Question about OSS and audiophile 24/96, SPDIF out

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Question about OSS and audiophile 24/96, SPDIF out

Postby Bernard » Sun Jan 08, 2012 1:20 pm

Hi to Everyone,

On my Debian Lenny system, I run OSS with a M-AUDIO audiophile 24/96 soundcard. I have used this for about 2 years, mostly in the purpose of digitalizing vinyl records, using 'ossrecord'. Today, I wish to take advantage of this system to play music. My biggest problem for now, is that my computer is rather far from the place where are my amplifier and speakers ; it is one floor below, and I need about 20 meters of cable to go around walls and stairs. In the other hand, I cannot decide to get everything closer, since I need this desktop PC upstairs, where there is no room for HIFI apparatus, and the 'audiophile 24/96' cannot be installed on a laptop.

Amongst various possibilities, I understand that I could possibly use a digital link between the spdout of my soundcard, and a spdin to my amplifier or other device downstairs. I found very little information about using such kind of a link, the little I read said that such a link was to be shorter than 15 meters if metallic cabling, or 10 meters if optical, except if using a more professional way of transferring digital data, in which case you were allowed longer distances.

If I launch 'ossxmix', I can see that the SPDIF mode can be set to 'CONSUMER' or to 'PRO'... Now, I would need to know more about such possibilities, in order to see if there is a chance that I could link my two systems with such a link. Another question arises too: I am in the understanding that a SPDout can only send 16bit signals... while most of my vinyl records have been digitized to 32 bit float - 96 kHz... Could it be that setting the SPDIF to PRO, allows transferring 32 bits (24) data ?

Thanks in advance for your help

Bernard
Bernard
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Re: Question about OSS and audiophile 24/96, SPDIF out

Postby igorzwx » Sun Jan 08, 2012 1:52 pm

Bernard wrote: I need about 20 meters of cable to go around walls and stairs

The standard (professional) solution is "balanced cables" with XLR or TRS connectors
http://en.wikipedia.org/wiki/Balanced_audio
The good ones are not cheap. You may find them here: http://www.thomann.de/gb/index.html
If you do not know what they are, you may ask Johnny on Audacity mailing list.
Notice that your "professional" devices (souncard, amplifiers, speakers, headphones, microphones, or else) should have balanced inputs and/or outputs. Otherwise, "balanced cables" do no make much sense.

It seems that the ancient LynxTwo souncard (24bit 192kHz record/playback) has XLR connectors http://ixbtlabs.com/articles2/lynxtwo/
There is a "closed source" OSS4 driver for LynxTwo http://manuals.opensound.com/usersguide/lynxtwo.html
You can get it for free here: http://www.opensound.com/download.cgi

Example:
ah Cables KL20FM25 Lautsprecherkabel [Loudspeaker Cable] Neutrik XLR male auf XLR female 20 m grau
http://www.amazon.de/Cables-KL20FM25-La ... 669&sr=1-2
Loudspeakers
http://www.thomann.de/gb/loudspeakers.html
Online Guide PA Speakers
In the digital age, the loudspeaker is the last and unchangeable outpost of analogue technology.
http://www.thomann.de/gb/onlineexpert_151.html

Online Guide Choosing a PA System http://www.thomann.de/gb/onlineexpert_156.html
Whether you’re a fan, a promoter or a performer, the refined craft of live sound is vitally important.
Contents
Sound Sources & Signal Paths
Microphones
Cabling
http://www.thomann.de/gb/onlineexpert_156_3.html
Mixers
Amplifiers
Loudspeakers
Introduction to Acoustics
Putting it all Together
Examples
Glossary
Conclusion

In a word, the git-version of OSS4 plugin for Audacious has "exclusive mode" which allows to "disable redirection to virtual mixer engines and sample rate/format conversions", but it seems to be impossible to disable format conversion in Audacious http://en.wikipedia.org/wiki/Lossy_data_conversion There is also a magic resampler for Audacious. Although the deaf may not hear the difference, it might be interesting to try. If you have questions, you may ask Michal: viewtopic.php?f=3&t=3834
Code: Select all
$ yaourt audacious git
2 aur/audacious-git 20111108-1 (7)
    Lightweight, GTK-based advanced audio player focused on audio quality.
3 aur/audacious-plugins-git 20111112-1 (5)
    Plugins for Audacious
==> Enter n° of packages to be installed (ex: 1 2 3 or 1-3)
==> -------------------------------------------------------
==>

Code: Select all
pkgname=audacious-oss-plugins-git

./configure --prefix=/usr --enable-amidiplug --disable-adplug --disable-pulse --disable-alsa --disable-amidiplug-alsa --disable-resample


The problem is that Audacious is fundamentally wrong by design and, therefore, it does not allow to play an audio file as is, without lossy conversions. It is said to be "GTK-based advanced audio player focused on audio quality". Notice that the word "advanced" means "crap" in the Linux-speak. It seems that the Linux developers are deaf to a certain extent, they are not able to hear the difference. Both Linux developers and Linux users seem to be perfectly happy with PulseAudio, except for a few dissidents who pretend to be able to hear the difference. This does not contradict the fact that the number of Linux users is comparable with the number of the deaf:
http://blogs.adobe.com/open/2011/06/foc ... lient.html
http://research.gallaudet.edu/Demographics/deaf-US.php

Reduced hearing capacity – understanding less and less, almost without noticing it
http://www.sennheiser.com/sennheiser/ho ... ing_living
Symptoms of deafness:
http://www.sennheiser.com/sennheiser/ho ... g_symptoms
Why does our hearing deteriorate?
http://www.sennheiser.com/sennheiser/ho ... ng_reasons
In order to enjoy life to the fullest, you have to hear it
http://www.sennheiser.com/sennheiser/ho ... g_pleasure

The only practical solution seems to be the Russian DeadBeef player with Petrov's plugin for OSS4 (it also has the "exclusive" mode) viewtopic.php?f=3&t=4424 Although that famous Russian "ultimate player" is a buggy crap infected with PulseAudio, it is possible to use it, but you may need to recompile is, of course, to remove PulseAudio and other "very advanced open-source crap":
Code: Select all
# 1. Remove libsamplerate (if you have it installed), before compiling DeadBeef:
# sudo pacman -Rdd libsamplerate
# 2. Remove libpulse, if you have it installed.

  ./configure --prefix=/usr --disable-pulse --disable-alsa --disable-ffmpeg --disable-vfs-curl --disable-lfm --disable-artwork --disable-supereq --disable-converter
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Re: Question about OSS and audiophile 24/96, SPDIF out

Postby cladisch » Mon Jan 09, 2012 12:16 pm

Using balanced cables would probably work, but is not supported by either the AudioPhile nor by any consumer amp.

You could try a coaxial cable, and if this doesn't work, add an SPDIF repeater.

If the pile of additional hardware gets too big, it might be easier to just put a laptop, media player, or media server downstairs.

(SPDIF always transports 24 bits; the Consumer/Professional mode has no effect on this.)
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Location: Earth

Re: Question about OSS and audiophile 24/96, SPDIF out

Postby igorzwx » Mon Jan 09, 2012 1:07 pm

cladisch wrote:You could try a coaxial cable, and if this doesn't work, add an SPDIF repeater.

If the pile of additional hardware gets too big, it might be easier to just put a laptop, media player, or media server downstairs.

(SPDIF always transports 24 bits; the Consumer/Professional mode has no effect on this.)


The problem is that Bernard is not deaf to such an extent. He may notice noise and distortions http://en.wikipedia.org/wiki/S/PDIF#Limitations
Moreover, he is not stupid. If professional audio engineers do not use SPDIF cables for such purposes, there should be a reason for this.

It might be obvious that "balanced cables" are needed for transferring signals for big distances. They should be connected to devices with balanced inputs/outputs. Consumer devices can connected to "professional" ones by very short ordinary cables (e.g. XLR-to-Stereo 3.5mm). This might be a "practical solution" for semi-deaf Linux users.

cladisch wrote:it might be easier to just put a... media server downstairs.

Do you mean a kind of PulseAudio?
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