Traxmod Open Source SD player

[jean-paul]

When searching for the SD card player on the picture above I found this lossless sd card player that might be interesting as well:

http://www.k9spud.com/traxmod/

 

[Hisatugo]

The SD-card player is not a simple building block that solves all problems associated with digital audio sources. Everything must still be maticulously tuned ...

Oh, I do realized that on second reading of this thread... You´re right - will follow your advice.

I think even to get two players, as if I decide to modify one, still have the other intact..



Thanks... I´m still in line for the player.

Regards everyone.

Hisatugo

 

[jkeny]

Good find Jean-Paul - I wonder has anybody here heard this player?

 

[EUVL]

I knew about this for quite a while (2-3 months).

In the previous versions, the player was meant to play MOD files in the first place. It seems that since he changed over to dsPIC3x family, the emphasis has been placed on WAV files at 44.1kHz.

http://www.k9spud.com/wiki/TRAXMOD:FAQ#Will_TRAXMOD_have_an_LCD.3F

Still, not sure by incorporating too many functions like FLAC and later MOD decoding, performance is not compromised. Also seems only to support 2GB SDs.

http://www.k9spud.com/forum/read.php?3,2497,2498#msg-2498

(Different emphasis...?)

I think Koon's solution is still the simplest, but stagnant. But Traxmod may have much better support and constant update, and is very much alive.

Should keep an eye.


Patrick

 

[scott wurcer]

Looks like a nice open source project. They seem to be optimizing for low power at the expense of other things.

 

[EUVL]

Yes, but I think if the code can be adapted for best performance (rather than versatility), the rest (hardware, layout, whatever audiophile stuff, etc.) we can do ourselves.

I hope the moderators can splitt the last4-5 posts off to a separate Traxmod thread, so that we don't hijack John's.

I'll write to him (k9spud) and see whether he'll help us.


Patrick

 

[EUVL]

> I'll write to him (k9spud) and see whether he'll help us.

Done.

 

[jean-paul]

Looks like a nice open source project. They seem to be optimizing for low power at the expense of other things.

After reading the information I can not conclude that they optimize for low power at the expense of other things or it should be the missing backlight LEDs for the LCD. What I do see is that ( besides FLAC compatibility ) low power consumption is one of the primary design goals which by now should be standard design practice Energy is a valuable thing in 2009.

I guess the author got fed up with portable gear not working ( and also not being portable as it has to be connected to a charger ) at the time you want to use it. For some reason I can fully understand that frustration.

Just look at, for example, mobile phones. They can do all kind of tricks but the modern ones have a depleted battery in less than 1 day.... My old one with black and white screen and no camera has a battery that lasts for over a week. What is the use of color screens and cameras when your battery is empty

 

[jkeny]

Yes this would be a good project to take in the direction of an audiophile version of this player.
So what would we need to do
- take out all code dealing with playback of MOD audio files
- add in code for WAV playback
- look at the hardware for inclusion of low jitter clock & clean power supplies
- maybe modularise it so as to be able to use a selection of DACs
- I would be interested in future ethernet support as it could allow for a useful interface

 

[scott wurcer]

Energy is a valuable thing in 2009.

Tell that to Nelson Pass . I guess I meant that some playback quality issues were not as important as portability and battery life.

BTW PIC has free TCP/IP stack so Ethernet is a real possibility.

 

[EUVL]

If you want ethernet, buy a TEAC WAP4500 for 400 Euros. Everything included ;

WAV, FLAC, MP3, ..... (God knows what else)
USB storage (people are using TB hard disks)
Remote with fully colour matrix display (shows front cover in FLAC)
Ethernet
Built-in DAC (so you can probably tap I2S)
SPDIF optical output
...
etc.

See

http://dspd.teac.de/index.php?id=3821
http://dspd.teac.de/index.php?id=3814

http://www.hifi-forum.de/viewthread-181-2427.html
http://www.hifi-forum.de/viewthread-181-1746.html
(German only)

http://s3b.directupload.net/file/d/1814/5m6jake4_jpg.htm
http://s1b.directupload.net/file/d/1814/cfis6np2_jpg.htm

http://s10b.directupload.net/file/d/1815/r2fsvvf6_jpg.htm
http://s2b.directupload.net/file/d/1815/x5aq8fpg_jpg.htm


Patrick


PS the Teacs are competitors to Logitech Squeezebox & SB Duet, except that it has 2 key features which I like -- USB storage device (so you can just use a stick, e.g.) and play WAV (SB doesn't, only compressed).

The product is new (Dec 2008). For the first 6 months or so, there were still software bugs and required patches update. But I think the buyers are now mostly satisfied, and found the USB and WAV features good. The only complaint is the remote (with complex graphics) which loses connection and needs resetting from time to time (like my USB wireless mouse!!), and some complaint that you cannot locate your files in a 1TB harddisk quick enough !!!!

What people expect these days for 400 Euro !!

The DAC is a Wolfson 24 bit 192kHZ, if I am not wrong.

 

[EUVL]

The reply from Traxmod :

http://www.k9spud.com/forum/read.php?3,2497,2519#msg-2519

I guess he wants FLAC and MOD decoding, and is not too interested in WAV only.

We can copy as is, seems to be the message.


Patrick

 

[jkeny]

Cheaper solution than the Teac would be one of the Network Media Tank (NMT) boxes at about half this price. Based on a chip from Sigma Designs, it will process any video or audio format that you throw at it. No WiFi but can operate from an internal disk or a server via LAN (gigabyte ethernet). Will do multichannel 24/192 & can be operated with RC via TV display or without TV via MPD.

BUT, like all these systems, they are not manufactured with DIY audio members concerns addressed - low jitter clock & minimal interference from extra functionality i.e excessive gates firing in chips while audio playback is in operation. I like the way both ec-designs & K9spud try to minimise processing during audio playback.

Personally, I would settle for 16/44 playback (optimised for best sound) but I do think a useful interface is needed to browse library, set-up playlists, etc. Like the NMTs it's preferable that it's not a screen attached to the player so as to avoid the extra chips, complexity & processing needed but just a way of using the player as a soundcard or ethernet DAC with control over the network. So while playback is being performed on the player, the files on the media server can be browsed (using any device), playlists created, cover art viewed, etc, all without any sonic impact (extra processing) for the player.

 

[EUVL]

> I like the way both ec-designs & K9spud try to minimise processing during audio playback.

Traxmod has FLAC / MOD decoding running in the uP, so not minimal processing.

Koon's is.

> but I do think a useful interface is needed to browse library, set-up playlists, etc. Like the NMTs it's preferable that it's not a screen attached to the player so as to avoid the extra chips, complexity & processing needed but just a way of using the player as a soundcard or ethernet DAC with control over the network.

What frequency is Ethernet running at ?

All these extra things like display, file management, remote, .... is best done in a separate uP which has a simple interface (e.g. RS232) with the dsPIC, which only plays music, like in ECDesign. But I don't think Traxmod wants that because he has a different focus -- size and consumption.

So I don't think you'll get your ideal solution from any of the three options.

I myself can live with Koon's. ECDesign would be nice but I don't like TDA1543. And then it is probably very expensive, judging from his other prices.


Patrick

 

[awpagan]

What frequency is Ethernet running at ?

Bus info
http://www.interfacebus.com/Interface_IC_Buses.html


"I myself can live with Koon's. ECDesign would be nice but I don't like TDA1543"

But the 1543 uses I2S input.

As long as were using I2S data, use a dac with I2S input.

allan

 

[jkeny]

Patrick,
Have you found the id of SD player posted by Redhorseaudio or even deciphered the chip ids?

I guess Ethernet communication could be added to Koon's design - TCP/IP stack support is supported in the dsPIC uCs. Freq of 10, 12.5 or 31.25 MHz but I'm not sure what your objection to this is as long as it's kept electrically & environmentally isolated from the DAC.

So what's missing from Koon's design?

 

[EUVL]

> But the 1543 uses I2S input.
> As long as were using I2S data, use a dac with I2S input.

As long is he is using standard logic level I2S, yes. But he's not.

> So what's missing from Koon's design?

SD > 2GB, fragmented files, interface for remote (RS232 or whatever), otherwise not much actually. I will do one in any case to try out, in a couple of month's time.


Patrick

 

[jkeny]

> So what's missing from Koon's design?

SD > 2GB, fragmented files, interface for remote (RS232 or whatever), otherwise not much actually. I will do one in any case to try out, in a couple of month's time.

OK, so:
- SD > 2Gb - is this hardware or s/w restriction?
- Fragmented files - if SD is cleared & all files copied in one procedure then fragmented files only occur because of bad sectors? - minor problem? - I think Koon says that it can handle some but not a lot
- IR interface is probably not too big an issue to implement in hardware but s/w?