[matanoosh]

Hi all. I'm a newbie here, from a far away foreign country.
Just had the Isabellina at home for an audition. Very impressive DAC indeed. Unfortunately I had nothing to compare it to in its price range.
Although extremely musical and pleasant, there's one thing that keeps coming back when I think about making the decision to purchase:
I can't understand why choose a NOS chip for the d2a conversion. I'm not trying to be over-technical here, no sir. I'm merely a listener, not an engineer or even a technician. But I'm chasing my own tail trying to explain to myself the purchase of a brand new DAC which is based on a two-decade old technology, even though it DOES sound wonderful.

Ok, so some people might say: "if it sounds good why don't you buy it? this the only thing that mattes after all". But.. I'm afraid it's not so simple for me. We can take 5 or 6 dacs based on the same chip, and they all sound completely different. Not just different, but one can be much better than the other. Hell, my friend just built himself a NOC dac with an array of several chips together (I think it was working parallely. He wanted to sell it for $500 (and indeed, it sounds 25% of the Isabellina's performance ). But why choose an old chip, especially all the rest is so well thought of and implemented (inputs, power supplies, analog outputs, filters etc)? I just don't understand it and I don't have anyone here to explain this to me.

So even if a Wadia sounds like a computer and not a music maker, it does have "state of the art" technology. Is it really impossible to build a musical dac based on modern-day technology?

What am I missing?

... I just wish I could buy Isabellina and be happy with it .

-Matt

[richidoo]

This might help. It took me a while to learn to hear the difference, but now it is unmistakable and I prefer NOS conversion. Some of the newest chips are very good though.
 
btw, NOS in this case stands for "non-oversampling," not "new old stock."
Rich

[wilsynet]

It's only one theory that oversampling and upsampling DACs are superior.  Newer is always better, right?  But there's another theory, the one advocated by Ryohei Kusunoki that has had led us to an explosion of well implemented NOS DACs over the last few years.

The seminal tutorial on NOS DACs that Kusunoki wrote includes a brief explanation of the tradeoff between oversampling and non-oversampling.

http://www.sakurasystems.com/articles/Kusunoki.html

Is that sufficient, or should we be more persuasive?  I'm not a EE or physicist, but I'm happy to write more about my experience with oversampling versus non-oversampling.

Wilson

[Alwayswantmore]

I'm a former Wadia owner (830 with P upgrade, which is a second power supply, + expensive power cord & IC). Wadia oversamples the heck out of the signal. I trusted my ears when choosing the Isabella over the Wadia (I bought before the 6Moons review was written).

When making the decision, both Wadia and Isabella DAC were run into Isabella's line stage. Isabella's DAC is warmer and puts more flesh on instruments / vocals (texture / layers / etc.). While the difference could not be measured by a magnitude, now that I've spent time with Isabella's DAC, it would be tough to go back to the Wadia. I sold the Wadia and purchased an Apple Macbook -- which I love for the convenience.

To your question. I have absolutely no idea why the NOS dac sounds better, but did trust my ears to guide my decision.

Good luck with your decision. Kent

[Mariusz]

It's only one theory that oversampling and upsampling DACs are superior.  Newer is always better, right?  But there's another theory, the one advocated by Ryohei Kusunoki that has had led us to an explosion of well implemented NOS DACs over the last few years.

The seminal tutorial on NOS DACs that Kusunoki wrote includes a brief explanation of the tradeoff between oversampling and non-oversampling.

http://www.sakurasystems.com/articles/Kusunoki.html

Is that sufficient, or should we be more persuasive?  I'm not a EE or physicist, but I'm happy to write more about my experience with oversampling versus non-oversampling.

Wilson

Hey Wilson,
I was about to post that very same link............well, you beat me to it.


I like this explanation and tone:

This interview took place at 47Lab's listening room in Tokyo in July 1999. Attendants were
Mr. Junji Kimura(K)    the president and the chief designer of 47Lab,

Mr. Koji Teramura(T)    the marketing director ,
Yoshi Segoshi(Q)    of SAKURA SYSTEMS (US distributor of 47Lab products) as the interviewer.



Here are some of Mr. Ryohei Kusunoki quotes which may answer some of your questions:

"The difference between the non-oversampling [digital-filter-less] DAC and the conventional DAC with the digital filter lies whether you attach importance on the accuracy in the time domain or in the frequency domain. In other words, whether you choose the musical performance or the quality of a sound. This trade-off line defines the boundary of the current digital audio format."

"…in the next generation digital format offered today, the selling points for better sound are quantizing bit numbers and sampling frequency rates. It only means lowering of distortions and extension of frequency range. The appearance of CD was an epoch-making event as a new format to follow LP. It delivered the sound of the master tape to our listening room. It was a crystallization of efforts of the engineers of that time."

"A natural, stress-free sound that communicates the musicians' intention directly to you…is the sound of non-oversampling DAC. The feel of this sound is closer to that of analog reproduction."

[matanoosh]

Guys, I appreciate your replies.
And I stand corrected about NOS . I think that in this case, btw, NOS which stands for New Old Stock is also relevant, because if I'm not mistaken this is what Isabellina has - new chips which come from an old stock.

Regardless of that - I know that comparing to a Wadia machine, the Isabellina is infinitely more musical, pleasant and provides a more involving experience.

I'm not trying to understand why NOS is better than oversampling. For the lack of ability to compare to other dacs, I'm still hesitant about purchasing a DAC that utilizes an old technology. Are you guys saynig that in the last decade and a half, the digital realm technological advancements did not improve our listening experience? Perhaps this is indeed the case (subjectively, of course) - but I still find it hard to believe that other modern technology DACs out there are all less musical. For example, has anyone listened to the MSB power dacs? A completely different approach to DACs, I imagine, and I am very keen to listen to them...

To sum up my problem in one sentence - I find it difficult to purchase a DAC as if I was purchasing a tube amplifier. After all, except digital amps maybe, no major breakthroughs were introduced in this market in the last couple of decades. So a good design and good components will always get good sound. But is it really the same with DACs?

[Alwayswantmore]

Guys, I appreciate your replies.
And I stand corrected about NOS . I think that in this case, btw, NOS which stands for New Old Stock is also relevant, because if I'm not mistaken this is what Isabellina has - new chips which come from an old stock.

Regardless of that - I know that comparing to a Wadia machine, the Isabellina is infinitely more musical, pleasant and provides a more involving experience.

I'm not trying to understand why NOS is better than oversampling. For the lack of ability to compare to other dacs, I'm still hesitant about purchasing a DAC that utilizes an old technology. Are you guys saynig that in the last decade and a half, the digital realm technological advancements did not improve our listening experience? Perhaps this is indeed the case (subjectively, of course) - but I still find it hard to believe that other modern technology DACs out there are all less musical. For example, has anyone listened to the MSB power dacs? A completely different approach to DACs, I imagine, and I am very keen to listen to them...

To sum up my problem in one sentence - I find it difficult to purchase a DAC as if I was purchasing a tube amplifier. After all, except digital amps maybe, no major breakthroughs were introduced in this market in the last couple of decades. So a good design and good components will always get good sound. But is it really the same with DACs?

I sold high-end audio in the mid-'70s. At first I poured over spec sheet in an attempt to determine which product was better -- based on THD, wow and flutter, frequency response, power output, etc.

My assumption was that better specs meant better sound. Then I was introduced to Audio Research Tube amps (low-watt, high THD, expensive), and Lynn turntables (not very good specs compared to direct drives). Didn't take too long to figure out that specs had low correlation to what you hear.

Based on being a computer user the last few decades, it would be easy to assume that the world of digital is different. And that newer is always better and faster. But, Vinnie obviously has a good ear -- and seeks a certain type of sound. He's not afraid to take the road less traveled, and he also doesn't push specs much.

From my point of view, given enough money, you may be able to do better than the Isabella. But considering the sonic performance and fact you get a natural sounding tube linestage (that does not detract from resolution), an excellent musical DAC, and an optional headphone output for about the price of a good fairly high-end CDP, I feel the Isabella is a real steal. I also like the idea of only needing one good IC and a USB connector to tie it all together. Definately minimalist audio! Just my opinion. Your mileage may vary. Kent

BTW: Can you get a 30-day loaner on one of the competitive units. If so, you may want to order one and know first hand which unit best suits your listening needs.

[Mariusz]

Matanoosh
Old v.s new technology, is a debate which usually end up in the abyss of controversy and disagreement.
With that in mind follow your own gut feeling.

IMHO,  implementation, understanding and pushing the envelope of any technology is the key to successful product. Higher sampling rates,  resolution, lower THD etc. means nothing if it doesn't sound right or was poorly designed.

Just a thought

Mariusz   

[CSI]

Considering old vs. new technology in general, think about this: Fifty years ago mfgs. began rapidly converting from "old" tube technology to solid state. Transistors were obviously superior in every way and tubes were dead, dead, dead. Of course, most audiophiles could hear the enormous step backward that early SS stuff made but the "new" prevailed in the market place. It took a long time before SS amps began to sound good. In spite of decades of SS refinement there are more tube mfgs. today than ever before. Why? Because there is something about this "obsolete" technology that can often get closer to the music than anything else.
Also, consider switching amp technology. There are brilliant and not so good examples of this relatively new approach. It is green and efficient and very linear. You'd expect "old" class AB and A configurations to be obsolete soon. Want to bet they won't still be around (and preferred by some) fifty years from now?

Elsewhere on this forum Bruno Putzeys - one of the leading Class D amp designers - says he doesn't believe in the inherent superiority of any technology (Class D, AB, A, tube, etc.). He thinks it is nonsense. In his opinion it is all in the execution. He should know.

To paraphrase the old song, "It aint what you do it's the way what you do it".

IMHO, and based on my own experience, if you are faced with a trade off between "musicality" (whatever that means to your ears) and missing out on some technical artifact or the other (a little more detail, airier highs) that comes at the expense of the music - go with the music. You can live without the "audio parlor tricks" (to quote the late John Potis) if the gear puts you more directly in touch with the musicians.

[wilsynet]

And I stand corrected about NOS . I think that in this case, btw, NOS which stands for New Old Stock is also relevant, because if I'm not mistaken this is what Isabellina has - new chips which come from an old stock.

Are you guys saying that in the last decade and a half, the digital realm technological advancements did not improve our listening experience?

For the record, not everything about the MSB is newer than the Isabellina.  For example, checking out the MSB website, I see there's no USB input.  Are you saying after more than 20 years there have been no improvements in digital audio input technology?  Why is MSB using 20+ year old SPDIF coaxial input when it is well recognized that USB is better?

The "NOS" in "NOS DAC" stands for non-oversampling.  It also happens to be true that Vince is using new old stock DAC chips, but that's incidental.  NOS is a type of DAC, and Vince is using the appropriate vocabulary to appropriately label the kind of DAC he's implemented and selling.

No, we're not saying that in 20 years there have been no advancements.  However, many of those advancements have been in oversampling and upsampling as that's what the mainstream is mainly interested in: oversampling and upsampling.  A lot of people like the sound of oversampling and upsampling DACs, and if that's the kind of sound that you like, no one here will tell you that your ears are wrong.  System synergy and personal preference play large part, indeed, the most important parts in component selection.

There have also been advancements in NOS DACs.  For example, a state of the art modern NOS DAC like the Isabellina or the Wavelength Cosecant are both likely better than a NOS DAC made 10 years ago.

Oversampling versus non-oversampling isn't a better/worse/newer/older thing.  It's really a preference thing.  And if your ears don't like the Isabellina, then don't buy it.  By all means audition the MSB DAC; it might sound amazing and you might like it better than the Isabellina.  You might even like it loads better than the Isabellina in your system.  And if you do, no one here will tell you that you're wrong.

Many of us here happen to like the Isabellina more than many oversampling DACs that we've ever heard, but that's a matter of preference and we recognize it for what it is.  There are some people who continue to own both oversampling and non-oversampling DACs and prefer one over the other depending on music, system, and mood.

Personally, I like oversampling DACs.  I just can't listen to one for more than 20 minutes without significant listener fatigue.

[jrebman]

I'm going to take a stab at this from another, slightly different angle.  I think the essence of the question that matanoosh is asking is why use an old NOS chip instead of a newer one with newer technology?

Well, as has already been said, but only really a minor point, is that newer isn't always better.  Would you have rather have had a 1984 or 1964 Corvette? A 1978 Cobra or 1968?

I believe the real question here is if the older NOS dac technology is superior, why is it going out of production?  My answer to that is that the R2R xconversion technique is expensive both to produce and to work with.  R2R to be done well, requires very precise manufacturing, but also separate calibration process such as laser trimming of the individual resistors in the ladder network.  Time consuming, and lots of room for error, and that translates into lower yields.

It is also expensive to implement in a finished product as much of the performance is going to come from the output driver.  It's one thing for a hobbyist to build a great output section for an R2R dac chip where they have the time to make a zillion adjustments and measure and listen as they go, adjusting the power supply characteristics as well for both steady state and dynamic (impulse response) conditions.  It's entirely another thing to come up with a design that works well with the tolerance variations present in bulk ordered components.  Building one that sounds good is easy; building a thousand of them is what separates the men from the boys.

So, a technology that's more time consuming (read, expensive) to produce and with lower manufacturing yields, coupled with being more time consuming to work with at the design phase, and overall lower market demand as a result of the "newer is always better" mindset that marketeers have most people accepting without question, and you have the reason why production is coming to a halt on the R2R technology chips.

Are they the best?  Isn't OS better in every way? My take is that they both do things very well, and make compromises in some areas as well.  For my ears and my tastes, NOS R2R just sounds really natural, and I can live with the areas where it is limited compared to OS technology.  In the case of the Isabellina (and specifically the Isabellina as it has no other sonic influences and stands on it's own merit) I've never heard a dac that I like more.

Being a blind person I often conjure up images of various things as I'm listening to music, whether it's Yo-Yo Ma wrapped in a passionate embrace with his cello, to the exclusion of everything else in the conscious world, to the image of a record spinning on a turntable with the rock steady speed and the delicately balanced needle riding in the groove.  The Isabellina makes these images extremely real to me.  I very often, while listening to the Isabellina, believe that if I open my eyes and look across the room at the audio rack, that I'd see a nice TT sitting there and playing a nice piece of very clean vinyl.

When my system is done being configured, my only two sources will be the RWA dac and a nice, vintage Akai R2R deck.  I really can forego the expense and inconvenience (to me) of the whole vinyl playback rig (which I can't afford anyway.)

So, I hope I answered your question and that the angle I took on why, if these R2R chips are so good and musical, why are they out of production, question, is what you were after.

-- Jim

[wilsynet]

Jim,

An excellent and very informative post.  Thank you.

Wilson

[matanoosh]

Guys,
You're all fantastisc.
Jim, your response is a huge eye-opener. I appreciate the time you invested in writing such a thorough answer to a simply question.
Just one anacdote regarding the boys and men - I got a friend whom we can both classify as a "boy" in this regard - he made a  NOS (non over sampling, I know! ) DAC which sounds very musical and interesting. He wants $500 for it. Gotta be honest with you, though, it doesn't even come close to the Isabellina.

So if I'm trying to sum up your argument in a single sentence, you're saying that technological advancements in this field were mostly made not from sound quality considerations, and top of that R2R technology is primitive only in its low cost effectiveness, but when implemented correctly it does the job equally well, if not better?

[wilsynet]

If you're looking for a definitive statement of truth, I don't think there is one.  So "better or equally well" is not how I'd phrase it.  "Better" is a matter of opinion as NOS does some things better and some things worse.  Some people dislike NOS DACs, other people dislike oversampling DACs, and I won't criticize anyone for having a preference.

What I can say is that the Isabellina does lots of things very well indeed and I don't miss oversampling at all.

[kitten]

The Isabella should accept what it's given up to 96 via USB or 192 via S/PDIF so anyone using a computer to stream music can alter the sample rate using free software, e.g., JRiver. Same with DSP equalisation which is why I'd say the Isabella also doesn't need the added expense of tone controls for those 5 percent of recordings we all seem to have that are unlistenable.

Upsampling into the Isabella to 16/88.2 from 16/44.1 to my ears might have sounded a bit different but I couldn't say it was better, so for now am leaving everything at the native 16/44.1, i.e., I'm listening to exactly what was actually encoded on the CD, which sort of makes sense to me.

Anyone else tried this?

[Freo-1]

Just a couple of thoughts:

I own an 80's Luxman D405 CD player, with a NOS DAC. I really like the sound of this old warhorse,  and with some music, it seems to work better than my Denon 5910. The purpose of oversampling is to make the output signal more analog like, smooth out the waveform, if you will.  Although oversampling does achieve this objective, the oversampling can wind up altering the signal slightly (not always for the better).

Now, if one plays a SACD/DVD audio on the Denon, it kicks ass over the CD version of the same performance (by a LOT!).

[Mariusz]

Like I said, pick your poison and what sounds best for you in your system.
Subject is drowning into the abbys............easily predictable.

[wilsynet]

Engineer extraordinaire Steve Nugent just posted this about NOS DACs over in another thread:

http://www.audiocircle.com/index.php?topic=63530.msg576360#msg576360

[dspringham]

Wilson,

Regarding Steve's post that you alluded to above, would iTunes running on Mac via USB output be considered a "low jitter source"?

If so, then Steve seems to agree that the "simple path" NOS USB DACS perform very well indeed.

Dave

[Crimson]

Wilson,

Regarding Steve's post that you alluded to above, would iTunes running on Mac via USB output be considered a "low jitter source"?

If so, then Steve seems to agree that the "simple path" NOS USB DACS perform very well indeed.

Dave

If using asynchronous mode or a reclocker, yes.