The great digital debate

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audioengr

Re: The great digital debate
« Reply #40 on: 23 Oct 2007, 02:15 am »
300 pSec is low? Add to that..........say....at least 200 pSec for a typical "modern" Crystal RX chip, and that is around 0.5 nSec.

Nope......that is not low. Sorry, dude........

acd843........when are you going to get past this obsession of yours that inaudible distortion and noise are the only qualities to judge sonics by?

Do you really listen to the music, or just read the spec sheet?

Speaking of specs............someone has pointed out to me that there is a controversy as to whether some of the parts actually work in one of those. Supposedly.......someone opened one up, disabled some of the trick circuitry, and measured its performance. Supposedly.........the measurements stayed the same. No, I don't know what lunatic forum that was on, but wouldn't it be funny if that was the real case?

Point being: you can't always believe what manufacturers say. Even us!

The guys who write the marketing hyperbole like to lay it on the offbeat humour a bit much even for my taste.

Pat

I agree with Pat.  These jitter specs are never completely accurate, and usually only quote the jitter from a single part, usually from the spec-sheet of the oscillator itself, not what is measured in the actual system.  This is usually orders of magnitude worse.

I have devoted the last 5 years to reducing jitter to inaudible levels.  Each time I believe I have reached this goal, I product yet another device with even lower jitter and my listeners and customers report that they can plainly hear the improvement.  I have never done any formal listening tests etc.., but I have to believe that sub-nanosecond jitter is definitely audible in a resolving, low-noise system, depending on the spectra.

Steve N.

audioengr

Re: Good grief......
« Reply #41 on: 23 Oct 2007, 02:20 am »
There is no such thing as an absolutely transparent piece of electronics. Never has been, never will be. All will have a sonic signature, however small (or large!) as it may be.

As Charles Hansen of Ayre said to someone recently, on some other forum:

"You must be new at this."

I think it fits well here.

Time to watch football...........

Pat

Again, I agree with Pat.  If you believe that electronics is anywhere near perfection, you have not heard enough electronics yet.  Measurements and specs are still in the dark ages IMO.  There are still no definitive methods to characterize phase shift, group delay, and most important; dynamic response.  The closest thing we have is a free-running square-wave at 1kHz and one at 20kHz.  Not even remotely sufficient to properly characterize audio electronics.  Frequency response is only the tip of the iceberg in characterizing any audio component.

Jitter measurement is just as bad.  This is a non-trivial measurement that is usually trivialized.

Steve N.
« Last Edit: 23 Oct 2007, 02:31 am by audioengr »

audioengr

Re: The great digital debate
« Reply #42 on: 23 Oct 2007, 02:24 am »
I read that a while ago when I was obsessed with finding the DAC that best reduced jitter. Then I saw the wood for the trees...jitter results in distortion. Distortion is easily tested, the DAC with the lowest distortion, by nature, has best mitigated the effects of distortion. You can either get caught up in the details or understand the big picture. Nugent has a lucrative agenda running and as he is a believer in crystals so I can't really see anything he says as legit.

You of course have the right to your opinion.  I have a backlog of about 4 months of customers, so I really dont need any order from you.  If my low-jitter solutions were all bullshit, do you really think that I would have a backlog of 12-20 weeks for several years now?

BTW, I dont spend a penny on advertising.  It's all word of mouth.

Steve Nugent

art

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Some debate, eh?
« Reply #43 on: 23 Oct 2007, 03:20 am »
Steve:

Thanks for the words of support. Not sure how they managed to drag you in,  but "it happens".

(Apologies to Forrest Gump.)

Pat

mfsoa

Re: The great digital debate
« Reply #44 on: 23 Oct 2007, 03:25 am »
Someone correct me if I'm wrong ('cause I probably am) but don't analog switching amps (like the RWA Sig 30's acd has) have relatively high distortion values and require special filters/test setups on the test equipment to yield results comparable to "conventional" gear. Maybe it was s/n ratio at high frequencies? What about the appearance of a 10khz square wave - Doesn't that show a huge amount of ripple that's not in the input waveform - uh oh, that would be distortion then.

Sorry if I lump RWA in with other switchers if that wasn't appropriate. I'm sure Vinnies products are first-rate.

But I seem to remember that based on conventional measurements these types of amps really show poorly in some of the measured performance parameters. (Don't tell acd this - he'll have to sell his amps because now they won't sound as good as he thought they did!)







 

miklorsmith

Re: The great digital debate
« Reply #45 on: 23 Oct 2007, 03:39 am »
I think one of the British mags measured one of the RWA amps and it actually measured pretty well.  Oh, now I might need to sell mine.   :D

This discussion is worthless.  Frankly, Mr. Prickles should go on over to AH where they'll caudle him and try to nurture him back from his perilous captivity by Those Tube Loving Audiophiles.

art

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It is not "distortion"........
« Reply #46 on: 23 Oct 2007, 03:41 am »
Class D amps will have a fair amount of the carrier frequency on the output; whether they are the clocked or self-oscillating types. This RF carrier can overload the front-end of wideband equipment typically used these days to measure distortion.

But back in the good ol' days (when we only had "conventional" amps), you frequently used a notch filter in front to get accurate measurements. Especially if you want to get the higher order stuff (like the 7th) which might be down in the noise floor without notching techniques.

So, it is not uncommon to stick some sort of filter in a distortion measurement.

Pat

audioengr

Re: The great digital debate
« Reply #47 on: 23 Oct 2007, 05:28 am »
Someone correct me if I'm wrong ('cause I probably am) but don't analog switching amps (like the RWA Sig 30's acd has) have relatively high distortion values and require special filters/test setups on the test equipment to yield results comparable to "conventional" gear. Maybe it was s/n ratio at high frequencies? What about the appearance of a 10khz square wave - Doesn't that show a huge amount of ripple that's not in the input waveform - uh oh, that would be distortion then.

Sorry if I lump RWA in with other switchers if that wasn't appropriate. I'm sure Vinnies products are first-rate.

But I seem to remember that based on conventional measurements these types of amps really show poorly in some of the measured performance parameters. (Don't tell acd this - he'll have to sell his amps because now they won't sound as good as he thought they did!) 

Most digital amps switch in the 200KHz-1MHz range, well above audible frequencies.  It is the modulation techniques that usually introduce non-linearities.  Every "module" available these days uses a different modulation technique.  Some are more musical than others I have found.  One limitation with switching amps is that they usually use a small number of devices to do the switching and drive the outputs.  This means relatively high output impedance, and the resultant difficulty driving difficult speaker loads.  The Nuforce for instance has excellent dynamic response and HF extension, but is a bit flabby in the bass, depending on the speakers connected.

There is usually some RF at the outputs too.  This is filtered with both series inductance and parallel capacitance, and sometimes even resonant filters, which can work really well.  The problem with resonant filters is that the components must be of high tolerance, the caps and inductors.  I have seen commercial designs (I have modded a few of them) that worked really well and filtered well on the bench, but the production version had a lot of RF on the outputs.  I stopped modding these because of the high levels of RF inside the hot box when I was working on it.  Like being inside a microwave oven....

In theory, the digital switching amp can be faster and have a more perfect response than an analog amp, but the actual implementations vary a lot.  The other advantage is that the audio can be kept in the digital domain until the output to the speakers, such as the parts from TI.  This minimizes distortion and noise.  There are a few receivers from Sony and Panasonic based on these parts that are excellent.

Steve N.

acd483

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Re: The great digital debate
« Reply #48 on: 23 Oct 2007, 01:20 pm »
I read that a while ago when I was obsessed with finding the DAC that best reduced jitter. Then I saw the wood for the trees...jitter results in distortion. Distortion is easily tested, the DAC with the lowest distortion, by nature, has best mitigated the effects of distortion. You can either get caught up in the details or understand the big picture. Nugent has a lucrative agenda running and as he is a believer in crystals so I can't really see anything he says as legit.

Of course what you are saying is that his I2s Off Ramp/modded Dac-1 doesn't have lower distortion than the stock S/PDIF Dac-1.

Since he has claimed that it does, you must be calling Steve a liar.



Steve's modified DAC-1 may well have lower distortion than Benchmark's, but as the Benchmark's distortion is impossible to hear, the "improvement" is of no practical value.

acd483

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Re: The great digital debate
« Reply #49 on: 23 Oct 2007, 01:23 pm »
I read that a while ago when I was obsessed with finding the DAC that best reduced jitter. Then I saw the wood for the trees...jitter results in distortion. Distortion is easily tested, the DAC with the lowest distortion, by nature, has best mitigated the effects of distortion. You can either get caught up in the details or understand the big picture. Nugent has a lucrative agenda running and as he is a believer in crystals so I can't really see anything he says as legit.

You of course have the right to your opinion.  I have a backlog of about 4 months of customers, so I really dont need any order from you.  If my low-jitter solutions were all bullshit, do you really think that I would have a backlog of 12-20 weeks for several years now?

BTW, I dont spend a penny on advertising.  It's all word of mouth.

Steve Nugent

I congratulate you on your success.

Marbles

Re: The great digital debate
« Reply #50 on: 23 Oct 2007, 01:28 pm »

Steve's modified DAC-1 may well have lower distortion than Benchmark's, but as the Benchmark's distortion is impossible to hear, the "improvement" is of no practical value.

And you know this how?

Do you think that they both sound identical?

doug s.

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Re: The great digital debate
« Reply #51 on: 23 Oct 2007, 01:51 pm »
he would have to have auditioned them in order top know, so he's obviously blowing smoke out of one of his orifices.

which is why he also refuses to answer any comments i have made about the mytek - even tho i have read several comments from people who have heard both & preferred the mytek, & i have read of no one who prefers the benchmark, (siimilar story for the $1k lavry dac), acd483 has no comment.

now, if acd483 would say that there may be an audible difference, but he doesn't think it worth the cost, i could understand.  i might even agree.   :wink:

doug s.


Steve's modified DAC-1 may well have lower distortion than Benchmark's, but as the Benchmark's distortion is impossible to hear, the "improvement" is of no practical value.

And you know this how?

Do you think that they both sound identical?

Marbles

Re: The great digital debate
« Reply #52 on: 23 Oct 2007, 01:54 pm »

now, if acd483 would say that there may be an audible difference, but he doesn't think it worth the cost, i could understand. 
doug s.



Me too.

darrenyeats

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Re: The great digital debate
« Reply #53 on: 23 Oct 2007, 03:41 pm »

You of course have the right to your opinion.  I have a backlog of about 4 months of customers, so I really dont need any order from you.  If my low-jitter solutions were all bullshit, do you really think that I would have a backlog of 12-20 weeks for several years now?

BTW, I dont spend a penny on advertising.  It's all word of mouth.

Steve Nugent

I congratulate you on your success.

And let's not forget Bose and Radio Shack's success too. Congratulations everyone.

No I'm not impressed by the sales argument. On the other hand, certainly I DO applaud Steve's approach that is based on measurement (reducing jitter in this example). When it comes to product development surely measurement and blind testing must be important guides. I know you can never be completely objective - because it's always your ears and your taste - but these approaches will help.
Darren

audioengr

Re: The great digital debate
« Reply #54 on: 23 Oct 2007, 06:04 pm »
I read that a while ago when I was obsessed with finding the DAC that best reduced jitter. Then I saw the wood for the trees...jitter results in distortion. Distortion is easily tested, the DAC with the lowest distortion, by nature, has best mitigated the effects of distortion. You can either get caught up in the details or understand the big picture. Nugent has a lucrative agenda running and as he is a believer in crystals so I can't really see anything he says as legit.

Of course what you are saying is that his I2s Off Ramp/modded Dac-1 doesn't have lower distortion than the stock S/PDIF Dac-1.

Since he has claimed that it does, you must be calling Steve a liar.



Steve's modified DAC-1 may well have lower distortion than Benchmark's, but as the Benchmark's distortion is impossible to hear, the "improvement" is of no practical value.

I dont know about you, but I dont believe everything I read.

Steve N.

acd483

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Re: The great digital debate
« Reply #55 on: 23 Oct 2007, 11:58 pm »
he would have to have auditioned them in order top know, so he's obviously blowing smoke out of one of his orifices.

which is why he also refuses to answer any comments i have made about the mytek - even tho i have read several comments from people who have heard both & preferred the mytek, & i have read of no one who prefers the benchmark, (siimilar story for the $1k lavry dac), acd483 has no comment.

now, if acd483 would say that there may be an audible difference, but he doesn't think it worth the cost, i could understand.  i might even agree.   :wink:

doug s.

Here's what I find amusing from you all who claim there are discernable differences among top quality DACs. Both manufacturers; Benchmark and Mytek proudly state that their DACs are "transparent". Here follow the juicy bits:

From the Benchmark site:
The DAC1 USB is designed for maximum transparency and is well suited for critical playback in studio control rooms, mastering rooms, and high-end audiophile applications.

From the Mytek website:
"Users choose Mytek 8X96 converters primarily for their outstanding sound quality. The sound of Mytek converters can be described as "transparent". We design our converters to be as faithful to the signal as possible, rather than follow philosophy of some other manufacturers who offer "analog" or "tube" sounding converters. Mytek converters are closest to a straight wire, which is especially evident when used at full 24/96 resolution."

Now, the Benchmark has a SNR of 116db while the Mytek 120db. The Total Harmonic Distortion of both is -107db. So, if these numbers point to transparency, and both manufacturers claim transparency, where is the audible difference? I expect the chattering horde to come on claiming those aren't the only determining factors in the way electronics produce sound. Well, tell me what does! As we all would agree, it's the distortion that tubes produce which attracts people or is it their intoxicating glow?

As for the previous posts trying to take apart my current system, go ahead! I don't claim it's infallible. In fact, I can't wait to get rid of the Constantine DAC. As for the Sig 30, it's an excellent piece of equipment and Vinnie is a stand up guy (and yes, I've met him).

In the end, I wonder what Benchmark has to say about Steve Nugent modifying its DAC-1 and charging as much as four times the original price? It must be THAT much more transparent, but what do I know, I haven't gone out and spent $4500 to find out.

doug s.

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Re: The great digital debate
« Reply #56 on: 24 Oct 2007, 01:58 am »
Here's what I find amusing from you all who claim there are discernable differences among top quality DACs. Both manufacturers; Benchmark and Mytek proudly state that their DACs are "transparent". Here follow the juicy bits:

From the Benchmark site:
The DAC1 USB is designed for maximum transparency and is well suited for critical playback in studio control rooms, mastering rooms, and high-end audiophile applications.

From the Mytek website:
"Users choose Mytek 8X96 converters primarily for their outstanding sound quality. The sound of Mytek converters can be described as "transparent". We design our converters to be as faithful to the signal as possible, rather than follow philosophy of some other manufacturers who offer "analog" or "tube" sounding converters. Mytek converters are closest to a straight wire, which is especially evident when used at full 24/96 resolution."

Now, the Benchmark has a SNR of 116db while the Mytek 120db. The Total Harmonic Distortion of both is -107db. So, if these numbers point to transparency, and both manufacturers claim transparency, where is the audible difference?
so, i guess the folks who like the mytek better than the benchmark must really be falling for the placebo effect?  they like the much spendier dac?  (even tho they are the same price?)  they like the smashing looks of the mytek?  (even tho it's butt-ugly?)   :scratch:  or, maybe they like the sound of the mytek better than the benchmark, even tho they sound the same!  cuz, obviously - if you don't know why there's an audible difference, it means there is no audible difference, even if they do sound different!   :lol:

I expect the chattering horde to come on claiming those aren't the only determining factors in the way electronics produce sound. Well, tell me what does!
better yet, why don't you tell us?  cuz, that's the $64,000 question.  answer it & it will make you a rich man.  obviously, something is making folks prefer the mytek over the benchmark.   8)


In fact, I can't wait to get rid of the Constantine DAC.
why bother?  the constantine has distortion so low that it's impossible to hear; you won't be able to hear any improvemant at all, w/a dac that is three times the cost of your constantine - you will yust be throwing your money away!!!   specifications mean everything!!!  as long as a dac has distortion so low it's impossible to hear, it is as good as it gets - acd483 said so himself, & he knows everything!!! :green:

doug s.

art

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Re: The great digital debate
« Reply #57 on: 24 Oct 2007, 02:40 am »
Now, the Benchmark has a SNR of 116db while the Mytek 120db. The Total Harmonic Distortion of both is -107db. So, if these numbers point to transparency, and both manufacturers claim transparency, where is the audible difference?

And your point is? They can (and in fact, do) claim anything that they want. Does not make it the truth. Just marketing copy.

Quote
I expect the chattering horde to come on claiming those aren't the only determining factors in the way electronics produce sound. Well, tell me what does!

Why? You are clearly as close-minded as they come.

Good luck, bub........you are going to need it someday.

Pat

Marbles

Re: The great digital debate
« Reply #58 on: 24 Oct 2007, 02:45 am »
Guys, let's not pound on acd483 anymore.

Actually I'm jealous of his ability to know how a particular component will sound without actually listening to it.  It's a very rare individual that possesses this ability.  Wish I did! 

TomS

Re: The great digital debate
« Reply #59 on: 24 Oct 2007, 02:52 am »
Guys, let's not pound on acd483 anymore.

Actually I'm jealous of his ability to know how a particular component will sound without actually listening to it.  It's a very rare individual that possesses this ability.  Wish I did! 
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