Wavelength WaveLink Asynchronous USB to S/PDIF converter.

[JayDee]

While I know better than to make solid claims without having heard it...... your first link says essentially nothing...

I realized that few here are likely to be satisfied by the content of my first post over at Head-Fi. That's why I included links to both threads. If you read through the second one, I think you'll find that most of the questions or criticisms that have been or are likely to be raised here have already been addressed there - though of course they may not be to everyone's satisfaction. I didn't want to post lengthy, redundant info here when I'd already written it out once.

[Beefy]

I don't really see how "you wouldn't understand because you aren't willing to pay that much" is addressing criticism.

I'm naturally a skeptic, and really despise audiophool bullshit...... but your loopback tests do look nice. So why not try to nail the coffin by similarly testing some competing solutions? Or doing some properly controlled blind listening tests?

[morphsci]

For those who may have missed them over at head-fi, I've included links below to the measurements in question.

These tests were made with an M-Audio Audiophile 192 soundcard. First, a baseline test with a cable connecting the SPDIF output to the SPDIF input:

SPDIF loopback

Next, the Diverter was placed in the otherwise identical signal path:

Diverter to SPDIF loopback

So after subjecting myself to the entirety of the "discussion" at head-fi I would like to know if you have the results of the above tests with other 24/96 converters? From my perspective your measurements are interesting but with no frame of reference relative to other converters they really don't mean much.

Edit: Beefy you are too quick my man.

[Beefy]

Edit: Beefy you are too quick my man.

You sound just like my girlfriend

[morphsci]

You sound just like my girlfriend

Heh.

[Dreadhead]

What's awesome about that test is that it shows that the converter is as good at a M-audio 192 that is what 1/5th the price? Yay!

[cetoole]

More I am not sure how what that test shows is actually relevant. I mean sure, its good that your converter isnt making significant changes to the data the receiver decodes, but really, how is it going to add significant THD or IMD? Sure, you get the normal big THD+N spike at 1khz from the 1ms resampling, but beyond that. Measurements showing that it is truly bit perfect would be good, and especially since you talk about it being a true 75ohm interface, I would love to see some TDR plots.

[JayDee]

I don't really see how "you wouldn't understand because you aren't willing to pay that much" is addressing criticism.

I'm not sure how you distilled that message as the essence of what I wrote. That was certainly not my intent.

I'm naturally a skeptic, and really despise audiophool bullshit......

That makes two of us.

but your loopback tests do look nice.

Thank you!

So why not try to nail the coffin by similarly testing some competing solutions? Or doing some properly controlled blind listening tests?

Those are valid points. But I wasn't claiming to be offering a comprehensive suite of tests with the results I linked to; I was basically trying to throw a bone to the people that kept calling for some kind of testing, and I was also trying to show those who own a Diverter (and are so inclined) that they could run some tests themselves. And at this point (schedule-wise) I'll have to leave it to others to provide comparative test data or blind listening tests. There is also the issue of one manufacturer providing test data for the products of others - I would rather not deliberately pick fights with fellow manufacturers. They would likely be suspicious of my test results, just as I would theirs (unless I knew them well enough to be confident there was no subterfuge going on).

[JayDee]

So after subjecting myself to the entirety of the "discussion" at head-fi I would like to know if you have the results of the above tests with other 24/96 converters?

I have tested one other that I had access to through a friend, but generally speaking I don't find it practical or a wise use of development funds to maintain an inventory of competitive products here for testing.

From my perspective your measurements are interesting but with no frame of reference relative to other converters they really don't mean much.

The baseline SPDIF to SPDIF loopback is the frame of reference in this case - the only point of this test was to establish the Diverter's "transparency" if you will, not to compare it to competitive products.

[JayDee]

... but really, how is it going to add significant THD or IMD?

It is entirely possible for poorly-designed digital gear to produce significant, even severe, THD and IMD products. For instance, take a look at the differences between an excellent asynchronous sample rate conversion algorithm and a bad one - it isn't subtle.

Measurements showing that it is truly bit perfect would be good

Do you have specific test methodology in mind?

and especially since you talk about it being a true 75ohm interface, I would love to see some TDR plots.

And I would love to provide them - but it will have to wait. If I did nothing but run all of the measurements people requested, it would be a full-time job for me.

[cetoole]

It is entirely possible for poorly-designed digital gear to produce significant, even severe, THD and IMD products. For instance, take a look at the differences between an excellent asynchronous sample rate conversion algorithm and a bad one - it isn't subtle.

Not saying that digital gear cant, but that a simple format converter really really shouldn't. This is quite different than ASRC. This is (unless I am sorely mistaken) nothing more than receive and transmit, no intended alteration of the data. Heck, if you are getting significant THD+IMD, then you certainly arnt passing bit perfect.

Do you have specific test methodology in mind?

Even something as simple as just passing HDCD and/or DSD data would be sufficient.

And I would love to provide them - but it will have to wait. If I did nothing but run all of the measurements people requested, it would be a full-time job for me.

Ah, I figured this would be a standard measurement for something employing high speed digital design techniques and making a statement like the first one here, which is, of course, correct, since while the data stored may be digital, what is transmitted over that coaxial cable certainly doesnt consist of perfect square wave pulses.

[Dusty Chalk]

I think you meant DTS, not DSD.

[Beefy]

And at this point (schedule-wise) I'll have to leave it to others to provide comparative test data or blind listening tests.

Why am I not surprised?

I would have thought at $1300 a pop, you could make time to at least back up all the crap you've been posting.

[cetoole]

I think you meant DTS, not DSD.

You got me.

[Grahame]

And at this point (schedule-wise) I'll have to leave it to others to provide comparative test data or blind listening tests.

Why am I not surprised?

I would have thought at $1300 a pop, you could make time to at least back up all the crap you've been posting.

So do I take it this means that there is no QA testing to ensure built units measure in spec (what ever that even is)?, or listening tests to check for defects?

Sennheiser, manage FR plots tied to individual Serial numbers on the HD-800's.

[manaox2]

My biggest concern is that there is no way to audition this thing unless you wait for a meet, pay $250 if you don't like it, or plan a trip to Utah. Granted the same thing could be said about many products, usually there are measurements, comparisons between competitors by reviewers, large numbers of reviews, company reputations, and often internal pictures or detailed descriptions to help buyers decide. I think I've mentioned that ad nauseam on head-fi already. I'm sure this will change for the Diverter, but I would have expected the manufacturer and distributors to support the process by setting up more information and opportunities.

[Beefy]

So do I take it this means that there is no QA testing to ensure built units measure in spec (what ever that even is)?, or listening tests to check for defects?

Not to mention that it strongly suggests there were no comparative measurements performed during the design process, to confirm the product's performance level.

My biggest concern is that there is no way to audition this thing unless you wait for a meet, pay $250 if you don't like it, or plan a trip to Utah. Granted the same thing could be said about many products, usually there are measurements, comparisons between competitors by reviewers, large numbers of reviews, company reputations, and often internal pictures or detailed descriptions to help buyers decide.

But, but, but....... scootermafia says it is good! And it just keeps getting better as it burns in!

[screaming oranges]

...You've been playing without an opponent, which is, as you may have guessed... against the rules.

[screaming oranges]

Note: I am not the opponent though. I don't know crap.

I will refrain from speculating and just wait patiently for its arrival.

[morphsci]

I have tested one other that I had access to through a friend, but generally speaking I don't find it practical or a wise use of development funds to maintain an inventory of competitive products here for testing.

Hmm... personally I like to know as much about my competition as possible.

The baseline SPDIF to SPDIF loopback is the frame of reference in this case - the only point of this test was to establish the Diverter's "transparency" if you will, not to compare it to competitive products.

It does not provide a frame of reference for how much better it is, or not, than other converters. But if you prefer I ignore the man behind the curtain I certainly have no problem with that.

[JayDee]

...You've been playing without an opponent, which is, as you may have guessed... against the rules.

I'm laughing - that was a good one. One of my favorite movies BTW.

If I wanted an opponent (or several) it appears I came to the right place.

[Pars]

Isn't the whole point of this device to take USB audio and convert to S/PDIF to a DAC? Wouldn't jitter measurements as well as ensuring that the data is preserved bit-perfect be the meaningful measurements?

Of course you have no control of the quality of the S/PDIF interface on the DAC end , so I'm not sure how you would go about offering a meaningful measurement, particularly of jitter.

[JayDee]

Hmm... personally I like to know as much about my competition as possible.

As do I, but the key word here is "possible" - sure, ideally speaking, it would be great to have a copy of every competitive device on the market. But it's hardly practical to do so, and even if it were I would question the value of doing it relative to how those resources might be otherwise employed. As I've already stated, I have measured several others, and I didn't go into this (or any other project) ignorant of my competition. That's just basic R&D.

It does not provide a frame of reference for how much better it is, or not, than other converters.

I never claimed that it did. This was a difference test, not an absolute test, designed to show one thing, and one thing only: that the Diverter is, at least as far as the methods of this test allow, transparent in the way it handles digital data. The results of the test would be valid for comparison if and only if the testing device were calibrated to some kind of recognized standard, allowing anyone else with similarly calibrated equipment to repeat the test results with some other device. I wasn't attempting to be nearly that formal or comprehensive in this test.

[JayDee]

Why am I not surprised?

Look, you can float all the theories you like about the real reasons behind my not posting comprehensive Diverter measurements. I have already stated that more will be forthcoming at such time as I am able to prepare them for public consumption. Despite what many here seem to think, this doesn't mean I haven't performed any, or that I don't recognize their value.

I would have thought at $1300 a pop, you could make time...

As it turns out, the equations of running a small business don't quite balance out that way, at least for me. When you start your own audio business, you're free to prioritize your time and resources towards pleasing everyone on the forums. Let me know how that works out for you.

[JayDee]

So do I take it this means that there is no QA testing to ensure built units measure in spec (what ever that even is)?, or listening tests to check for defects?.

No, not at all - every single Diverter that goes out the door is subjected to both listening and instrumentation tests.