[muralman1]

Jim, that was just wonderful. You are stating a truth that I have been clumsily trying to get across. Although I have heard fairly good OS based systems, my NOS system is simply more detailed, smooth, deep, fluid, and foot tapping. There really has been no contest when fed into my Apogee Scintilla system.

I don't know the manufacturing realities, like you have explained Jim. My science education tells me that the very small and nearly infinitely complex music signal cannot be successfully altered without damaging it.

[wilsynet]

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

Owing to the wide variety of PC laptops and desktops out there, there's likely a lot of variability with PCs.  It explains why some people say their PC laptop is great, and others say there's clicks and pops, and still others say once they switched to a Mac, life was better.

Someone quoted a Wavelength dealer in AudioCircle awhile ago saying that the async USB mode in the Wavelength DACs made a big difference with his PC, and a very small difference in his Mac.  So my guess is that compared to many other transports out there the Mac is comparatively low jitter.

I've never measured the jitter on the USB streaming audio output of my Mac, I'm just gathering odds and ends from posts about USB audio over the past few years.

[matanoosh]

could you please elaborate on asynchronous vs. synchronous and perhaps suggest ways to convert one method to the other in order to improve sound quality?

(I'm sorry if the question is stupid; I just don't know what the term means. )

[Crimson]

could you please elaborate on asynchronous vs. synchronous and perhaps suggest ways to convert one method to the other in order to improve sound quality?

(I'm sorry if the question is stupid; I just don't know what the term means. )

Most USB dacs use what is referred to as adaptive mode i.e. the computer controls the flow of data from computer to dac. In this mode, there are clocking discrepancies (which translate to jitter) because a USB bus runs at its own frequency which is not a multiple of PCM at any bit rate or sampling frequency. Asynchronous mode, on the other hand, means the dac controls the flow of data from the computer based on its own master clock, effectively all but eliminating any timing errors. Conversion between the two types of transfer is not possible without recoding.

[wilsynet]

It's not just about async mode, just as it isn't just about DAC chips and whether something is oversampling or non-oversampling.  Clean power is important, and as per Steve Nugent's post, so is the simplicyt of signal paths and the output stage.  Those last things are things that Vinnie reputedly does very well and it's nice to see Steve modify his thinking around some of this.

I'm delighted with my Isabella/Isabellina, and after auditioning more than half a dozen DACs over the past 2 years, I'm glad to have gotten off the merry-go-round.  Thank goodness for Red Wine Audio.

Vinnie doesn't believe his DAC is particularly sensitive to jitter and he has a number of posts here explaining why.  I won't argue with him because his DAC is plain and simply incredible.  Only time and a few more generations of DACs will settle the argument.  Vinnie, Steve, and Gordon, the people who are in my mind the leaders of reference quality USB DACs, they'll all make improvements to their products over the next few years.  In the mean time, there is this incredible DAC that I get to listen to every day.

I see the wisdom of Mariusz now.  The subject is drowning.  The Isabellina is made with a mix of bleeding edge technology as well as what's tried and true.  I doubt there's much more that I can add here.

[jrebman]

Matanoosh,

As Wilson said, there is no real definitive right or wrong answer.  My point was that not only can we assume that newer is better, but there are other forces at work that make things go out of production, and one shouldn't be overly concerned about whether or not the technology is older, only how it sounds when implemented correctly.

There are plenty of terrible, and plenty of incredible tube amps in the world, and likewise, SS, I just prefer tubes myself, but that's what I grew up with.

Thanks all others for the kind feedback as well.

-- Jim

[Vinnie R.]

All,

Great thread!  I want to thank all of you who have already posted - excellent discussion!

Hi matanoosh,

Welcome to audiocircle and the RWA forum!

After reading through all the posts in this thread (catching up with it since I have been away at the CES show), I think everyone did a great job covering the heart of why people love our Isabellina dac - because they LOVE the music it recreates in their system! 

I'll use the good ol' "making a stew" analogy - a chef will use the ingredients that give his stew his signature taste.  For us, this includes:

- A 16-bit, non-oversampling dac (yes, this chip is also "new old stock" because it is no longer in production)
- A Class-A, zero feedback discrete FET output stage (no opamps, no feedback, no passive resistor I/V conversion)
- SLA battery power, with linear regulation for the digital and analog sections
- USB direct to I2S conversion
- A handful of other tricks that complete the recipe and make the Isabellina unique sounding.

Changing any of the ingredients changes the resulting sound (or what you would taste if it was stew).

As mentioned on our website, the Isabellina was designed to recreate music from digital media that closely matches the finest sonic qualities of analog sources such as the richness of tone, extraordinary timing/pacing, and an effortless presentation of the music.  Unlike many dacs available today, which boast impressive specs but sound to us to be flawed with an analytical, cold and sterile ("digital") sound, the Isabellina offers a natural and emotionally involving musical presentation. 

I could not achieve this type of sound using the newer dac chips (I've heard and played with many of them - they do NOT offer the sound that I was looking to offer).  Does this make the Isabellina better than other dacs? - NO, not at all.  As mentioned above, it is a matter of taste.  There is no right or wrong - it is all about how the music connects with you.  We can talk about jitter, oversampling, the latest dac chips with the latest and greatest specs, etc. etc. all day and night.  All of this really does not matter to the listener if they do not get connected to the music using our products.

As mentioned above, tubes are an old technology (much older than nos dacs!) - if people were hesitant to try tube-based products simply because they are old technology, we would not see so many tube amps being designed and sold every year.  There are many tube lovers out there - Why?  Again - because they love the music that certain tube designs recreate and are not concerned about the specs or the age of the technoloogy.  They trust their ears, they know their tastes, and buy what makes them happy.

Thanks again for the great discussion and excellent posts! (and trying to keep this thread on topic)

Vinnie

[matanoosh]

Vinnie,
So when are you shipping out my DAC?

Btw, I read about the slightly problematic issue of creating an accurate clock via USB. Do you have any suggestions on how I can improve the computer's USB clock output to make it more accurate and hopefully increase the sound quality? Or is it all nonsense?

[Vinnie R.]

Vinnie,
So when are you shipping out my DAC?

Btw, I read about the slightly problematic issue of creating an accurate clock via USB. Do you have any suggestions on how I can improve the computer's USB clock output to make it more accurate and hopefully increase the sound quality? Or is it all nonsense?

Hi Matanoosh,

The USB signal from your computer is fine - just connect it to the Isabellina and enjoy the music! 

Best regards,

Vinnie

[matanoosh]

I can imagine how annoying those seemingly "savvy" (or savvy wannabe's ) customers can be (such as myself ).
I'm simply trying to maximize the Isabellina feed. It still amazes me how much improvement i got simply by changing my player's output from 16bit to 24bit, even on 16/44.1hz files.
In the Isabellina's case, at least, it made a huge difference.

So, first thing Monday morning I'll nag my local distributor about my newly ordered DAC. I'll ask him if he called the manufacturer and made the ordrer .

Vinnie, thanks for the kind, patient phone support. I can't wait to get my Isabellina already:)

[Vinnie R.]

So, first thing Monday morning I'll nag my local distributor about my newly ordered DAC. I'll ask him if he called the manufacturer and made the ordrer .

Vinnie, thanks for the kind, patient phone support. I can't wait to get my Isabellina already:)

Hi Matanoosh,

You are very welcome and we are currently working on building a new batch of Isabellina dacs -  aa
We should be able to ship in just a couple of weeks...

Best wishes,

Vinnie

[Marco Prozzo]

I've gone through quite a variety of DACs and digital front ends, and most (not all) of those I like best have been NOS.  I tried the well respected and reviewed Benchmark, which I think is an upsampling DAC, twice (early version and USB version) in several systems and could not get it to sound good to my ears (always strident in the highs).  That said, I had the pleasure of hearing Vinnies DAC and his amps, at his room at CES and was very impressed with the sound.  It was non-fatiguing, natural and easy to listen to and engaging.  I found myself sitting there longer than many rooms.  This seems to be a commonality in my own response to NOS DACs - they just seem more relaxed and easy to listen to.  I'll let others with more technical know-how argue and knit-pick as to why - I tend to rely on my ears. I do just instinctively like that Vinnie has chosen to go direct from USB to l2S which I believe is a native 'language' requiring no additional conversion like an S/PDIF input (someone correct me if I'm wrong or not describing that well). 

Bottom line, it sounds great!  Nice to finally meet you, Vinnie.  I hope Peter made it to your room to hear the 70.2s in action.   

[Eadron]

Vinnie, thanks for the kind, patient phone support. I can't wait to get my Isabellina already:)

Vinnie is the man  ! matanoosh, I think strongly that you made the very right decision  aa..

Have fun!

jouni

[Vinnie R.]

Hi Marco,

Welcome to Audiocircle and the RWA forum!

I had the pleasure of hearing Vinnies DAC and his amps, at his room at CES and was very impressed with the sound.  It was non-fatiguing, natural and easy to listen to and engaging.  I found myself sitting there longer than many rooms.  This seems to be a commonality in my own response to NOS DACs - they just seem more relaxed and easy to listen to.

I couldn't agree with you more!     

I enjoyed meeting you, and thank you for coming back to our room and listening (with the WLM Sonata, and the 70.2s!  ).

I must also add that you do very fine photography and graphic design work: www.marcoprozzo.com --- I'm sure Modwright and Wright Sound must be extremely pleased! 


Hi Jouni,

Thank you.  If matanoosh listened with his own ears and fell in love with the Isabellina sound (which it sure sounds like he did!), then we know he made the right decision and will be a proud owner!     Thanks again!

Best regards,

Vinnie