15 USB/SPDIF converters shootout

[Musicophile]

A forum discussing audio in strictly objective terms would bore everyone to tears, and we would probably all end up with gear that measures terrifically and sounds like crap.

 

We didn't have an objectivist/subjectivist debate for at least a week or so. It is high time to start a new one!

[Superdad]

Well, not too many by appearances as much as some might hope that async USB was the silver bullet.

 

There is nothing preventing a DAC manufacturer from including a USB input inside their DAC that performs as well as an external USB>SPDIF converter. The elements are the same, with almost everyone using one of the very good XMOS chips. It is largely about the clocking, the isolation, and the power supply.

I am not an engineer, but have been working with an exceptionally talented one (John Swenson) for many years and am listening to a co-developed DAC from him right now.

 

Logically, properly done USB>I2S>DAC chip should sound better than USB>SPDIF>SPDIF driver>SPDIF receiver>DAC chip.

[4est]

There is nothing preventing a DAC manufacturer from including a USB input inside their DAC that performs as well as an external USB>SPDIF converter. The elements are the same, with almost everyone using one of the very good XMOS chips. It is largely about the clocking, the isolation, and the power supply.

I am not an engineer, but have been working with an exceptionally talented one (John Swenson) for many years and am listening to a co-developed DAC from him right now.

 

Logically, properly done USB>I2S>DAC chip should sound better than USB>SPDIF>SPDIF driver>SPDIF receiver>DAC chip.

 

Agreed.

[bhobba]

Both are measurable, but yet scope/analysis is missing. I'm fearful of this exercise being nothing more than pure subjectivity.

 

That's not the case. The best converters have jitter below 10ps which requires very rare special equipment to measure. Steve Nugent for example cant directly measure it and had to 'guess' it via other means. And yes it is audible. For example the Audiophellio has a slightly lower jitter than Steve's Off-Ramp yet many like myself prefer the Off-Ramp. Evidently the real critical thing is not so much the level of jitter but its spectrum - which is even harder to measure. IMHO measurements are not the way to go here - but rather listening to it.

 

Thanks

Bill

[bhobba]

Are there any DACs at this time, at any price, whose USB input is not bettered by a first-rate external USB to S/PDIF converter?

 

Yes - my PDX and Playback Designs MPD3.

 

Thanks

Bill

[bhobba]

A forum discussing audio in strictly objective terms would bore everyone to tears, and we would probably all end up with gear that measures terrifically and sounds like crap.

 

Yea - in the early days of SS there were amps with amazingly low distortion produced by massive amounts of feedback yet they sounded like crap - it was described as though all the life had been sucked out of the music. Nowadays its used a lot more judiciously but the old amps still measured better.

 

Thanks

Bill

[firedog]

According to Adam, the MSB DAC IV falls into that category. I will soon find out for myself it I agree. Currently using it with the OR5 + monolith PS, and will try the USB connection shortly.

 

I love Steve's products, but if the MSB DAC IV needs an OR5 to improve its sound, you are not getting what you paid for.

[4est]

I love Steve's products, but if the MSB DAC IV needs an OR5 to improve its sound, you are not getting what you paid for.

 

I think that you are taking this backwards in that the MSB does NOT need a converter.

[mayhem13]

That's not the case. The best converters have jitter below 10ps which requires very rare special equipment to measure. Steve Nugent for example cant directly measure it and had to 'guess' it via other means. And yes it is audible. For example the Audiophellio has a slightly lower jitter than Steve's Off-Ramp yet many like myself prefer the Off-Ramp. Evidently the real critical thing is not so much the level of jitter but its spectrum - which is even harder to measure. IMHO measurements are not the way to go here - but rather listening to it.

 

Thanks

Bill

 

Pure speculation on your part as to the audible level of jitter.....and it is quite measurable with the correct equipment. Digital communication and manufacturing rely heavily on reduced jitter levels to assure accuracy. If jitter levels are in the Pico range and you'd like to make a point for audibility, I have some beachfront property in Montana that's a real bargain too!

[mayhem13]

A forum discussing audio in strictly objective terms would bore everyone to tears, and we would probably all end up with gear that measures terrifically and sounds like crap.

 

Agreed....but certainly you don't suggest to align that point with the OPs subjective opinions on clear audible differences between USB/SPDiF converters. The OPS assertions would suggest that the reference DAC used is not capable of properly reducing/eliminating jitter, but passing through whatever comes along.

[Blake]

Mayhem- I may be wrong but I did read somewhere that the Audio Precision Series 2 Test System is considered the industry reference standard measurement equipment, at a cost of $19,000. I*think* I read this on AMR's website but cannot locate it at the moment. I am by no means an expert in the area of measurement devices so please correct me if I am mistaken. Do you expect our forum members to use such equipment before posting any subjective opinions about audio gear?

 

And if we don't use the industry standard measurement equipment, could we be certain that the lesser measurement equipment used was sufficiently sophisticated and accurate to give us valid results?

 

Can we definitively say that the Audio Precision Series 2 Test System is sophisticated and accurate enough to measure everything that humans are capable of hearing and perceiving? And even assuming we can answer that question in the affirmative, are the leading scientists and researchers in this field confident that we can correlate these measurements to what a listener's brain actually perceives?

 

Measurements are a great tool, but are they the be all end all of the discussion? Why is it necessary to draw a line in the sand and make this a black and white issue? What is wrong with using measurements and subjective listening? That makes sense to me. I am not a subjectivist or objectivist, I am a sobjectivist.

 

Perhaps I misunderstand your actual views on this subject, but my sense is that you are 100% objectivist, and are dead set against any subjective thoughts or analysis. If so that is cool with me, but I at the end of the day, I personally cannot see what is wrong with trusting one's ears.

 

That is what I do when I flip on my stereo at the end of the day. Apologies in advance for getting off the topic at hand. Perhaps this should go in a new thread.

[Superdad]

Please don't feed our troll!

[Musicophile]

Please don't feed our troll!

See my comment on top of the page :-) was just a matter of time.

[Blake]

Oh, I don't know about "troll", perhaps something more friendly, like "Gruff, But Lovable Gus", the character from the David Letterman Show?

 

Even though I very frequently disagree with Mayhem, and I have engaged in a few "dust ups" with him in this forum, he does have some good points from time to time.

[Blake]

Actually, I have wondered about having a Forum subcategory "The Objectivist/Subjectivist Debate". We could then steer all such discussion to that sub-forum.

 

For example, someone throws out an objectivist/subjectivist argument in the middle of a cable review thread, someone can kindly post "please move this discussion to the "Objectivist/Subjectivist Debate" forum? Although I can be a sarcastic sob, I am serious about this suggestion. I think it makes sense.

[mayhem13]

Please don't feed our troll!

 

No troll here pal......plenty of posts under my belt here, and enough professional experience to understand the difference between price biased product evaluation and useful information.

[mayhem13]

Blake

 

Certainly not suggesting the use of such an expensive piece of equipment BUT there was a post suggesting that the audible difference between USB/SPDiF converters was Jitter driven. Mind you now, we're not talking DACs here, just format converters. And the OP suggested stark audible differences between them. If I'm correct, a high end reference DAC was used for all. The DAC is responsible for handling jitter, correct? So again, if you wouldn't mind ( notice non arguementative tone) kindly share your viewpoint on what might be responsible for these audible differences?.......and if you would also consider the more 'likely' answer.

[robbbby]

Any Meitner MA-1 owners that use, or have used, spdif converters with their MA-1, specifically the alpha usb?

[Blake]

So again, if you wouldn't mind ( notice non arguementative tone) kindly share your viewpoint on what might be responsible for these audible differences?.......and if you would also consider the more 'likely' answer.

 

No problem at all mayhem. Why the difference in sound quality? Well, since I am not an engineer, I could not say. I could simply repeat what is said in marketing materials but that would be pointless.

 

However, I can say with 100% certainty that they do impact sound quality. How do I know this? Try and buy. And no, I don't have endless piles of cash laying around and it is not me trying to justify spending money. It is the exact opposite. I have lots of other hobbies and would much prefer spending my money on other things.

 

Having 3 different converters at my house, in my system, trying NOT to hear a difference (because I would sincerely prefer not to spend the money, I am not a newbie off the street that bought everything my dealer told me to buy and then I try to justify the cost, I have been fully engaged in this audio hobby since 1997, not as long as some, but longer than others), yet it is absolutely, positively undeniable that these converters impact the sound quality. So yes, I did consider that these devices might not make a difference, but that was not my finding.

 

And to be clear, I believe there are instances where adding a converter might negatively impact sonics. I am simply reporting my findings. Some members on this forum, whose ears I trust, experimented and found converters did not improve things with their system and I believe them. This is very much a system dependent thing as far as I can tell.

[Superdad]

Blake

 

...Mind you now, we're not talking DACs here, just format converters. And the OP suggested stark audible differences between them. If I'm correct, a high end reference DAC was used for all. ...kindly share your viewpoint on what might be responsible for these audible differences?.......and if you would also consider the more 'likely' answer.

 

Sure: USB input, clocks, S/PDIF drivers (there are many ways to produce an S/PDIF signal), power supplies. Every one of the converters auditioned by the OP is designed differently. So why does it surprise you that there audible differences?

[mayhem13]

Sure: USB input, clocks, S/PDIF drivers (there are many ways to produce an S/PDIF signal), power supplies. Every one of the converters auditioned by the OP is designed differently. So why does it surprise you that there audible differences?

 

I'm not surprised.....but convinced there are no audible differences with a quality DAC on the other end. You gotta draw a line somewhere. I draw mine here.

[tpaxadpom]

Mayhem- I may be wrong but I did read somewhere that the Audio Precision Series 2 Test System is considered the industry reference standard measurement equipment, at a cost of $19,000. I*think* I read this on AMR's website but cannot locate it at the moment. I am by no means an expert in the area of measurement devices so please correct me if I am mistaken. Do you expect our forum members to use such equipment before posting any subjective opinions about audio gear?

 

And if we don't use the industry standard measurement equipment, could we be certain that the lesser measurement equipment used was sufficiently sophisticated and accurate to give us valid results?

 

Can we definitively say that the Audio Precision Series 2 Test System is sophisticated and accurate enough to measure everything that humans are capable of hearing and perceiving? And even assuming we can answer that question in the affirmative, are the leading scientists and researchers in this field confident that we can correlate these measurements to what a listener's brain actually perceives?

 

Measurements are a great tool, but are they the be all end all of the discussion? Why is it necessary to draw a line in the sand and make this a black and white issue? What is wrong with using measurements and subjective listening? That makes sense to me. I am not a subjectivist or objectivist, I am a sobjectivist.

 

Perhaps I misunderstand your actual views on this subject, but my sense is that you are 100% objectivist, and are dead set against any subjective thoughts or analysis. If so that is cool with me, but I at the end of the day, I personally cannot see what is wrong with trusting one's ears.

 

That is what I do when I flip on my stereo at the end of the day. Apologies in advance for getting off the topic at hand. Perhaps this should go in a new thread.

Audio Precision 2722 is an industry standard (JA from Stereophile has one). There are cheaper packages like 500 series. I have access to AP2722 and measured some usb-spdif converters. I never heard BADA converter, and if someone wants to ship me one I can provide measurements as well as subjective test vs Diverter HR in my system.

[tpaxadpom]

That's not the case. The best converters have jitter below 10ps which requires very rare special equipment to measure. Steve Nugent for example cant directly measure it and had to 'guess' it via other means. And yes it is audible. For example the Audiophellio has a slightly lower jitter than Steve's Off-Ramp yet many like myself prefer the Off-Ramp. Evidently the real critical thing is not so much the level of jitter but its spectrum - which is even harder to measure. IMHO measurements are not the way to go here - but rather listening to it.

 

Thanks

Bill

I would be very careful comparing jitter measurements without knowing how they were done and what equipment was used.

At one point in time I preferred one converter with measured jitter 10X higher than the other one. Placebo is out of the question as I owned the better measuring one.

[guydebord]

I would be very careful comparing jitter measurements without knowing how they were done and what equipment was used.

At one point in time I preferred one converter with measured jitter 10X higher than the other one. Placebo is out of the question as I owned the better measuring one.

 

Exactly! There are so many other factors that come into play, plus jitter is such an old conversation, I have been reading about this since 1981.... We are in 2013 arguing the same pointless things that get nowhere. I call this thread hijacked.

[Bob Stern]

I expect that different DACs respond differently to various types of noise and jitter. Therefore, the choice of DAC will strongly affect the rankings of USB > S/PDIF converters.

 

On the other hand, if a USB > S/PDIF converter were essentially perfect in eliminating noise and jitter, it should be the best for every DAC.

 

So it's possible that the very top ranked USB > S/PDIF converter(s) will be best universally, but that the relative rankings of the lesser converters will be system-dependent.