John Curl's Blowtorch preamplifier

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The axis are labeled.

I also made CD/SACD tests, and people easily found differences.

Regarding that M-M paper, the only interesting for me is article 4., a note on high-resolution recordings.

The methodology - one of the A-B-X tests, that corrupts signal integrity and stresses listeners making them concentrate to expected change at the moment of switching - no thanks.
 
PMA said:
The axis are labeled.

You must be joking, aren't you?

Originally posted by PMA
I also made CD/SACD tests, and people easily found differences.

I don't believe it. Why should your word here be more credible than a peer reviewed article in a journal?

Originally posted by PMA
The methodology - one of the A-B-X tests, that corrupts signal integrity and stresses listeners making them concentrate to expected change at the moment of switching - no thanks.

The usual GEB :bs:
 
PMA said:
Analog output spectrum of the player in dBVrms vs. frequency, averaged over some period of time. I thought you were smart enough to know.

Admittendly, I'm usually dense at charades. So:

- First graph is a CD player? Model? Analog spectrum while playing what?

- Second graph is a DVD-A player? Model? Analog spectrum while playing what?

- Apparently, the SACD player was playing Ravel? Model? Are you sure you are comparing apples and apples?

Edit: the output can't be noise, so I'm still stumped about what you are comparing here.
 
PMA said:
IMHO in the best way possible. Same player, same D/A converter, no change in cables compared to standard listening conditions, just switch between 16/44.1, 24/96, 24/192 tracks. Same volume level. Same recording equipment. Anything wrong here? (I speak about resolution project disc).

Help! I completely failed in understanding the testing methodology. It would certainly help if you could describe it.

I also fail to understand how http://mixonline.com/mag/audio_resolution_project/ fits in the CD vs. SACD discussion.

But I'm suspecting there's in fact nothing to really understand here, so I am over and out of this topic. This is going nowhere.
 
They used 3 identical Genex units to record the same sessions (at the same time) at different sampling freq and bit depth. There are 2 music samples, jazz and classical, both recorded at 8 different formats and compressions on DVD-A disc. Those of our interest are 16/44.1, 24/96 and 24/192.

I am sorry SY, and appreciate your patience.
 
PMA said:
[snip]I also made CD/SACD tests, and people easily found differences.
[snip


Of course they did. No CD is identical to an SACD, even when having the notionally same piece of music. They are (re)mastered differently, compressed differently, mixed differently.

Moran et all did understand this, and were smart enough to devise a test that circumvented this neatly.

Edit: forget it, just now saw the other posts describinng the special recording.
I'll be back 😉

Jan Didden
 
PMA said:
Jan, do not simplify. You can compare good classical hybrid, like the one I linked.

Or better, make a comment on The Resolution Project Disc (hereabove) methodology.


I will look into the resolution project. But it is my experience that even re-issues of the same CD in a later year can sound quite different that one from an earlier year. So if I would evaluate a change with the CD from 19xx, and you do the same with the *same* CD from 19yy, the results are meaningless. The old adagium to change only one thing at the time always holds.

Jan Didden
 
PMA said:
IMHO in the best way possible. Same player, same D/A converter, no change in cables compared to standard listening conditions, just switch between 16/44.1, 24/96, 24/192 tracks. Same volume level. Same recording equipment. Anything wrong here? (I speak about resolution project disc).

If it were so simple. I have been working on a music server that can switch dynamically between formats. And playing with DAC's in this system have learned that they do not perform identically at different sampling rates. After a few head banging oop's I looked at the data sheets (duh) and the specs are quite different for different sample rates. Even the recovered clock jitter is different (higher) at higher sample rates.

A true comparison is very difficult to arrange. I have heard (along with rooms full of sensitive listeners) clear superiority in hi res recordings but they weren't double blind so they fail the scrutiny of the obsessive. There have been demonstrations where audiences could not hear the difference between live music and an acoustical disk playback, which may illustrate the futility of tests to show the sensitivity of listeners to different sound quality.
 
I have grabbed the Maurice Ravel (spectrum shown hereabove). It says more than any words. Many guys live in pop-rock area, the hirez is of no need there.
 

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