Computer CDROM as Transport??
Jul 12, 2005 at 6:21 PM Post #16 of 28

machead

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Quote:

Originally Posted by Scrith
I think with a program like EAC (or its equivalent on the Mac, whatever that is), the actual device probably doesn't matter (that is, assuming any CD-ROM can actually read a regular CD error free...I would think they all can do this!).


Unfortunately, that's not necessarily the case...

CD playback includes many mechanisms to compensate for media errors that are present on almost all CDs. Some of the correction is implemented in the CD drive firmware, some in the audio ripping software, and some just falls through the cracks. For a useful introduction to the topic, you may find this link helpful. Dedicated CD players generally do the best job, because they only have to work at 1X speed!

There is no direct Mac equivalent of EAC, unfortunately. On all but the worst discs, however, you can get equivalent results by using iTunes to rip to Apple Lossless format, with error correction turned on. The files stored on your hard disk are about half the size of the "raw" AIFF files. When played back through iTunes, your USB audio out (or optical out, if you're lucky enough to own a G5) will contain a bit-perfect copy of the audio stream on the original disc, to feed to your favorite external DAC.
 
Jul 12, 2005 at 7:09 PM Post #17 of 28

philodox

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I'm not familiar with the AQVOX, but it looks like they are following good design methodologies... similar to the Eastsound in fact. What does one of these cost? It sounds like you have taken some good steps to removing dirty power from your computer... although I'm not sure about the power supply. I'm not saying it is bad, but it is a far cry from what is found in high end stand alone components. The 'through the wall' idea is good, but makes accessing the PC a bit of a pain.
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Jul 12, 2005 at 7:49 PM Post #18 of 28

sgrossklass

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Quote:

Originally Posted by machead
Dedicated CD players generally do the best job, because they only have to work at 1X speed!


By the lines of this argument, a computer should be able to do a yet better job, since it can take as long as it wants and read again and again and again and (...) if errors appear. Naturally the law of diminishing returns applies, but a CD player only has one try to begin with. Of course the reading quality of computer drives does vary a fair bit, depending on the mechanics, pickup etc., but there are quite a number of drives that'll do DAE well.
 
Jul 12, 2005 at 8:19 PM Post #19 of 28

Jon L

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Quote:

Originally Posted by philodox
I'm not familiar with the AQVOX, but it looks like they are following good design methodologies... similar to the Eastsound in fact. What does one of these cost?


I'm not so sure about that. USB input is limited to 44.1kHz, which is a bumber. It also doesn't seem to have user-selectable upsampling frequency; it's either 192kHz or none (44.1). I don't like how 192kHz upsampling sounds much and much rather would have choice of 88.2 or 176.4kHz.

But it does look to be well-executed, and I wonder what the price is.
 
Jul 12, 2005 at 8:29 PM Post #21 of 28

sgrossklass

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Quote:

Originally Posted by cosmopragma
No need for power conditioning as far as the PC is concerned, jitter spec of the RME is 3 ns peak to peak inside a noisy PC IIRC, and my DACs ignore reasonable amounts of jitter anyway.


3 ns isn't particularly low, though I don't know how p-p would translate to average. IIRC <300 ps could be considered pretty good, with something down to 100 ps being excellent.
http://www.tnt-audio.com/clinica/jitter2_e.html
About DACs ignoring jitter, well, I've come to have my doubts there. These guys make some good points:
http://www.lessloss.com/types.html
The question of minimizing jitter introduced by the cabling involved remains, but provided you've got that under control, the solution with the slaved source seems like the best bet. It's not the most flexible, of course. (Whether I'd agree with their multi-bit vs. sigma-delta DAC assessment is another matter entirely; IMHO all the top-class DACs are good enough to make the analog chain and the "rest" the bottleneck anyway.)
 
Jul 12, 2005 at 9:56 PM Post #22 of 28

cosmopragma

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Quote:

Originally Posted by philodox
What does one of these cost?


650 Euros, about $776 at the current exchange rate.I call it a bargain.Over all I like it far better than the Benchmark.More musical, better soundstage/headstage, less "digital" sounding, but slightly less detailed and a bit "slower".German engineering, assembled in China under german supervision, therefor quality- and pricewise not easy to compete with.
The implemented LEF- and CI-techniques (whatever that exactly is
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) seem to provide an unique sound.This is not just another good DAC.I'd go so far to say that there is SS-, tube-, digital switching and LEF-sound nowadays.I feel the uncontrollable urge to listen through a pure LEF rig.There are LEF power amps, and some german audiophiles have already reported that an easily affordable LEF amp and a K1000 are a dream team.Could improve my speaker audio, too.We will see.
Quote:

The 'through the wall' idea is good, but makes accessing the PC a bit of a pain.


Admittedly the K1000 makes me look like a dork, but I'm no complete idiot.Keyboard, mouse, LCD and remote control are on my side of the wall, naturally.
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Jul 12, 2005 at 10:16 PM Post #23 of 28

cosmopragma

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Quote:

Originally Posted by sgrossklass
3 ns isn't particularly low, though I don't know how p-p would translate to average.


Following a rule of thumb you can divide the number by eight to get an idea what measuring the average would look like.
This isn't stellar, but the point is that modern resampling DACs like the AQVOX, Benchmark, Apogee or RME Adi are not influenced by such low jitter.You don't need better specs, would be wasted.
I have a 10 m (~ 33 ft.) crappy plastic fibre Toslink cable for listening on the balcony which I got for less than $10 at my local electronics store.Relative to the soundcard jitter this cable surely induces jitter like hell, but doesn't make an audible difference.A semidecent 6 m XLR extension cable for my K1000 in contrast does make an easily discernable difference.
 
Jul 12, 2005 at 10:27 PM Post #24 of 28

cosmopragma

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Quote:

Originally Posted by Jon L
I'm not so sure about that. USB input is limited to 44.1kHz, which is a bumber.


The USB connectivity is a marketing gimmick, I don't use it.Going the ASIO output --> Asio4all --> USB Audiocodec --> DAC - way in order to bypass Kmixer isn't working reliably, you get "beyond logic" messages too often.I have a girlfriend, and the last thing I want in my life is more "beyond logic" trouble.
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Jul 12, 2005 at 10:33 PM Post #25 of 28

Glassman

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Quote:

Originally Posted by Jon L
I'm not so sure about that. USB input is limited to 44.1kHz, which is a bumber. It also doesn't seem to have user-selectable upsampling frequency; it's either 192kHz or none (44.1). I don't like how 192kHz upsampling sounds much and much rather would have choice of 88.2 or 176.4kHz.

But it does look to be well-executed, and I wonder what the price is.



nothing's easier than putting the SRC into bypass mode and leaving just the inherent 8x oversampling if you like integer ratios.. you can even select between slow or sharp filter characteristics and also select sigma-delta oversampling rate.. that box looks like a demonstration unit for an ASRC and DAC chip
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everything you can set using DAC's registers is accessible to user on front panel, cost nothin' and looks cool
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Jul 12, 2005 at 10:34 PM Post #26 of 28

philodox

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Quote:

Originally Posted by Jon L
I'm not so sure about that.


I just meant as far as no opamps, class a, etc.
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Jul 13, 2005 at 1:29 AM Post #27 of 28

Jon L

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Quote:

Originally Posted by cosmopragma
The USB connectivity is a marketing gimmick, I don't use it.Going the ASIO output --> Asio4all --> USB Audiocodec --> DAC - way in order to bypass Kmixer isn't working reliably, you get "beyond logic" messages too often.I have a girlfriend, and the last thing I want in my life is more "beyond logic" trouble.
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Why on earth are you using ASIO out into ASIO4All? I just use ASIO output in Foobar for my Lynx card, which works beautifully. ASIO4All has been disappointing sound-quality-wise compared to ASIO output, especially when doing upsampling. I know, I know, it's supposed to sound the same..
 
Jul 13, 2005 at 9:34 AM Post #28 of 28

cosmopragma

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Quote:

Originally Posted by Jon L
Why on earth are you using ASIO out into ASIO4All?


I tried to utilize ASIO4all because the USB Audio Codec is no ASIO device.( BTW foobar's kernel streaming doesn't collaborate with the USB Audio Codec either).
In my main rig I'm using digital out of a RME soundcard.Originally I purchased a used card from a fellow head-fier about 16 months ago when it was FOTM here.I was looking for a decent SQ for my second rig, but I found the analog section of this card, well, hmmm, forget it.
Disappointed at first this card grew on me.
Lately I had to rebuild my second PC from scratch.I had to work through a 2 page check list in order to get a simple uncorrupted data stream.
I don't need that.
I don't need updating, bugfixing, setting up and whatnot too many stuff.
I don't need maintaining unnecessary checklists and special backups to begin with.
In contrast the RME is totally boring.Throw the card into the computer, install the drivers, done.Bitperfect low jitter ( low enough for my purpose)digital audio.Not a single flaw or failure during the last 16 months.Three different digital outputs, and they can be used parallely.

I really should get rid of this madness and simply purchase a second used RME.
 

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