alexd wrote:

by the way we are using Analog Devices dac IC in 16 bits version (DAC18), we will be using<br>Texas Instruments in our 24 bits version (coming soon). The DAC18 got its name, because it took 18 month to create this product. It is not intended for music server application,<br>but for highest quality Red Book&nbsp; CD reproduction.

jessie.dazzle wrote:

In my case, the CD transport (which is no slouch) is soundly beaten. Apart from using it to make the occasional comparison, I have not touched the CD transport since unpacking the DAC.

Jessie, I see an inconsistency in what you say. You are pleased with your USB DAC driver from you DAW but you still load files to you music server from CDs, that mean that you still read then via some kind of transport, would it be DAW transport of external dedicated audio transport. Where I see the contradiction is in my view is that what we look at the performance of the transports we need to abstract ourselves from our takes on DACs. Feed the DAW’s transport and dedicated audio transport into the same DAC. Do you still feel that it is “soundly beaten”? 

Let me give you a test to discover for yours where the sound is been lost. Find a raw stream from any good A/D converter. You must not use DVD-A, SACD of any other souses – they are already ruined by media. You need a raw 16/44stream from A/D. Save it in 16/44 format and listen it from you music server. Then use any available fore you mean to put this file to CD and read it from any transport you have. No matter what you do you will have severely worsened sound, make a conclusion.

The point is that CD format itself, not even the 16/44 is a bitch. The same is with any other format. You might have a good 24/96 file but as soon you load it to DVD-A it turns to shit. A raw 1-bit at 2.8224 MHz DSD is very fine but ported to SACD disks is it loses a lot, not to mention that the whole DSD conversion saga is a fraudulent in a way. The transports of DAC is not a problem the media is the problem. So, the fact that you do not touch the CD transport since you did whatever says very little as you still are touching a CD transport each time you are uploading you CD to you DAW.

scooter,

I think you are not clearly understand at what kind “forum” you are participating. There is no “board awareness” and there are no needs for any “board demo trail”. One of the accomplishments of this site that people do not give a damn about other and everyone on their own. I insist that it is the way how it shell be and if you propose other alternatives the you are in a wrong place. There are absolutely no needs for “group consciousness”. If you like Alex’s DAC then contact him directly and do not convert this site inot AA of DIYAudo type of crap. There is no need for you to discuss or to argue the subject of the “horde evaluations” any further in this thread.

alexd wrote:

The issue of properly handling FM signal is related to the capabilities of your A/D converters. Your A/D converters have analog and digital anti-aliasing filters and delta-sigma modulated A/D chips.

Actually if I am not mistaken my A/D do not use any delta-sigma modulated A/D chips as it is a pure multibit A/D. It is not important however. What is important is that for sake of A/D conversion the FM recording is surprisingly nasty thing. FM cares its stereo information in subcarrier up to 53kHz and if the subcarrier and the 19kHz pilot are not properly killed then they interferes with A/D inputs. Anyhow, this is not the subject of FM and it’s recording so I would call myself for a discipline. However, the message I would like to send that there is no need to demean FM as some kind of inferior sources. In my home FM beats hands down any other source and if you have a good local station then it would do in your home as well. Saying it, I do aknowledge and understand all limitation of FM.

alexd wrote:

Even then, every recording is highly depended on recording engineer's taste and skills. In your home set-up, you have very limited control, almost everything,  except gain is preset.

And here is where the live FM broadcast acting as a liberation force, taking the “taste and skills recording engineers” (which are mostly insultingly-barbaric) out of the consideration. It is my favorite subject but it s not the subject of this thread, I have a separate forum dedicated to off-air audio.

I still feel that computer CD readers are not good but I do it might not be ONLY their fault. Most of the today machines have CD-Rom that juts spin too fast and it is imposable to make a CD-Rom to read at 1x speed. There is many custom softwares that restrict CD-Rom speed. Jessie, if you read your CD with computer then can you try something like this?

http://discrotate.sourceforge.net/index.html

It shell be quite a help. I do not use MAC but the similar tools on PS I remember helped a lot.

Romy wrote :

"...Jessie, if you read your CD with computer then can you try something like this?

http://discrotate.sourceforge.net/index.html..."


Yes I can try it, but I don't know if it will work on the drives where I store music files, as it is an external RAID arrangement, connected via Fire Wire 800.

In theory, apart from reduced wear and noise, I'm not sure that slowing the HDD would have any beneficial effect (in my case, the HDDs are all but noiseless).

My understanding is that chunks of data are collected from the spinning HDD, and then go into a buffer (temporary storage) until called upon. High access speeds and a large buffer will allow the process of data collection "to get further ahead". Data is then called out of the buffer as needed, and is eventually fed to the DAC. Slowing the HDD would logically result in less use of the buffer.

I see the handling of buffered data as similar to that which might occur in devices not having a spinning HDD. I have never experimented with devices that use only flash memory in place of a mechanical HDD (the new Mac AirBooks for example).

Btw, my RAID arrangement is configured such that it allows the computer to distribute data over all drives, which results in high access speeds. No, I don't know if this is necessarily desirable. Furthermore, should one of the drives take a dump, it will effectively wipe out the entire library (meaning that backing it up somewhere else is a must).

On another note : I realize that it is not the same thing as slowing the HDD, but the iTunes interface does allow the user to specify the speed at which data is imported/encoded... I have tried importing CDs at various speeds, right down to 1 X ; I notice no difference in quality. I have not however tried this with "Error Correction" option defeated (to access this option : iTunes > Preferences > Advanced > Importing > Check the "Use error correction" box... Default is un-checked).

For info : "According to a quick bit of research", 1 X speed for CDs = 500 rpm at center and 200 rpm on the outside.

jd*

Here is an excellent article in Positive Feedback by Dave Clark about the current options in the fields of Computer Audio

http://www.positive-feedback.com/Issue41/ca_intro.htm

Dave interviewed 13 designers with surprisingly reasonable questions. I would like also to see among the interviewees Dan Lavry,  Ed Meitner, Michael Ritter and Pflash Pflaumer. Also, I would like those big shots of digital industry to use their pull to make more Hi-Res raw files available as today audio people foolishly copy 16-bit CDs to this music severer and consider that it is how it shall be…

Anyhow, the Positive Feedback’s article is very good.

jessie.dazzle wrote:

Depending on the systems capacity to multitask, EAC may not slow gathering all the way down to 4X. jd*

Romy the Cat wrote:

Also, I would like those big shots of digital industry to use their pull to make more Hi-Res raw files available as today audio people foolishly copy 16-bit CDs to this music severer and consider that it is how it shall be… The caT