Lossless SD-card player - Page 3

-ecdesigns- · 27th March 2009, 12:22 PM

SD-card player prototype is working, there are some minor problems with SD-card latency, this will be solved by doubling RAM buffer size.

SD-card access is software-driven, I2S signals are generated by the on-chip DCI module and through DMA.

The player already supports multiple directories (99) and multiple tracks within each directory (99 track / directory). Long file names can be used as well.

Shuffle play (CD / tracks) also works.

Bit clock jitter can be kept very low as expected. First impressions of sound quality are very good.

The SD-card latency limits max. sample rate and bit depth. The latency is basically caused by the on-card controller, and may vary with SD-card brand.

glt · 27th March 2009, 02:50 PM

Very nice. Any photos?

Onnosr · 27th March 2009, 03:15 PM

Quote:

Originally posted by glt
Very nice. Any photos?

John

Congrats to you (and brothrer!)

Onno

EUVL · 27th March 2009, 06:46 PM

How about user interface (display, remote, ....) ?
And when would you be offering to us ?

I have a serious interest in the frontend part, up to I2S output.
There are just too many limitations in the Koonlab version.

Pls keep us posted.

Patrick

spzzzzkt · 27th March 2009, 11:33 PM

Just came across this...

http://www.compactstick.com/

it seems the only stuff being released in this format at the moment is psychedelic trance, however it will be interesting to see if this becomes more widely adopted.

There is specification for the filesystem layout here:

http://www.compactstick.com/cs_contents_v10.pdf

UV101 · 28th March 2009, 12:40 AM

Could a Squeexebox be used to output I2S?

If so, it will handle FLAC no problem?

Whilst the media os not solid state, has no mechanical and servo parts which I think is the point of this thread??

Ian

jackpipe · 28th March 2009, 01:22 AM

ecdesigns, are you planning an electronic control (user) interface of some kind? This would make it a very useful module for other projects.

There are a ton of cheap transflash and sd players (also mp4 video) from china around for between $20 - $35. Do you think any of these would be hackable for i2s or some kind of digital output?

tinears02 · 28th March 2009, 04:01 AM

ecdesigns,
It would be very useful to buffer both the clock signals
going to the dac and dsp, as changes in the impedances
or pll pulling (if that happens in the internal circuitry)
will cause some jitter. It will be a pity to loose the
clean clock to this.
Also, make sure all impedances are matched as far as
you can from chip pin to external circuitry.

Looking forward to the final thing!

-ecdesigns- · 28th March 2009, 10:09 AM

Hi git,

The prototype is built around a Microchip DV164027 MPLAB debugger module:

http://nl.farnell.com/microchip/dv16...questid=734245

We added a SD-card holder, an external 2.8224 MHz low jitter clock, and a stereo DAC for testing.

The microcontroller is a DSPIC33FJ128GP802.

I try to make and post some photographs of the test set-up soon.

EUVL · 28th March 2009, 10:17 AM

John,

I hope you would offer a dedicated board before long.

I like your designs, not only this one but also your TDA154x DACs, especially the linear interpolation. Innovative stuff, as one often finds in designs coming from the Netherlands.

Patrick

28th March 2009, 12:40 AM	#26
UV101 diyAudio Member Join Date: Dec 2008 Location: Oxford	Could a Squeexebox be used to output I2S? If so, it will handle FLAC no problem? Whilst the media os not solid state, has no mechanical and servo parts which I think is the point of this thread?? Ian __________________ When Bitstream came out, I thought, “my God, what are we going to do...?” Ken Ishiwata http://www.hifisounds.co.uk Restek Fantasy, Audio Aero Capitole MKII, Focal and Kimber "Leave Nothing as Standard"

28th March 2009, 04:01 AM	#28
tinears02 diyAudio Member Join Date: Sep 2003 Location: earth	regarding hardware design ecdesigns, It would be very useful to buffer both the clock signals going to the dac and dsp, as changes in the impedances or pll pulling (if that happens in the internal circuitry) will cause some jitter. It will be a pity to loose the clean clock to this. Also, make sure all impedances are matched as far as you can from chip pin to external circuitry. Looking forward to the final thing!

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27th March 2009, 12:22 PM	#21
-ecdesigns- diyAudio Member Join Date: May 2006	SD-card player prototype is working, there are some minor problems with SD-card latency, this will be solved by doubling RAM buffer size. SD-card access is software-driven, I2S signals are generated by the on-chip DCI module and through DMA. The player already supports multiple directories (99) and multiple tracks within each directory (99 track / directory). Long file names can be used as well. Shuffle play (CD / tracks) also works. Bit clock jitter can be kept very low as expected. First impressions of sound quality are very good. The SD-card latency limits max. sample rate and bit depth. The latency is basically caused by the on-card controller, and may vary with SD-card brand.

27th March 2009, 02:50 PM	#22
glt diyAudio Member Join Date: Oct 2004	Very nice. Any photos?

27th March 2009, 06:46 PM	#24
EUVL diyAudio Member Join Date: Oct 2003	How about user interface (display, remote, ....) ? And when would you be offering to us ? I have a serious interest in the frontend part, up to I2S output. There are just too many limitations in the Koonlab version. Pls keep us posted. Patrick

27th March 2009, 11:33 PM	#25
spzzzzkt diyAudio Member Join Date: May 2005 Location: Melbourne	Just came across this... http://www.compactstick.com/ it seems the only stuff being released in this format at the moment is psychedelic trance, however it will be interesting to see if this becomes more widely adopted. There is specification for the filesystem layout here: http://www.compactstick.com/cs_contents_v10.pdf

28th March 2009, 01:22 AM	#27
jackpipe diyAudio Member Join Date: Mar 2007	ecdesigns, are you planning an electronic control (user) interface of some kind? This would make it a very useful module for other projects. There are a ton of cheap transflash and sd players (also mp4 video) from china around for between $20 - $35. Do you think any of these would be hackable for i2s or some kind of digital output?

28th March 2009, 10:09 AM	#29
-ecdesigns- diyAudio Member Join Date: May 2006	Hi git, The prototype is built around a Microchip DV164027 MPLAB debugger module: http://nl.farnell.com/microchip/dv16...questid=734245 We added a SD-card holder, an external 2.8224 MHz low jitter clock, and a stereo DAC for testing. The microcontroller is a DSPIC33FJ128GP802. I try to make and post some photographs of the test set-up soon.

28th March 2009, 10:17 AM	#30
EUVL diyAudio Member Join Date: Oct 2003	John, I hope you would offer a dedicated board before long. I like your designs, not only this one but also your TDA154x DACs, especially the linear interpolation. Innovative stuff, as one often finds in designs coming from the Netherlands. Patrick

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