ultimate source

[tinears02]

Thanks for the ideas.
Would it be difficult to add/change to usb thumbdrive instead?
These are cheaper round here, and their
memory capacity seems to go up just as fast.

tinears02

[KOON3876]

http://www.alfat.co.uk/ualfat-dev.html

uALFAT will be good for ThumbDrive.
They also has MP3 breakout board and sample source, so you can try step by step

(1) ThumbDrive MP3 Player
(2) ThumbDrive WAV Player
(3) using VS1033, ThumbDrive WAV Player with I2S output (but SRCed)
(4) using custom hardware + FIFO + good clock, ThumbDrive WAV Player with Perfect I2S output.

WAV I2S source without Motor, or AC noize, very low power usage = very low effect to clock! What a Cool one!

It will sounds like heaven.

[tinears02]

Interesting!

It occured to me that there are MP3 FM modulators
out in the market for ridiculously cheap prices.
These take a usb thumbdrive and modulates
an internal FM transmitter.
Do these output an analog audio signal
somewhere in the signal path that one
can tap out and use?
In such cases, only a 12V supply is required.

A much cheaper route, no?

[alvaius]

Interfacing to IDE/ATAPI is not that hard and some microcontroller development boards support a hard drive.

I see where you are coming from this, but some comments:

- As soon as you go SPDIF you introduce jitter throwing out the benefits of what you are trying to achieve. Directly into a DAC will be best. You could always use a good ADI or TI DAC eval board and modify the components for better sound.

- If you get ambitious, why not interface a large SD card to a microcontroller so that you can get several CDs?

- One of the things I have been playing around with is a microcontroller eval with wireless 802.11. I am interfacing to a networked harddrive that I have about 500CDs of uncompressed audio on. It is going slowly but I am getting files and audio out. I am going to interface that optically to an external DAC board. The DAC board will have a 64K fifo on it. When it is half empty, it tells the micro board to go get some more data. That way there is 0 jitter other than the clock with no contribution from the optica I/F. The optical I/F will keep all the noisy and asynchronous clocks of the micro board away from the critical DAC section.

- I may even get ambitious and build the DAC board right into my AV processor .. we will see

[KOON3876]

Originally posted by tinears02
Interesting!

It occured to me that there are MP3 FM modulators
out in the market for ridiculously cheap prices.

Hi, like these?
http://www.vr-3.com/fmmod_vr3.php
they looks like using VLSI Solutions VSxx and USB Host device.
(new version supports WMA / like VLSI supports WMA in new version)
If I find one at Walmart tomorrow, I will purchase one and look inside

Originally posted by alvaius
Interfacing to IDE/ATAPI is not that hard and some microcontroller development boards support a hard drive.

I see where you are coming from this, but some comments:

Hi, I think metebalci want to make perfect source for DIY DACs.
Now we know "jitter" caused by motor rotation, optical laser and position control, etc. Battery + SD Card(or USB Thumb) + MCU + I2S output will be most desirable solution for DAC DIYers. 802.11 and low power dev board , maybe can work same.
No motor, no high power device, no AC transformer, no SPDIF, Direct no modification I2S output will be ultimate source for DIYers includes me. I want to connect IT to my TAS5518 directly...

[tinears02]

Hi

Yes, I2S output is what I would like. SPDIF or audio is
not desirable, sorry for not myself clearer. My point is that
this is already done - how does one do it for
high quality audio ?

The VS1033 is a slave device according to the
VLSI Solutions website:

http://www.vlsi.fi/vs1033/vs1033.shtml

It says
"VS1033 receives its input bitstream through a serial input bus, which it listens to as a system slave."

I think the VS1033 is a bit overkill, I would like to
use an external dac and possibly, even my own
stable clock. I am not much of a digital/comms
person, but I think from a quick perusal of the
datasheet, that this is possible.

[KOON3876]

I think the perfect device for "Ultimate Sourse" is dsPIC33.

http://www.microchip.com/

it has DCI module, "Data Converter Interface", supports I2S output. and DMA controller + Buffer RAM supports seamless data supply to DCI module.

There are many samples to read SD/MMC/CF or ThumnDrive by PIC. Only one missing is controlling DCI/DMA to make I2S signal from WAV file.

I want to go this way but my PIC C compiler(CCS PCW) does not supports dsPIC

[KOON3876]

Originally posted by KOON3876
I think the perfect device for "Ultimate Sourse" is dsPIC33.

Just a quick schematic of "Ultimate Source", KOON version.

It only targets to create I2S signal from 44.1/16 wav file.

dsPIC33 will use 30mA or so, it will eat < 50mA total.
what a power eater.

[KOON3876]

I got e-mail from VLSI they says VS1033 is not production now, and samples are only for company request with project description.

So we need some months to get it in market.

I should go to dsPIC33

[KOON3876]

Request for comment
attached is a quick designed board for prototyping.

Dimension: 2.5 x 3.8
U1: dsPIC33
U2: 11.2896MHz master clock
U3: 5V for LCD
U4: 3.3V
J1: 8x2 Character LCD
J2: I2S output
J3: SPI connector, adjusted for http://www.sparkfun.com/commerce/pro...roducts_id=204
but you can connect any SPI device.
J4: PIC ICSP
J5: Power In (I assume 9V battery cell)
SW1-5: Play, pause, stop, FF, Prev
Some surplus holes (right side of U1)

I will order parts / place on paper, then board, so I'm not sure I can get board before holidays.