Jitter -- How low is low?
Aug 5, 2008 at 5:01 PM Post #121 of 151
Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
it would be very wise for you to know when to shut up!


"I give myself such very good advice, but I very rarely follow it." -Alice in Wonderland

See ya
Steve
 
Aug 5, 2008 at 6:02 PM Post #122 of 151
Quote:

Originally Posted by Know Talent /img/forum/go_quote.gif
Yes, I agree and they even mention that in the Audiocom ad (CYA?)...but then they go on to say what an amazing transformation takes place with their Superclock 4 installed... (I had the uber expensive UltraClock installed)

Here's the scoop directly from their website

The CD23 Comes of Age.

The CD23 is essentially made up of two PCB’s, the main power supply & digital PCB, then the audio circuitry PCB is fixed to an aluminium plate and held upside down on top of the main PCB. The Level-1 modification upgrades the main PCB digital & analogue power supplies, employing Black Gate NX for the analogue power supply. Regulator bypass & local digital de-coupling capacitors are also replaced for Rubycon ZA types.

The OEM master clock is a single transistor discrete design, evidently better than the poor quality CMOS inverter based clocks seen in other CD players regardless of price. We were keen to hear how the Superclock 4-S (SC4) would perform in the CD23 and made this upgrade in isolation and listened.

We were keen to hear how the Superclock 4-S (SC4) would perform in the CD23 and made this upgrade in isolation and listened. We can report that this new clock improves significantly upon OEM oscillator. Most notable is the increase in sound-stage depth and projection, a more flowing, organic, relaxing sense of the music. There's more detail, truth of pitch & timbre, bass delineation.

Tonally the CD23 looses that degree of hardness, leanness heard in the OEM player, with SC4-S the tonal balance has a natural warmth and organic flow which makes listening for longer periods fatigue free. Bass is more sure footed, with added energy and power to ensure that the lower registers are more convincing.


.: Audiocom International :. Modifications : Arcam FMJ CD23

Now after reading all that fluffery what would you expect to hear?

I see you also mention analog section mods and I agree they can have a noticeable effect but I am very leary in that area as well because I've had well advertized modders try to sell me on output transformers which up the ouput which to me "muddies the waters" regarding what constitutes "better" performance. Simply jacking up the output does not guarentee better detail, reduced distortion, etc...



Stereophile measured the CD23 at 218 picoseconds. It is doubtful any "mod" to lower that number would help, and possibly might hurt. One of my old UK mags (Hi-Fi choice I think) has a comparison of the trichord mod done to two different players, the article concluded it made the first player sound worse, and the second player different but not clearly better.
 
Aug 5, 2008 at 6:27 PM Post #123 of 151
Quote:

Originally Posted by bigshot /img/forum/go_quote.gif
"I give myself such very good advice, but I very rarely follow it." -Alice in Wonderland

See ya
Steve



I give others advice wich i don't follow myself, bigshot in wonderland.
icon10.gif
 
Aug 5, 2008 at 6:29 PM Post #124 of 151
Quote:

Originally Posted by bigshot /img/forum/go_quote.gif
No they don't. The masters used to cut the records don't have frequencies that high, and neither do the records themselves. The only thing up that high is very low level noise. If there was significant signal at 40kHz, the modulation would be so delicate, one or two playings would turn it into a solid mass of distortion.

I remember back when they had LP test records with test tones on them. Above a certain point, the tones would play fine for a few times, and then start degrading into distortion. You'd have to chuck the record and get a new one after a while.

See ya
Steve



Sorry, why would people report that most 192khz upsamplers sound more analogue? Because they interpolate above 20-22,5khz. Mimiking analogue sound, that has more information above 22,5khz then cd's have.
 
Aug 5, 2008 at 6:29 PM Post #125 of 151
Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
Sorry, why would people report that most 192khz upsamplers sound more analogue? Because they interpolate above 20-22,5khz. Mimiking analogue sound, that has more information above 22,5khz then cd's have.


Frequencies above the range of human hearing have been shown to have no effect on the perceived quality of recorded music. In fact, the frequencies above 10kHz are relatively unimportant compared to those below that range. Get a signal generator and actually listen to what the frequencies you're talking about sound like.

Analogue sound generally has a slight attenuation of high frequencies, not an overabundance of them.

Spelling counts, you know. Keep an eye out for those red underlines.

See ya
Steve
 
Aug 5, 2008 at 6:35 PM Post #126 of 151
Quote:

Originally Posted by bigshot /img/forum/go_quote.gif
Spelling counts, you know.

See ya
Steve



Only if you don't have anything technical to say.

Further more, the second harmonics on records may well beyond 40khz. A 22,5 note has a second harmonics of 45khz, wich a record can deliver, a cdplaer not, since everything above 22,5khz is cut off. because of the higher second harmonics of records, they sound more analogue to people.
 
Aug 5, 2008 at 6:36 PM Post #127 of 151
Quote:

Originally Posted by stereoguy /img/forum/go_quote.gif
Stereophile measured the CD23 at 218 picoseconds. It is doubtful any "mod" to lower that number would help, and possibly might hurt. One of my old UK mags (Hi-Fi choice I think) has a comparison of the trichord mod done to two different players, the article concluded it made the first player sound worse, and the second player different but not clearly better.


The cd23 is a newer player, mine on the other hand might have jitter of 300-500. Now, that you gonna hear. (or not, but i'l let you know once the mod has been done).
 
Aug 5, 2008 at 6:38 PM Post #128 of 151
Quote:

Originally Posted by bigshot /img/forum/go_quote.gif
Frequencies above the range of human hearing have been shown to have no effect on the perceived quality of recorded music. In fact, the frequencies above 10kHz are relatively unimportant compared to those below that range. Get a signal generator and actually listen to what the frequencies you're talking about sound like.

Spelling counts, you know.

See ya
Steve



The best ears in the field can hear up to 25khz, with the second harmonics, that would be 50khz. Hence sacd is using 100khz.

Most records use frequencies between 20hz-16-18khz. meaning the second harmonics are well beyond the 22,5khz limit of cdplayers, hence records sound better!
 
Aug 5, 2008 at 6:51 PM Post #129 of 151
Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
The best ears in the field can hear up to 25khz, with the second harmonics, that would be 50khz.


The highest fundamental frequency in the orchestra and the highest note on a piano is under 5kHz. That allows two octaves of harmonics. I'm not good at the math, but I'm guesstimating that as being almost 10 levels of harmonics. Total overkill.

As for the best ears in the field, are we talking about dogs?

See ya
Steve
 
Aug 5, 2008 at 7:00 PM Post #130 of 151
Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
The cd23 is a newer player, mine on the other hand might have jitter of 300-500. Now, that you gonna hear. (or not, but i'l let you know once the mod has been done).


Given the cost of many of these mods, which seem to start around $450 or so and go up from there- onto several thousand, why not sell your existing player and buy a modern low jitter one? I have 2 stock Denon 2910's for which a "Dexa D clock" mod is offered, but have'nt brought myself to mod one and compare.
 
Aug 5, 2008 at 7:31 PM Post #131 of 151
Quote:

Originally Posted by regal /img/forum/go_quote.gif
Bigshot, I usually always agree with your posts. But I can hear major differences between CDP's and DAC's. If you compare a $300 player that has opamps in the analog stage with a $5000 CDP with opamps inside then yes there is little difference.


The analog output stage of the highly touted several thousand dollar Ayre CDP has Burr brown op amps. The 650 dollar rotel 1072 has burr brown op amps for analog output too. There sure is a difference in the price, eventhough burr brown op amps cost about 5 bucks.
 
Aug 5, 2008 at 7:43 PM Post #132 of 151
Quote:

Originally Posted by stereoguy /img/forum/go_quote.gif
Stereophile measured the CD23 at 218 picoseconds. It is doubtful any "mod" to lower that number would help, and possibly might hurt. One of my old UK mags (Hi-Fi choice I think) has a comparison of the trichord mod done to two different players, the article concluded it made the first player sound worse, and the second player different but not clearly better.


At least I wasn't gullible enough to spend four figures on a powercord!!!

The thing that gets me angry is when people market and sell things based on arguments that "appear" logical...ie reducing jitter for more cohesive sound...

all the bastages selling clocks and powercords should be dipped in elmers, rolled in anchovies and dropped off at the penguin exhibit for the public amusement
 
Aug 5, 2008 at 8:18 PM Post #133 of 151
Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
Sorry, why would people report that most 192khz upsamplers sound more analogue? Because they interpolate above 20-22,5khz. Mimiking analogue sound, that has more information above 22,5khz then cd's have.


I am sorry but that is absolutely incorrect. Upsampling a 44.1khz recording cannot give you any information above 22.05khz that is an absolute impossibility. When a redbook CD is created there is no music content above 22.05 khz, no after the fact processing can ever recover those frequencies they are gone forever. Anything above 22.05 khz that you hear (if you could hear it anyway) with any upsampling scheme will by definition be noise.


Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
Only if you don't have anything technical to say.

Further more, the second harmonics on records may well beyond 40khz. A 22,5 note has a second harmonics of 45khz, wich a record can deliver, a cdplaer not, since everything above 22,5khz is cut off. because of the higher second harmonics of records, they sound more analogue to people.



[/quote]

I am sorry but this is also utterly incorrect. There is no (natural) musical fundamental anywhere near 22.05khz , the highest fundamental on a Piano is about 4.2K to get to even 22.05khz you are several harmonics above the highest fundamentals you will get on anything other than a synth. That it is theoretically possible to have some 40K plus energy on an LP is pretty irrelevant as (1) it will be at a vanishingly low level owing to the physical limits of LP playback and (2) there is no "good" evidence to suggest that it makes any audible difference at all.


Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
The cd23 is a newer player, mine on the other hand might have jitter of 300-500. Now, that you gonna hear. (or not, but i'l let you know once the mod has been done).


There is really no good evidence that jitter at such low levels is at all audible.


Quote:

Originally Posted by tourmaline /img/forum/go_quote.gif
The best ears in the field can hear up to 25khz, with the second harmonics, that would be 50khz. Hence sacd is using 100khz.

Most records use frequencies between 20hz-16-18khz. meaning the second harmonics are well beyond the 22,5khz limit of cdplayers, hence records sound better!



Some folks may be lucky enough to be able to hear to 25K, however if you are talking about anybody over 30 you can forget that immediately. In any case nobody can hear to 50K, thus it is utterly irrelevant. Again , you are talking about second harmonics of 22.05, this is just absurd, there is no non synth fundamental anywhere near that high.
 
Aug 5, 2008 at 9:13 PM Post #134 of 151
Quote:

Originally Posted by nick_charles /img/forum/go_quote.gif
I am sorry but that is absolutely incorrect. Upsampling a 44.1khz recording cannot give you any information above 22.05khz that is an absolute impossibility. When a redbook CD is created there is no music content above 22.05 khz, no after the fact processing can ever recover those frequencies they are gone forever. Anything above 22.05 khz that you hear (if you could hear it anyway) with any upsampling scheme will by definition be noise.


While I agree with your point I would not call it "noise" but instead it is data interpolated from the lower resolution data. Is it physical? no. Can you hear it? I can't (my ears cut out at around 14.5 k) . Even then I still would not call it noise.
 
Aug 5, 2008 at 10:18 PM Post #135 of 151
Nick is using the term noise in its technical meaning, not as a pejorative. If it isn't "signal", it's "noise".

See ya
Steve
 

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