[DVV]

This is just to let interested parties know that on my site, http://www.zero-distortion.com, in the download section, you can find quite a few schematics of well and little known audio products, several very interesting technical texts, and a number of data sheets for better known transistors and op amps.

Free for all.

Cheers,
DVV

[Hank]

DVV, I clicked on your link and received a "Bad Gateway" error message in return.

[Carlman]

I cut an pasted the address and it worked.  For some reason it doesn't open when you click on it...

[hairofthedawg]

Looks like a comma got included in the link, backspace once after the failure.

cheers,

Dick

[DVV]

DVV, I clicked on your link and received a "Bad Gateway" error message in return.

Beats me why. Anyway, try again by typing in the full address:

http://www.zero-distortion.com

Been working on that address for 15 months now.

Cheers,
DVV

[tmd]

This is a very interesting 'tweak' for better sounding CD's.  I know there has been lots of talk in the past about copies sounding better than originals but the whitepaper here is the most exhaustive and best explained piece I have read.
http://www.genesisloudspeakers.com/newshmfeb03set.html
I am going to start a new thread for this also as it is a big deal all on its own and while it is relevant here, will probably hijack the thread.
Neil.

[DVV]

This is a very interesting 'tweak' for better sounding CD's.  I know there has been lots of talk in the past about copies sounding better than originals but the whitepaper here is the most exhaustive and best explained piece I have read.
http://www.genesisloudspeakers.com/newshmfeb03set.html
I am going to start a new thread for this also as it is a big deal all on its own and while it is relevant here, will probably hijack the thread.
Neil.

After you have made your copy, make sure you put it in deep freeze for 24 hours, than 24 hours in your lowermost fridge shelf, and the last 24 hours at your topmost fridge shelf.

This also works with all existing CDs.

Cheers,
DVV

[DVV]

This is a very interesting 'tweak' for better sounding CD's.  I know there has been lots of talk in the past about copies sounding better than originals but the whitepaper here is the most exhaustive and best explained piece I have read.
http://www.genesisloudspeakers.com/newshmfeb03set.html
I am going to start a new thread for this also as it is a big deal all on its own and while it is relevant here, will probably hijack the thread.
Neil.

Anybody know any big names making black CDs?

Cheers,
DVV

[randytsuch]

Hi DVV,
I have a bunch of black Imation CDR's I bought from compusa awhile back.  Guess I will have to give them a try, and see how they sound.

Randy

[DVV]

Hi DVV,
I have a bunch of black Imation CDR's I bought from compusa awhile back.  Guess I will have to give them a try, and see how they sound.

Randy

When you do, post some feedback, will you Randy? I'm really interested. All in your own good time.

Cheers,
DVV

[CE]

Motown has lotsa black CD's.  some of the best music ever made.  Temps, Isley Bros, Marvin Gaye, Curtis Mayfield, Supremes, etc.

[roopaudio]

Well, looks like I'm late to this digital discussion, but all of my research has led me to divide the CD problem into three stages to conquer - the digital stage, the d->a stage, and the analog stage.

While the above sounds completely obvious, it's important to remember that each stage is completely independant from one another in what's going on and the inherant problems associated with each.

In the digital stage, the main goal is to maintain the quality of the digital signal; i.e. to extract a maximum number of bits, and maintain timing.  Here the principle problems come from jitter and the misreading of bits (sometimes unrelated directly to jitter).  

The D/A stage involves the decision to upsample/oversample, and method of digital to analog conversion.  Be it hold and release, sigma delta, etc... the choice of implementation affects the sonic signature and quality, as well as the number of resolvable bits (assuming a perfect CD).

The analog stage deals with providing gain to the standard 2v output, with a satisfactory low output impedance to be able to properly drive the preamplification stage.  As no D/A chip out there has a native 2v output, some sort of gain is required.  For those of you saying, "wait a minute, the specs of chip XXX state a 3.0v output", you're right and wrong.  Yes, the net output of the chip is 3v, but only due to the use of a built-in opamp.  Is an opamp good to have?  Well, traditionally, they've been frowned upon in hi-end audio, and I think there's good reason.  Opamps require a feedback loop, and we all know how hardcore SET fans are about no negative feedback.  If there's no opamp, some sort of gain stage is required.  This can occur in the form of tubes, transformers if the output is a voltage source.  If the output of the D/A chip is a current source, I/V conversion is required.  I/V conversion has it's own drawbacks, depending on the complexity and implementation.

Well, I'd ramble, but work calls.  The important thing to remember is that any quality implementation will yield good results, but theoretically certain implementations have the possibilities for better quality.  Give me two months, and I'll try to show you exactly how and why

Rup

[Marbles]

But can we afford it

[roopaudio]

Marbles,

I'm sure you could afford it, but honestly I don't know if I can even afford it    .  It's not even a question of a typical audio component markup - silver transformers, a metal CD mechanism, and multiple D/A chips all add up to a tidy sum.  I'm concurrently designing a CD Player with the same technology and implementations but at a much lower price - sort of a "trickle down" philosophy with regards to technology.  On the positive side, both CD players will include well-implemented attenuation, making a preamplifier optional.

Rup

[tmd]

Rup,
Glad to see you dropped by on this one. I still say that unless someone can give me a very good reason why not, a PC (of sorts) as transport with a good PSU and outboard soundcard, perhaps via USB brings more to the game than it takes away. You simply rip all your CD's to the drive and play them into the DAC of your choice, completely separate from the 'transport'.
My very limited understanding of it would suggest that jitter will not be a problem, nor will dirty or imperfect CD's.
Any of M. Barnes dinky little fanless wonders would probably be a good choice for the machine. They can run from 12V, which eliminates mains problems also and they also act as DVD players. In fact, if or when Creative come out with an Extigy 2, you could use it to play DVD-A.
Tell me if I am crazy.
Neil.

[Marbles]

Marbles,

It's not even a question of a typical audio component markup - silver transformers, a metal CD mechanism, and multiple D/A chips all add up to a tidy sum.  I'm concurrently designing a CD Player with the same technology and implementations but at a much lower price - sort of a "trickle down" philosophy with regards to technology.  On the positive side, both CD players will include well-implemented attenuation, making a preamplifier optional.

Rup

Sounds great, keep us informed please.

[roopaudio]

I still say that unless someone can give me a very good reason why not, a PC (of sorts) as transport with a good PSU and outboard soundcard, perhaps via USB brings more to the game than it takes away. You simply rip all your CD's to the drive and play them into the DAC of your choice, completely separate from the 'transport'.
My very limited understanding of it would suggest that jitter will not be a problem, nor will dirty or imperfect CD's.
Any of M. Barnes dinky little fanless wonders would probably be a good choice for the machine. They can run from 12V, which eliminates mains problems also and they also act as DVD players. In fact, if or when Creative come out with an Extigy 2, you could use it to play DVD-A.
Tell me if I am crazy.

Neil,

There are a few problems with the Extigy, and ultimately it does take away from sound quality.  Also, there is a problem in the fact that to minimize timing errors of playback, one has to take the time to copy an entire CD onto the HDD before playback can begin.

Let's assume the USB interface itself is ideal - relatively speaking to the Extigy card the USB interface itself introduces minimal distortion.  We can focus on the problems of the actual Extigy card itself.

While Creative has taken multiple steps in the right direction (as going with the I2S data transfer format over AC97 codecs), their implementation still isn't optimized for 2 channel audio, but more for gaming.

Here's a good place to get started:
http://www.digit-life.com/articles/extigy/

This is an excellent review of the card, as the reviewer takes time to actually print out the performance parameters in a situation where the testing methodology is accurate.  It's rare for audio testing to be done properly at these computer review sites, mostly for the reason that the reviewers are techies and not necessarily aware of audio.  Focus on the 16bit / 44.1kHz analysis section, as that's what is used for CD audio playback.

Creative Labs didn't really focus on optimizing 44.1KHz digital to analog conversion; instead they focused on 48KHz so they could properly market the 24bit/96kHz fad that everyone loves to hype up.  This is representative of an ignorance that higher numbers ensure better audio performance, which couldn't be further from the truth for CD playback.  That, however, is a whole different can of worms.

Getting back to the Extigy, there are serious synchronization problems with the Extigy DSP chip and accepting a 44.1kHz signal - meaning the data has to be sent at 48kHz over the USB cable.  Therefore your 16bit / 44.1KHz signal has already been resampled (meaning, jitter has been added to the waveform) in your PC to a 16bit/48kHz signal before the sound card even sees it.  

Now the Extigy takes the 16bit/48kHz signal, and converts it.  The numbers for noise floor and harmonic distortion in the audible bandwith are very mediocre - 85dB noise floor and 83dB dynamic range within the audible bandwidth isn't particularly impressive when using the volume control (considering similarly implemented players and $300 CD players regulalry have 100dB+ for 24bit, and 96dB is the theoretical performance for CD's).  

Numbers aside, I used the Extigy when operating my HD-600's for a while, and often felt like there was a sense of the timing and pace being slightly off.

I think the Extigy is a wonderful product, especially at the price point.  I applaud Creative for bringing the card to market, and the convenience and features it provides are unmatched.  Also, the use of the internal I2S format is a huge step forward (versus the worthless AC97 codecs).  However, the card just isn't optimized for 16bit / 44.1kHz playback that all audio CD's are encoded in.


Regards,

Rup

[blizzard]

Hi Rup,

Creative Labs didn't really focus on optimizing 44.1KHz digital to analog conversion; instead they focused on 48KHz so they could properly market the 24bit/96kHz fad that everyone loves to hype up. This is representative of an ignorance that higher numbers ensure better audio performance, which couldn't be further from the truth for CD playback. That, however, is a whole different can of worms.

Do you mean that higher bit and sample rates (24/96, etc.) are always inferior to the Redbook 16/44.1.  Or, does it depend?

ie.  There are good 24/96 and bad 24/96 DAC's.  Just as, there are good and bad 16/44.1.

        Thanks,
            Steve[/quote]

[roopaudio]

Do you mean that higher bit and sample rates (24/96, etc.) are always inferior to the Redbook 16/44.1. Or, does it depend?

ie. There are good 24/96 and bad 24/96 DAC's. Just as, there are good and bad 16/44.1.

Steve,

I agree with you completely.  In fact, just a few replies previously, I wrote the following:

The important thing to remember is that any quality implementation will yield good results, but theoretically certain implementations have the possibilities for better quality

Scroll up, and you'll see those exact words towards the end of one of my posts.  That being said, I've spent the past year writing a design thesis explaining exactly why an optimally implemented 16bit D/A is more accurate to human ears versus and optimally implemented 24bit D/A when decoding Red Book CD format.  It will be published at the end of next month.

Regards,

Rup

[Marbles]

I've spent the past year writing a design thesis explaining exactly why an optimally implemented 16bit D/A is more accurate to human ears versus and optimally implemented 24bit D/A when decoding Red Book CD format.  It will be published at the end of next month.

Regards,

Rup

Um yea, but when will the DAC be built