John Curl's Blowtorch preamplifier part II

[elektroj]

Originally Posted by Kindhornman

When we are talking about the difference between 24/96 and 24/196 how much of the difference is because of the differences in clock Jitter and what does it take to actually get the most of the 24/196? I haven't read any technical information on the difference in quite some time and can't remember the actual spectrum changes between the two formats. ........

http://lavryengineering.com/pdfs/lav...ing-theory.pdf

[elektroj]

Originally Posted by chris719

I suppose, I still haven't heard a valid reason why you can't archive with 24-bit 96 or 192KHz PCM.

You can, but what you do if your final release is at different sample rate? Resample? Ouch!

DSD is "universal" 1 Bit stream at 2.82 MHz recorded directly after A to D modulator that allows decimation down to desired sample rate / release format at a later stage - 44.1; 48; 96; 384; whatever ...

http://www.positive-feedback.com/Iss...rinterview.htm

SACDs as such are very precious archives, because they do contain that 1 Bit data. Unfortunate thing is that we (users) do not have direct access to that data and can not choose ourselves the way we'd like to listen to it. Current methods to play back SACDs are somewhat compromised.

P.S. As far as I know, first Sony DSD systems were built around CS5390 ADC where 1 Bit stream could be accessed at one of the test pins.

[abraxalito]

Originally Posted by elektroj

DSD is "universal" 1 Bit stream at 2.82 MHz recorded directly after A to D modulator that allows decimation down to desired sample rate / release format at a later stage - 44.1; 48; 96; 384; whatever ...

And what's one good reason for using a 1-bit modulator in an ADC? Nowadays cheap multibit ADCs with great linearity are available so we can record direct to PCM and bypass the nasty noise modulation issues that come from not being able to control the pdf of the noise in the shaping loop. Or has that problem been solved now?

P.S. Cirrus Logic has gone over to multibit S-D in their later designs - ever wondered why?

[Kindhornman]

elektroj,
Thanks for posting the article. I have to take my time and read the whole article but I get the jist of the concept and sampling accuracy and bit length. No real reason to go over the 96khz number for practical purposes with 20khz wide bandwidth and even going as high as 25khz which should be more than enough it appears that 50khz sampling would still meet the Nyquist ratio. I'll read more when I have time. This article address bandwidth requirements but I will have to look at the jitter situation and clock implementation later. Thanks.

Thanks for your response also Abraxalito. Kind of jumped in here at the end of this thread and I will have to go back and read more of the thread. Don't know where this was fitting into the original thread of preamplifier without going back and reading what happened here.

[elektroj]

Originally Posted by Kindhornman

....
Don't know where this was fitting into the original thread of preamplifier without going back and reading what happened here.

You're right, Kindhornman, this has drifted way off topic. I'll stop now.
Apologies to John for hijacking his thread.

[Johnloudb]

Originally Posted by abraxalito

I speculate that your CD player doesn't have the right kind of DAC chip in it. Stanley Lipshitz says (more to the point, shows) DSD is technically flawed, Lynn Olson says the SACD sounds distinctly different from the mastertape. I can't see any reason to disbelieve either of them. But then maybe you value other aspects in the sound of SACD vs CD to those I do. Or perhaps I have too poor an SACD player.



Now that's beginning to sound more promising... So what does SACD give up to 24/192 to your ears?

You have something against the Benchmark DAC1? In comparisons with CD I can tell very little difference between it and our Oppo BDP83 Nuforce edition.

Good Bluray discs of some live music concerts sound more life like than anything I've heard. It's not just one aspect of the sound, it just sounds more real.

[abraxalito]

Originally Posted by Johnloudb

You have something against the Benchmark DAC1?

Other than the DAC chip used and the layout and grounding, no nothing

Being S-D it won't do justice to 44k1/16 material.

[gpapag]

Originally Posted by fas42

This has been
Frank

I wrote that to say that at least in that case I couldn’t blame the medium or even the playback equipment.
And this original LP/CD release comparison of live opera recording from 1950-60
is not the only one that I have come across.

Originally Posted by hitsware

I.E........... Punch and UnPunch the ' stereo - mono ' button
and hear an obvious differance

Originally Posted by Chris Hornbeck

The diaphragm can only be in one place at any one time, but the motor is different when the coils are driven differently.

All good fortune,
Chris

(Unless the cartridge is of a true “mono” construction), when you play a mono record with a stereo cartridge and watch the signals on a phasescope (or through an oscilloscope in XY mode) you’ll see gross deviations from mono.
All these are due to artefacts atributed to cut/replay process and equipment.
The most upstream (at the cartridge output)one shorts the two channels, the most effective is the accidental stereo to mono conversion.

George

[Groove-T]

Mono records should be tracked with a real Mono Cartridge , including a spherical tip with radius 25 mikrometers.

Stereo should have sherical tips with apx. 16,5 mikrometer radius. Thats also why they have apx. 33% lesser output level with monorecords, but more noise.

[Johnloudb]

Originally Posted by abraxalito

Other than the DAC chip used and the layout and grounding, no nothing

Being S-D it won't do justice to 44k1/16 material.

What do you mean by S-D?

The measurements I've seen look very good. I've read no complaints about how it measures in audio mags.

Anyway I've used a number of very good DACs from PS Audio, MSB and very good CD players. The Benchmark does a very good job.