for yourself.

Setting aside the possibility of some problems being fixed in some cases (whether it be ground loops, dropouts, whatever)...

Are you suggesting that such a device (again, this appears to be a USB to S/PDIF converter) will improve sound in the general case? Or are you saying, "if you are experiencing problems, this will likely help"?

If you are talking about general improvement, I'd wonder how Amir's tests with USB DACs don't reveal these performance issues that need to be fixed.

 

[DWPress]

I was curious about the signal quality of USB bridges too as I use them to convert USB audio to SPDIF to feed a miniDSP 4x10 a digital signal to bypass the A/D stage of it. Amir recently tested a cheap FX Audio DAC-SQ3 feeding a Topping DX3-Pro and compared it against directly feeding it from his AP - no difference except maybe removing a couple power supply spikes from the AP below audible threshold on the FFT.

 

[Tangband]

I was curious about the signal quality of USB bridges too as I use them to convert USB audio to SPDIF to feed a miniDSP 4x10 a digital signal to bypass the A/D stage of it. Amir recently tested a cheap FX Audio DAC-SQ3 feeding a Topping DX3-Pro and compared it against directly feeding it from his AP - no difference except maybe removing a couple power supply spikes from the AP below audible threshold on the FFT.

As I wrote earlier: Using XMOS ( as they did in FX audio and all Topping dacs ) seems to bee a good and cheap way to bring asyncronuos conversion and put away the 8 kHz USB packet noise, plus gaining 24 bit dithered digital volume regulation in some cases.

 

[DWPress]

The digital output of these devices is a pass-through so no digital volume control unless you use the analog outputs.

 

[VintageFlanker]

I was curious about the signal quality of USB bridges too as I use them to convert USB audio to SPDIF

This one I just tested does not degrade performance :

PHIREE U2S 2019 & Douk Audio U2 Review and Measurements (Digital USB to S/PDIF Interfaces)

PHIREE U2S 2019 & Douk Audio U2 Review and Measurements (Digital USB to S/PDIF Interfaces) Update March 2022: Added comparison with the Douk Audio U2. Here is a quick review of the PHIREE U2S 2019 digital interface. This is basically some USB to S/PDIF converter that allows you to get USB...

www.audiosciencereview.com

 

[Tangband]

The digital output of these devices is a pass-through so no digital volume control unless you use the analog outputs.

Thats a pity .

 

[Tangband]

This one I just tested does not degrade performance :

PHIREE U2S 2019 & Douk Audio U2 Review and Measurements (Digital USB to S/PDIF Interfaces)

PHIREE U2S 2019 & Douk Audio U2 Review and Measurements (Digital USB to S/PDIF Interfaces) Update March 2022: Added comparison with the Douk Audio U2. Here is a quick review of the PHIREE U2S 2019 digital interface. This is basically some USB to S/PDIF converter that allows you to get USB...

www.audiosciencereview.com

Interesting
My Douk U2 is also good sounding.

 

[julian_hughes]

I have been "out of the game" for a while. When I was last paying attention, around 2011-2012, the USB interfaces on most DAC were terrible.

You would literally get "crackles and pops" especially at higher res streams (e.g. 96k). Usually Coax SPDIF was the "best" way to connect with a DAC.

It seems that the USB issue is now "solved" with XMOS 208 and 216 chips. But it seems to me that USB is fundamentally a poor interface for audio, and we have had to invest a lot to work around USB's limitations.

It also seems that almost all PCs motherboards have dropped Coax SPDIF output, but almost all of them still have TOSLINK SPDIF output.

So two questions:

1) why don't more of you have PCs setup as the fundamental source using PCIE SPDIF output rather than USB?
2) why did mono makers select TOSLINK over Coax for their remaining SPDIF interface? (I recall TOSLINK is almost always more jitter/less bandwidth)?

I will now confound you I use a Windows PC with Xonar PCI-E card and optical SPDIF out to a fully digital amp, another Debian PC with USB out to same amp, and a Debian server (HP Proliant) running a UPnP renderer with USB audio out to a Topping D10 which then passes the digital stream to that same amp via COAX. Yes, I use optical, coax and USB all together. Oh, the heresy, the joy. But that's because I have a few different machines and slightly different requirements for certain of them.

But the real reason most people use USB out to external DAC is because motherboard manufacturers skimp on the integrated DAC and also save a penny by selling their boards without a SPDIF header. You can always buy a PCI-E soundcard and Asus's excellent SPDIF expansion board is always available very cheaply on ebay, but actually the reasonable thing to do with an external USB capable DAC is to just plug the thing into any spare USB port and enjoy the simplicity and most of all the music.

 

[VintageFlanker]

Interesting
My Douk U2 is also good sounding.

Does Douk U2 (XMOS) driver support ASIO? At almost twice the price of the PHIREE U2S, not sure about what it can bring to the table, except 192Khz support.

 

[Tangband]

Does Douk U2 (XMOS) driver support ASIO? At almost twice the price of the PHIREE U2S, not sure about what it can bring to the table, except 192Khz support.

The Douk U2 has three separate clocks , one for dsd and one for 44,1 kHz, the third for 48 kHz.
It would be very interesting to see measurements on this unit.
Maybe the jitter is much lower ? Or worse?
My ”sky song” with battery-power brings slightly better sound to my Genelec 8340 than Douk U2.

Digital out : Yamaha wxc50, skysong , Douk U2 - soundreview.

I have recently done a test in longterm listening with three units used as digital preamps to the digital input of my Genelecs . 1 . Yamaha wxc 50 digital out , spdif , pre amp mode . AirPlay from iPhone with Apple Music lossless. 2. Sky song - a chinese USB bridge with xu208, lt1963...

www.audiosciencereview.com

 

[dufferdan]

Schitt had to work on their usb interface because until unmasked here their usb isolation was unusually schitty.

I seem to recall when I purchased my Bifrost 1 that Jason was pretty clear at the time that USB was very problematic to implement for audio and while they included a USB connector, they certainly suggested either optical audio or coax connections. That DAC is 12 or 14 years old, and while I have it hooked up to my Mac via the optical audio connector for headphone use, I am likely to update that with a Bifrost 2. Doing so will also put me in a ready state for when Apple updates to a new silicon 27” Retina iMac, hopefully in the near future. I hadn’t really lurked around here for several years, so to now see USB as the standard for audio and outperforming Toslink is a bit of a revelation.

so related to this, and referencing another thread where Amir tests coax out from a USB tesT signal being put into a converter to coax toslink out, the Topping D30 seemed to totally clean up the output.

For my main 2 channel system in the living room, I will be picking up a Topping D70S MQA version for maximum flexibility. My question becomes would be, should I use either coax or optical audio out from my c. 2000 Rotel 5 disk CD player out to the Topping or just leave it as RCA out? Are the updated DAC technology worth it. Listening will tell the tale I am sure. I am thinking that when I upgrade the receiver to a new pre-amp/amp combo or upgraded Cambridge receiver with balanced input, the balanced out from theTopping might give me a little more punch. Thinking also of replacing the Squeezebox Touch with a Cambridge CXN 2. Then the choice is, leave it to balanced out to receiver or pre-amp or run that thru the Topping. Thinking the DAC in the CXN2 is probably good enough, though i haven’t seen a test here for that unit. Would be keen to though.

Any thoughts/criticisms of my logic or lack thereof welcome!

 

[Kal Rubinson]

1) why don't more of you have PCs setup as the fundamental source using PCIE SPDIF output rather than USB?

It won't do multichannel.

 

[cheapsoundguy]

It won't do multichannel.

Um… none of the DACs do multichannel do they? Sure and AVR will, but that’s not what 90% of this site is about. Or am I missing something?

 

[Trell]

Um… none of the DACs do multichannel do they? Sure and AVR will, but that’s not what 90% of this site is about. Or am I missing something?

There are more than a few DACs that are multi channel.

 

[Kal Rubinson]

Um… none of the DACs do multichannel do they? Sure and AVR will, but that’s not what 90% of this site is about. Or am I missing something?

I own 2 and there are others.

 

[krabapple]

There is also ADAT that can have 8 channels 24/48 but I don't know of any receiver that has that support. RME supports both ADAT and S/PDIF on their optical input/output.

that's a total nonstarter.

All that needs to happen is for both laptop and AVR USB I/O to be compliant with pro audio USB (which is already long used for multichannel)

Apparently it hasn't?

 

[Trell]

that's a total nonstarter.

All that needs to happen is for both laptop and AVR USB I/O to be compliant with pro audio USB (which is already long used for multichannel)

Apparently it hasn't?

I know but can't I dream about ADAT? I'm perfectly fine with 8 channels using 24 bits at 48 kHz sample rate.