NOS DAC - Marketing BS? - Page 8

Hi Benjamin,

Time domain and frequency domain are not two different things. They are a different way of looking at the same thing. You do not get to choose one over the other.

Jitter is usually viewed form a time stand point, but one can view it from a frequency stand point. A sine wave tone is usually often "viewed" by its frequency and amplitude (like an FFT plot), but one can look at it as a time domain signal (like as a scope).

Take some wave, say a 1KHz square wave, it can be looked at as a sum of harmonics. There is a 3Khz, 5Khz, 7KHz... If you change the amplitude or phase of ANY of the harmonics (frequencies domain alteration), when you look at the time domain (scope picture) the waveform is no longer the original square wave.

Now take say a sine wave (a scope picture). A single sine wave looks like a single tone in frequency domain (say FFT plot). Say you clip the top of it, or do anything to change its shape on the scope. When you look at the frequency domain, you will have more then one tone, the frequency picture changed.

You can not do one without the other. You do not get to choose one or the other.

Jitter decreases accuracy. It decreases the accuracy of the wave shape in the time domain, and it alters the frequency picture as well, such as smear, or adding side bands...

To have time domain transparency, you need low jitter. To have frequency domain transparency you need low jitter.

Once you have good time domain reproduction it is good at any domain. If a DAC is "bad with frequency response", it is also "bad with time response".

Altered frequency response means altered time domain wave shape. Cause and effect should be kept apart. Jitter is a cause for altering both time and frequency. Time and frequency are not separate entities. They are different points of view of the same thing.

Regards
Dan Lavry
Lavry Engineering

I may be an idiot, or not. Either way I am not insulted, I know which sounds better to me. Salesmen don't disturb me. My motivation was to communicate the reasons for what I hear as I understand them. I don't think I believe you, Dan that no 'jitter' is caused by the delay in the filter, but do as you like. Sadly I have no interest in arguing about it.

Sorry to get your panty bunched.

Curve fitting?

I didn't think so, but it comes down to whether there is delay in the filter, 'homogenization/jittering' between different samplings?

I can say that what the guy is saying matches my experience of NOS, music is much more 'lively', like live music. OS seems more 'Correctly Reproduced'.

Peace.

Aaaah. Thanks for explaining that Dan. My confusion is that I thought jitter only effected time domain in that, for me the easiest to detect examples of jitter are very complex classical pieces where I've heard them in person (pieces from Mahler, or Haydn - with the later things like the harpsichord or harp, violas are instruments I'm most familiar with). Breaking it down like helps because while I'm learning, it's easy to get lost in specific details about the ad / da process, and forget about the bigger picture, forgetting how to "see"/hear everything as a sum, in a 3 dimensional sense. I appreciate you sticking with it as digital audio is by means an easy thing to jump in and understand. In the past when working with recording, cleaning things up for a master it was easy to follow the book of common practices as it were, but understanding the math and theory behind the scenes allows one to make much more informed decisions in the process in place of just doing what appears to sound right. There is a great deal of trial and error in finding the right hardware, none the less making the most transparent recording makes me feel much better about the archival state of the content I work with.

Wouldn't "correctly reproduced" sound like live music? Just to loop back and it's something I talked about in the review of the DA11 I did, I want everything in my system to be as transparent as possible because more often then not, when I find myself listening for pleasure, I enjoy things like the sound of Grado for headphones and the Vienna Acoustics and Sonus Faber sound for speakers. When I have to critique or work on audio I like the HD650 and 600 w/ Cardas or the AKG 701/702. I believe there is a place for adjusting the sound but I want that adjustment made at the very last stage, in the cross over or diagram in the cabinet design, or in the room / acoustics in general.

It's difficult to describe, it's not pace rythym timing, more the sound of breath in a voice whispers more like how you hear it, cohesive on a very fine level. Not just the voices, tho. Attacks and decays are very real sounding.

'Correctly Reproduced'. Sounds good, frequency response, undistorted, etc. but somewhat flat, sterile. Subtleties are not as subtle as they are in life.

I'd recommend having a listen, if you haven't as yet!

Can anybody remember the guys name and website who mounts his dacs bare circuit board on pine boards? He had some scope traces of this but I simply cannot remember! The traces showed 'pre ringing' of the waveforms...

Ah, found it.

Mother of Tone - Time or Band

Then over here you got sigma delta convertors.

Mother of Tone - Conversion Techniques

Altmann. You really trust someone mounting digital chips on wood ?

I'm not against it, lol. The traces were what I was looking for, and thank you for the answer!!!

Then act like one. You don't need to talk down to people to make your points, and telling someone that they posted "garbage" doesn't improve the veracity of your technical arguments.

--Jerome

Honnestly, I think that Mr Lavry is actually a model of restraint by taking the time to explain what is wrong with the paper of Kusunoki. Most professionals would simply shrug it off after calling it a bunch of crap. I mean... just read this: PSW Recording Forums: Dan Lavry => Why do Non Oversampling Filterless DAC sound so good

Dan, maybe you could comment on passive I/V conversion vs opamps as it is thought that no opamp is the best opamp. Also, what are your thoughts on the use of Pulse Transformers at the input of a dac?

You have fairly delicate sensibilities if you think Dan to be unprofessional. I'm not seeing it, again what specifically are you referring to? Remember this is his twenty something go at trying to combat conjecture, hyperbole, and outright opinion in regards to breaking down the actual performance of antiquated dacs (on THESE boards none the less) - given that context, he's a better man than I.

This is the entire reason why trying to keep the record straight is a good idea - Dan has already had to address that wildly inaccurate paper.

I didn't really understand your post regarding headphone preferences, thisbenjamin. I think your sentence may have been missing a few words?

Anyway, I don't want to recommend one headphone versus another or go into specifics. But I own both an HD650 and a K 702. I am planning to recable the K 702. I also have two pairs of iPod earbuds and a Sony MDR-something that is about 10 years old, for whatever that's worth.

(I'm away at the moment, so I may be delayed in replying.)

Wes - I should have been more specific I was referring to Dan in regards to the Grado and AKG's - although it's good to hear someone else enjoys the 702s

Also - thank you Wes for publishing your hardware specs (and usefully ones at that!) as well as standing behind the ICs you chose to use in your product. And what on earth is that... are those measurements from an OEM?! Now i'd like to find out if we have any local head-fi'ers with one of your dacs. is your loaner program still going well, if the que length isn't too crazy, I should jump on that.