- Storage: Solid State Storage (SD etc.) connected to FPGA based dev. board.
- Control: Simple controls (play/pause, stop, next, prev) with on board switches.
- Display: No display, maybe a 7-segment.
- Output: Direct SPDIF generation -I should check if it is possible with readily available gpio voltage/current options- or on-chip sigma delta dac with external output filters.
- Clock: Master or slave.
Limited storage
User unfriendly
Absolutely silent ! Bit-perfect ! Jitter ?! Synchronization ?!
What do you think ?
Anyone have attempted to do such thing before ? Anyone wanna try ?
MB
- Control: Simple controls (play/pause, stop, next, prev) with on board switches.
- Display: No display, maybe a 7-segment.
- Output: Direct SPDIF generation -I should check if it is possible with readily available gpio voltage/current options- or on-chip sigma delta dac with external output filters.
- Clock: Master or slave.
Limited storage
User unfriendly Absolutely silent ! Bit-perfect ! Jitter ?! Synchronization ?!
What do you think ?
Anyone have attempted to do such thing before ? Anyone wanna try ?
MB
http://www.ghielectronics.com/details.php?id=5&sid=7&PHPSESSID=29a5e2672bb397f97de75b5a3d565943
How about GHI Electronics?
They already have USBThumb MP3 Player. Some Mod (maybe tiny CPLD) will generate I2S signal from WAV file.
How about GHI Electronics?
They already have USBThumb MP3 Player. Some Mod (maybe tiny CPLD) will generate I2S signal from WAV file.
http://www.mikrocontroller.net/articles/ARM_MP3/AAC_Player
http://www.k9spud.com/traxmod/
http://www.robotparts.com.au/ump3.htm
I found them.
First guy does not use VS100x (stream processor), generic DAC.
So it means he can generate I2S signal (can be easily converted to SPDIF) from WAV file on SD Card.
http://www.k9spud.com/traxmod/
http://www.robotparts.com.au/ump3.htm
I found them.
First guy does not use VS100x (stream processor), generic DAC.
So it means he can generate I2S signal (can be easily converted to SPDIF) from WAV file on SD Card.
I found VS1033,
This is new version of MP3 decoding chips, and it has I2S output.
So If you get one of MP3 DIY players using VS1001 etc then replace to VS1033, you can get WAV(44.1/16) to I2S portable.
VS1033 normally uses 12.88MHz clock (for 48kHz) so it have to be changed.
http://www.vlsi.fi/vs1033/vs1033.shtml
This is new version of MP3 decoding chips, and it has I2S output.
So If you get one of MP3 DIY players using VS1001 etc then replace to VS1033, you can get WAV(44.1/16) to I2S portable.
VS1033 normally uses 12.88MHz clock (for 48kHz) so it have to be changed.
http://www.vlsi.fi/vs1033/vs1033.shtml
I was reading the CD player transport thread today and it got me thinking. Then I looked down and saw the thumbdrive and said viola! The things are ubiquitous, very inexpensive, and could hold most of a CD or two of compressed lossless audio. First you rip the CD with CD Paranoia to get the best copy. Then copy to a thumbdrive. This way you have a backup on the hard drive "just in case" as well as the original. Thumbdrives don't care about scratches and fit in pockets easier than CDs, plus you can put whatever mix of music on each one you want. Just USB -> Decoder -> DAC.
This "ultimate source" is an interesting idea. I was thinking in the car for these holidays.
There are some issue.
(1) Read SD card by MCU
Some DIY MP3 player already does it.
I think Daisy MP3 is good base for modify.
(2) make I2S signal
Almost Electrical DIYers does not care it. they are using VS1011 or something (MP3 stream decoder). by using VS1033, it can be done. but...
(3) make I2S signal 44.1kHz/16bit faithful to sourse, high acculate clock
VS1033 contains SRC and output is 48kHz. It can not be acceptable for audio maniacs.
So we need some hardware to make this conversion.
(a) PIC RAM buffer to FIFO
2 x 74HC164 and some glue logic, PIC firmware can do it.
(b) FIFO
SN74V245 is 4K x 18 fifo, $9 at digikey.
(c) FIFO to I2S
11.289MHz(256fs) as master clock, /4(64fs) as bit and counter clock, then 64 state and LRCLK / SDOUT generator (2 x 74HC165+glue logic) will make I2S signal.
Will Anyone try? If I do, it will be from some month later.
There are some issue.
(1) Read SD card by MCU
Some DIY MP3 player already does it.
I think Daisy MP3 is good base for modify.
(2) make I2S signal
Almost Electrical DIYers does not care it. they are using VS1011 or something (MP3 stream decoder). by using VS1033, it can be done. but...
(3) make I2S signal 44.1kHz/16bit faithful to sourse, high acculate clock
VS1033 contains SRC and output is 48kHz. It can not be acceptable for audio maniacs.
So we need some hardware to make this conversion.
(a) PIC RAM buffer to FIFO
2 x 74HC164 and some glue logic, PIC firmware can do it.
(b) FIFO
SN74V245 is 4K x 18 fifo, $9 at digikey.
(c) FIFO to I2S
11.289MHz(256fs) as master clock, /4(64fs) as bit and counter clock, then 64 state and LRCLK / SDOUT generator (2 x 74HC165+glue logic) will make I2S signal.
Will Anyone try? If I do, it will be from some month later.
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.
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.
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?
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?
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
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
tinears02 said:
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
alvaius said:
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...
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.
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.
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
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
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/product_info.php?products_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.
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/product_info.php?products_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.
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