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An epiphany as a result of using a USB / SPDIF converter

beammeup

beammeup

pfm Member
I have had a bit of an epiphany – I was comparing two DACs side by side – an interesting Starting Point System DAC-3 (battery powered TDA 1543 based) and my current Arcam irDAC.

The connection was USB (using AudioQuest Forest USB cable) from an old netbook PC direct to the USB input of both DACs. I proceeded to play music and found that both DACs were somewhat uninvolving.

I could not work out why the sound was quite flat and lifeless. Later I decided to put an old TeraLink USB / SPDIF converter between the computer and the DAC, this opened out the sound considerably! Far beyond any differences you are likely to get between DACs. If I had done my comparison with the irDAC tethered to SPDIF and the SPS DAC-3 tethered directly to USB then my conclusion would have been that the irDAC was way better – but now I know this is certainly not the case!

Trouble is, the TeraLink converter sync’d fine with the Arcam but not so the SPS DAC-3, something I have yet to determine as to why because comparisons can’t be made unless they are on a level platform; but in conclusion the interface is far more influential than the DAC. Good ol’ SPDIF.

If you’ve always tried to get a good sound directly from the USB out of a computer – try a good SPDIF converter first – it’s certainly worth it even if you don’t believe it!
 
I have had a similar experience albeit many years ago when I bought a HiFace to connect to a Supernait from a Macbook. It was a very noticeable move for me. USB ports vary too much IME but you can get a more than fine sound out of them if you do a little homework.

Now, funnily enough i'm back to USB through a Schiit Audio Wyrd HUB, in addition to using a USB port that isn't shared by anything on a trash can Mac Pro. Sounds more than fine. Using a port that isn't shared should be mandatory IME.
 
Thetiminator said:
IME a good USB/spdif converter always betters direct USB in.
Click to expand...

Why would the extra conversion stages improve things? Even more relevant, asynchronous USB allows disconnecting DAC clock from the source clock - with spdif you need an asynchronous sample rate converter to accomplish the same.

Optical does give you galvanic isolation, copper spdif doesn't.
 
You can certainly get a different sound from the various USB to SPDIF convertors, but better? As usual, it depends on many things. I've built a number of convertors, based on XMOS and CM6631As, powered by various low-noise regulators, and they all sound different. The best sound I've gotten so far's USB from Melco into Chord DAC, via iFi 3.0 USB Galvanic isolator. Properly implemented USB's likely to be better than SPDIF.
 
My experience is that in the right stack a DDC can give significant benefit. Over the years I have used a few, currently I am using the Singxer F1 fed from my microRendu and into my Border Patrol DAC.

When I bought the Border Patrol I could have got one with an USB interface but these appear to be the subject of quiet rapid change.

Introducing the mR/F1 did introduce me to the world of ground noise, which took me the best part of a year to identify and then fix. So by adding widgets I found I introduced some complexity, electrically. That said things are now running well and I have no complaints.

Personally I prefer the F1 as I can determine how it is powered, rather than rely on a manufacturers choice of PSU.

M
 
Purite Audio said:
Some measurements,
https://audiosciencereview.com/foru...-pdif-vs-usb-which-is-better.1943/#post-51250
Click to expand...

For those who don't have time to check out the link:

"none of these measurements indicate any audible difference. The measurements where different, show really small levels of noise and distortion. I can't make a case for audibility of any of it.

Conclusions
As seen from pure measurement point of view, there was no case where USB was worst than S/PDIF. Indeed the reverse was true in that S/PDIF was noisier in some DACs. So the default assumption that somehow S/PDIF has some advantage over USB is simply false."
 
Well, I have used both a dedicated USB-card with external power and a NuForce U192s USB to spdif-converter into a Metrum Octave mk1 and that combo comfortably beat an Ayre QB9 Dac fed directly from a computer USB port. So I know what I prefer.

The same result came about when I tested a Hegel 12 DAC. Via my NuForce USB to spdif-converter , the sound was better - To My Ears.
 
I have used a hiFace Two in the office system upstairs for some time now and have been very pleased with the result.
 
Rosewind said:
Well, I have used both a dedicated USB-card with external power and a NuForce U192s USB to spdif-converter into a Metrum Octave mk1 and that combo comfortably beat an Ayre QB9 Dac fed directly from a computer USB port. So I know what I prefer.

The same result came about when I tested a Hegel 12 DAC. Via my NuForce USB to spdif-converter , the sound was better - To My Ears.
Click to expand...

Metrum is a non oversampling design isn't it?
Keith
 
I bought a cheap eBay USB to SPDIF adaptor, since I figured it'd sound better than my PC's onboard DAC for my office system. It sounded like absolute arse. Harsh highs and lacking midrange. The onboard audio from my PC was, whilst still crap, better! I bought a HifiMeDIY "Tiny USB DAC" and it sounds absolutely wonderful.

I had previously thought that the conversion to SPDIF was largely software-driven, but clearly I was wrong. You don't need to spend much (the Tiny USB DAC was £30) but cheap tat is, well, tat.
 
Julf said:
Why would the extra conversion stages improve things? Even more relevant, asynchronous USB allows disconnecting DAC clock from the source clock - with spdif you need an asynchronous sample rate converter to accomplish the same.

Optical does give you galvanic isolation, copper spdif doesn't.
Click to expand...

Don't ask me to explain the technicals but IME I've found with computer audio that the more re-clocking and clean power (must be battery power supplies for ultimate sound quality) you can give it the better. My custom made server is now a 9 box affair!!! :eek:

But to be fair it is stunning, the best source I've had or heard. Noticeably better than the Esoteric K-01 I had and the Aurender W20 I tested.
 
Thetiminator said:
Don't ask me to explain the technicals but IME I've found with computer audio that the more re-clocking and clean power (must be battery power supplies for ultimate sound quality) you can give it the better. My custom made server is now a 9 box affair!!! :eek:
Click to expand...

Which is kind of strange considering each reclocking stage isolates the clock domains, so that the output clock is entirely independent of the incoming clock. It is like having a chain of people throwing a ball to each other. Does it matter, when the ball gets to the last person, if the first person threw using their left or right hand?
 
My Halide Bridge is better than any CD transport I have tried. The first unit to make me a believer in the superiority of computer audio. My DAC is SPDIF only, as the designer sees different design requirements for the USB version.
 
Thetiminator said:
Don't ask me to explain the technicals but IME I've found with computer audio that the more re-clocking and clean power (must be battery power supplies for ultimate sound quality) you can give it the better. My custom made server is now a 9 box affair!!! :eek:

But to be fair it is stunning, the best source I've had or heard. Noticeably better than the Esoteric K-01 I had and the Aurender W20 I tested.
Click to expand...

Be interested to hear what that setup consists of. I'm running an RPi based setup personally and I'm pretty impressed with it so far.. The PSU side of it needs work and that's the next step of the project!
 
"Be interested to hear what that setup consists of. I'm running an RPi based setup personally and I'm pretty impressed with it so far.. The PSU side of it needs work and that's the next step of the project!"


Custom server with Linux OS. I can boot in Windows or Linux and Linux sounds way better. Manufacturers spend a lot of time trimming down OS's as much as possible for SQ, you can't get any more trimmed down than Linux.
Mahussive PS for the server PS - BPS's don't work for the main power - don't know the technicals but apparently computers power requirements work in a way that batteries can't do the job.
Internal SSD with it's own BPS - BPS's are mostly SOTM mBPS's with the exception of one Uptone LPS-1. The SOTM's generally sound much better.
External PS for motherboard.
Fibre optic out to Adnaco outboard USB stage with it's own BPS.
Audioquest Jitterbug's on ins and outs of Adnaco.
Chord Sarum Tuned Array USB cable to Regen ISO with it's own BPS
SOTM ASB/SPDIF converter (upgrade with Femto clock and it's own BPS
Audioquest Wild AES/EBU to Boulder Dac.

It's actually 11 boxes strictly speaking :eek:

I think that's everything :p

Edit:
Every step has brought a noticeable improvement in SQ, I'd sort them biggest to smallest difference like this:

Main PS for server
Femto USB/SPDIF converter
Chord Sarum USB cable
Adnaco USB stage
Regen ISO
BPS for USB/SPDIF converter
BPS for Regen
PS for motherboard
Audioquest Jitterbugs
 
The Allo DigiOne board for an RPi is so much better than basic spdif boards for the RPi. The DigiOne reclocks, is galv isolated and has its power cleaned up. Finally I have the RPi sounding as good as a well setup USB PC. I mention this as there are so many variables to all this and we will have variable results as no doubt none of us have exactly the same setup.

Oh yes...battery power is great.
 
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