ANNOUNCING THE NEW AVA VISION DAC ! ! !

turkey · « **Reply #180 on:** 21 Jan 2010, 05:34 pm »

Quote from: Wayner on 21 Jan 2010, 04:51 pm

The frequency response of the DAC and power output is ruler flat at all volumes.

Which ones don't have ruler flat FR?

rajacat · « **Reply #181 on:** 21 Jan 2010, 05:38 pm »

Quote from: turkey on 21 Jan 2010, 05:34 pm

Which ones don't have ruler flat FR?

If two DACs have ruler flat freq. responses what would be the reason that they might not sound identical?

-Roy

oneinthepipe · « **Reply #182 on:** 21 Jan 2010, 05:50 pm »

Quote from: rajacat on 21 Jan 2010, 05:38 pm

If two DACs have ruler flat freq. responses what would be the reason that they might not sound identical?

-Roy

Devices abilities to simultaneously reproduce multiple frequencies with multiple volumes and multiple speeds. Different devices have different sonic characteristics. Different opamps produce a different sound. Different tubes produce a different sound.

srb · « **Reply #183 on:** 21 Jan 2010, 05:52 pm »

A flat frequency response might not necessarily reveal components of the audio signal such as:

1. Random noise and harmonic ailasing that may or may not be removed or tamed with filtering circuitry

2. Mistiming and smearing of the audio signal due to jitter

Steve

turkey · « **Reply #184 on:** 21 Jan 2010, 06:01 pm »

Quote from: srb on 21 Jan 2010, 05:52 pm

A flat frequency response might not necessarily reveal components of the audio signal such as:

1. Random noise and harmonic ailasing that may or may not be removed or tamed with filtering circuitry

2. Mistiming and smearing of the audio signal due to jitter

Steve

I don't think I've seen any DACs with problem #1 at audible levels. #2 has never been shown to be an audible problem for typical DACs and CD players.

srb · « **Reply #185 on:** 21 Jan 2010, 06:02 pm »

Quote from: turkey on 21 Jan 2010, 06:01 pm

I don't think I've seen any DACs with problem #1 at audible levels. #2 has never been shown to be an audible problem for typical DACs and CD players.

Then all DACs with similar frequency response sound the same.

Steve

rajacat · « **Reply #186 on:** 21 Jan 2010, 07:37 pm »

Does the new Vision DAC have a flatter FR than the Insight DAC?

-Roy

Wayner · « **Reply #187 on:** 21 Jan 2010, 08:09 pm »

Lots of folks claim their device has a frequency response of 20-20K. They forget to mention that between 20-250hz, it's down 2 db or there is a 3db rise in the 5K region or that the top end has a risings slope at 12K and drops to -3db at 20K. When you hear such a device, it sounds like someone has fiddled with the tone controls. The balance of sound is skewed.

This is really no different then the things I look for in analog with my vinyl set-up. I look for that balanced sound with lots of air around the recording, then I know that things are set-up right with adjustments like VTF, VTA anti-skating and such. This is also one of the reasons why Frank is bridging the gap between analog and digital playback. He also knows that this is the direction to find the Holy Grail of sound reproduction. Do nothing to the music but amplify it. That is the mission of the DAC, the preamp, the amp, the speakers: Just do as you are told. And the one that is doing the telling is the source material.

Last night I listened to an old Queen CD, A Night at the Opera, starting on track 9 "Love of my LIfe". This CD is from 1991, not any redo. It brought tears to my eyes. The CD never sounded this good. It doesn't take very long to get emotionally involved with the music when it's delivered correctly. The funny thing is, I'm hearing it better then the guy that was mixing the master back in 1975.

Wayner

budyog · « **Reply #188 on:** 21 Jan 2010, 08:22 pm »

Quote from: Wayner on 21 Jan 2010, 08:09 pm

Last night I listened to an old Queen CD, A Night at the Opera, starting on track 9 "Love of my LIfe". This CD is from 1991, not any redo. It brought tears to my eyes. The CD never sounded this good. It doesn't take very long to get emotionally involved with the music when it's delivered correctly. The funny thing is, I'm hearing it better then the guy that was mixing the master back in 1975.

Wayner

Hey Wayner,
Not to sidetrack this thread, but funny you mention "Queen, Night at the Opera"! I just listened to this in its entirety over the weekend on DVD Audio and it was just breathtaking! I haven't listen to this is a couple years. It was so good sounding, I needed more so I then put on "The Game" also on DVD audio. Not quit as good as NATO, but wow! Very powerful! The distinct placement and sound of the individual instruments is so cool!
I was thinking this would be a great vinyl to disc comparison. I would love someone to bring over a good turntable setup and this album and compare them. I feel it would be hard to beat these on DVD audio!

Wayner · « **Reply #189 on:** 21 Jan 2010, 09:12 pm »

Hi Micheal, Have you ever heard Innuendo? It was Freddie's last record and it is also very good. Not sure if it's on DVD as he was dying from AIDS during the recording sessions. The songs have lyrics about the ordeal "I'm going slightly mad" and others have a tale of Freddie's demise. Also out on LP.

Wayner

turkey · « **Reply #190 on:** 21 Jan 2010, 09:21 pm »

Quote from: Wayner on 21 Jan 2010, 08:09 pm

Lots of folks claim their device has a frequency response of 20-20K. They forget to mention that between 20-250hz, it's down 2 db or there is a 3db rise in the 5K region or that the top end has a risings slope at 12K and drops to -3db at 20K. When you hear such a device, it sounds like someone has fiddled with the tone controls. The balance of sound is skewed.

While this is true of speakers and phono cartridges, it is not true of the vast majority of modern SS electronics, including DACs. (It's not true of the better small-signal tube gear either, although tube amps typically have a large enough output impedance so that their FR is squirrelly into a speaker load.)

It's pretty much trivially easy to get flat FR out of modern electronics. If you don't, it's probably because the designer had some screwy ideas, or wanted his stuff to sound "different."

Wayner · « **Reply #191 on:** 21 Jan 2010, 09:29 pm »

My examples are extreme to get my point across, nonetheless, there are differences in designs and execution of the designs. This is caused by the DAC chips themselves, filtering etc. Obviously, the chip set technology is changing and we get to benefit from the evolution, but it is not chip set alone that makes the DAC.

Wayner

budyog · « **Reply #192 on:** 21 Jan 2010, 10:13 pm »

Quote from: Wayner on 21 Jan 2010, 09:12 pm

Hi Micheal, Have you ever heard Innuendo? It was Freddie's last record and it is also very good. Not sure if it's on DVD as he was dying from AIDS during the recording sessions. The songs have lyrics about the ordeal "I'm going slightly mad" and others have a tale of Freddie's demise. Also out on LP.

Wayner

Oh yes, I have that too, I have even seen Queen twice "Live"! Great shows. But "Innuendo" is not the final Queen with Freddie album. The final Queen with Freddie in his very last days is "Made In Heaven". Freddie struggled to get up and get to the studio but when he did, he gave it all he had to do this album. The rest of the band worked around him and his health to complete this album. If you do not have "Made In Heaven", I certainly recommend this album too. Very sad but very good. It has been 19 years already and Freddie lives on!

DSK · « **Reply #193 on:** 21 Jan 2010, 11:33 pm »

Quote from: turkey on 21 Jan 2010, 09:21 pm

While this is true of speakers and phono cartridges, it is not true of the vast majority of modern SS electronics, including DACs. (It's not true of the better small-signal tube gear either, although tube amps typically have a large enough output impedance so that their FR is squirrelly into a speaker load.)

It's pretty much trivially easy to get flat FR out of modern electronics. If you don't, it's probably because the designer had some screwy ideas, or wanted his stuff to sound "different."

Exactly what I was thinking when I read that erroneous post.

Rather than read incorrect reasonings for why a particular component may sound like it does from people who don't really know (this includes myself), I would much rather read what Vision DAC owners are hearing with their ears.

martyo · « **Reply #194 on:** 22 Jan 2010, 10:05 am »

Quote

Rather than read incorrect reasonings for why a particular component may sound like it does from people who don't really know (this includes myself), I would much rather read what Vision DAC owners are hearing with their ears.

Ohhhh, you mean you want listening impressions rather than dogma.

turkey · « **Reply #195 on:** 22 Jan 2010, 04:06 pm »

Quote from: martyo on 22 Jan 2010, 10:05 am

Ohhhh, you mean you want listening impressions rather than dogma.

It's more that when someone says, "I like this better than that," I may not agree with them, but I can't really argue with them liking it better. (Now when they go from that to saying it _is_ better, then I may object.)

What typically bothers me is when someone likes something better and tries to give a scientific explanation for it and they don't make sense. (I'm not really directing this at Wayner. I think maybe he just misspoke or wasn't clear. I'm more concerned with the organized audio voodoo that's so prevalent.)

You see it in the magazines and on the review web sites a lot. Someone will like an amp, and then state that they think the reason it's better is because it uses XYZ brand filter caps in the power supply. They're basically talking out of their backsides. They have no proof that the amp even sounds better, they don't know how it performs in absolute terms, and they don't know that the brand of caps is what makes it better.

So then you see a statement that a DAC is better than others because it has flat FR. Well, that's not an uncommon feature of DACs. Any DAC should have flat FR. If this DAC sounds better than others, there has to be another reason. That's what I was trying to get at.

I suspect that a major motivation for the Vision DAC was that the prior DACs were based on discontinued parts, forcing a new design. The old design _was_ rather long in the tooth, and there was some evidence that the digital part of it wasn't that great.

Nevertheless, I'm sure there are plenty of measured, objective parameters in which the new design is superior to the old. I'm also sure that Frank had solid, objective reasons guiding him and AVA to the result - the Vision DAC.

As for whether it sounds better or not, that's getting into a kind of grey area. Some will say yes, some no, and some won't hear any difference.

I think what I would say is that if you buy a Vision DAC you're getting Frank's excellent customer service and a piece of equipment that will last you for the next couple of decades.

avahifi · « **Reply #196 on:** 22 Jan 2010, 04:18 pm »

Actually I have enough parts on hand for our previous generation DACs to keep building them for another year or so.

The decision to put the Vision DAC into production now was based upon the value of the sonic quality we could offer our customers now, rather than a "oh my God we are running out of parts."

We just made a few thousand dollars worth of parts obsolete here for ourselves to do this

Anyone need a whole lot of NOS DAC parts?

Regards,

Frank Van Alstine

Wayner · « **Reply #197 on:** 22 Jan 2010, 04:22 pm »

Perhaps, as I stated before, my first example was extreme, however, the explanation of the difference in sound from one DAC or another, or even the CD players DAC has not been explained. As an example of this, I can A-B my Sony XA20ES CD player's internal DAC with the Vision DAC and the differences are very obvious, within a few seconds. So, if both DACs have the same ruler flat measured response, as some of you may think, then what is the explanation? I have the same transport driving both DACs yet they are worlds apart in dynamics, frequency response (in linear terms), and air. We have to assume the data stream from the transport section is doing it's job, but down stream, things are different. The Vision DAC has a more solid bass response, the Sony's internal DAC is weak in comparison. If one DACs lower frequency response is weaker then the other DACs, what is the explanation other then the linearity of the DAC chip set or analog section, then one has to assume it to be not ruler flat.

Wayner

avahifi · « **Reply #198 on:** 22 Jan 2010, 04:33 pm »

Wayne, you are probably hearing thermal feedback distortion in your Sony CD player output section.

This will not show up on frequency response tests (most musical differences are very difficult to measure and IHF tests look at only a small sub-set of all the issues).

However what is happening is that the heat generated internally in the active devices by trying to process low frequency signals significantly affects the linearity of the process dynamically. The bass looses power and definition. Actually the effect can extend throughout the audible range. This is quiet easy to observe in a power amp by looking at the output of the voltage amp section trying to drive the current amp section. You can see the feedback loop trying to make a mush like low frequency impossibe correction.

Regards,

Frank Van Alstine

turkey · « **Reply #199 on:** 22 Jan 2010, 04:45 pm »

Quote from: avahifi on 22 Jan 2010, 04:33 pm

Wayne, you are probably hearing thermal feedback distortion in your Sony CD player output section.

This will not show up on frequency response tests (most musical differences are very difficult to measure and IHF tests look at only a small sub-set of all the issues).

However what is happening is that the heat generated internally in the active devices by trying to process low frequency signals significantly affects the linearity of the process dynamically. The bass looses power and definition. Actually the effect can extend throughout the audible range. This is quiet easy to observe in a power amp by looking at the output of the voltage amp section trying to drive the current amp section. You can see the feedback loop trying to make a mush like low frequency impossibe correction.

Regards,

Frank Van Alstine

Could you pursue this at some point? Like maybe have Wayner bring over his CD player and verifying it has problems in this respect?

It would also be interesting if you could have two otherwise identical circuits, with one of them exhibiting this problem, and then listen to them and see what the difference is.

Is the cure as simple as putting a heatsink on some active devices, or choosing devices with higher ratings? Or adding a high-pass filter at the input of the section that's getting into trouble? (The sack of potatoes principle.)