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Up to the Minute: Streaming Bits to Audiophile DAC

I have some unanswered questions from another thread, and also some new ones despite searching the archives. So I hope this thread might be a good place for all of us who are interested in state of the art audio quality from hard disk drive based files.

Kublakhan in another thread suggested using the Sweetwater Creation Stations as hardware for a PC based audio solution and so far this gear looks pretty good to me.

My questions, however, arise from the fact that there may be some disconnect between the conventions for "pro audio" and "audiophile" audio.

So as of this writing, can anyone please explain:

Why does every pro audio person seem confused when I tell them I want to use an external DAC?

What is the BEST way to extract bit for bit data from a hard drive, to export to an audiophile DAC?

Why oh why do expensive $$$ music or media servers, which are supposedly configured to optimize audio use, nonetheless require some sort of cheapo "interface" to stream the data into an audiophile DAC?

Why on earth would I want to buy an audiophile "sound card", which I presume (in addition to an "interface") also has its own DAC?

Given the options which are available for "sound card" and/or "interface" type devices, what is the BEST way to tap the bitstream and/or maximize performance of the audiophile DAC? Optical? TOSLINK? Spdif?

Given the choices I might have for the "interface" between the computer and the DAC, what is the BEST way to minimized "jitter" or other audiophile nasties? Or is that phenomenon more of a downstream issue AFTER the bitstream hits the DAC?

There is a lot of great information in the other threads about ripping, tagging, Foobar vs Itunes and a million other complications of hard drive based audio.

But for now, I would really appreciate just some basic, conclusive opinions on the best way to get bits off the hard drive and safely on their way to my speakers from an audiophile DAC.

Please advise.

THANK YOU.
cwlondon
kpavey
1 posts
 
Have you considered an evaluation board DAC? Crystal Semi and Analog Devices (among others) offer them at reasonable prices - add a low noise PSU (batteries or soft recovery diodes etc) and you're away. Most have a digital direct input for I2S. You can mod the output stage for transformers (eg Lundahl microphone type) or tubes as you see fit if you don't like transistors...

Then build up a USB to I2S convertor - such as one at www.dddac.de and you're away.

I've done the above on an AD1896 eval board and it works just great.

Cheers, Kendrick
audioengr
3,282 posts
 
Kpavey wrote:
"Then build up a USB to I2S convertor - such as one at www.dddac.de and you're away."

I looked at this design. I uses the PCM2707 TI chip. This means that it can only use the Windows drivers and will not pass 24/96. IMO, this chip is only useful for Wi-Fi, which is already limited to 16/44.1 and does not require any driver because it is networked. For USB, you need a non-windows driver to get good sound quality.

Steve N.
racerxnet
49 posts
 
Jitter is dependant on the last out device to the DAC. How the DAC handles the jitter depends on the build quality. Bits are bits, period. Whether SPDIF or Toslink does not matter to the DAC. If there is electrical interference, that is a different ball game. If you are concerned about noise from the PC, you can put a ferrite core on the cable to the sound card. Use a Toslink or SPDIF cable to the DAC. That should eliminate the interference problem for the majority of users. The Red Book standard is 44.1 and the upsampling can be done with the external DAC. My Tri Vista 21 samples 96/192. Bit perfect output via my Chaintec 710 card has been verified by me. Foobar kernel streaming bypasses Windows Kmixer, as well as ASIO drivers. No need to get expensive sound cards, unless you are using the onboard DAC's from the card itself. Otherwise the external DAC is useless when using analog output from the sound card. Foobar is free and quite easy to set up. It is convienient when playing music, as it is all in front of you with just a click away.

PC built by me.
Tri Vista 21 DAC
Toslink connection
Levinson Pre
Levinson 33H Mono Blocks
Genesis 201 4 column speakers w/ 1000 watt Amp
SDI modded Apex DVD player and Sampo firmware
2 Ehome 8500 CRT's blended

One hell of a setup that sounds and looks fantastic.

MAK
cwlondon OP
1,198 posts
 
MAK

Finally, someone is making a lot of sense - thank you.

Could you give more detail, please on how we get the bits from the PC to the DAC without using a soundcard.

An "interface"(?) What connections, cables etc could I order when building my own PC?

What is the cost no object, best audiophile solution to then use the external DAC of your choice?
audioengr
3,282 posts
 
racerxnet wrote:
"If you are concerned about noise from the PC, you can put a ferrite core on the cable to the sound card. Use a Toslink or SPDIF cable to the DAC. That should eliminate the interference problem for the majority of users."

This technique will certainly attenuate HF noise from the computer, however it will actually make the jitter worse. It will slow the risetimes of the S/PDIF or AES signal edges and cause the receiver to switch at less accurate/predictable times as a result.

The best solution is to isolate the digital conversion and final clocking from the computer completely. This way, the jitter can be made extremely low. Either USB or Wi-Fi accomplishes this.

Steve N.
Empirical Audio
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