MicroSD Memory Card Transport Project

[jkeny]

Originally Posted by EUVL

I know it is off topic, but the MCLK of the 9022 is only specified at 50MHz max. (20ns). Bearing in mind that mark-space ration of XOs can be 45:55, I think it is better to have so margin, like 40 MHz. Don't you think ?

Patrick

You could well be correct Patrick - have you experienced any issues at 50MHz?

[EUVL]

No, but then I have not built all 20 of them (yet).

Patrick

[Bunpei]

I report my experiences on oscillator replacements on my SDTrans192.

SDTrans192 uses two crystal oscillators, 24.5760 MHz and 22.5792 MHz as master clocks for FPGA to generate I2S signals.
As the asynchronous FIFO buffer circuit for I2S generation designed by Chiaki must be very simple, quality of the master clock seems to be reflected to output sound quality very directly.
(I2S signals are completely synchronizing to one of the master clocks.)

1. Our standard oscillator components are;
Fox Electronics
Xpresso series FXO-HC735 Standard HCMOS Oscillators +-50PPM
FXO-HC735 | Information for FXO-HC735 Series from Fox Electronic
XPRESSO | XPRESSO Crystal Oscillator | Oscillator- Fox Electronics
It's a vanilla. Not so bad, however, we can expect more improvement
by replacing these oscillators.

2. I tried proprietary bipolar output crystal oscillators;
They were designed and produced by
a Japanese audio equipment vendor, FIDELIX
’´’áƒWƒbƒ^�[�…�»”*�UŠí(ƒNƒ�ƒbƒN)‚Ì�»�ì
(This page is only written in Japanese.)
Resulting sounds are less harsh, maintaining a good resolution and musically sounding.

3. The second replacement is;
CMOS output Crystal Clock Oscillator NZ2520SD
manufactured by a Japanese leading crystal maker, Nihon Dempa Kogyo Co., Ltd.
NZ2520SD(OA / AV)/Crystal Clock Oscillators/NDK
http://www.ndk.com/images/products/c...NSA3449E_e.pdf
The model has a remarkable low phase noise profile. According to their measurement result sheet, Phase Noise [dBc/Hz] 26MHz 3.3V for 5 samples
1Hz: max -76,　min -81
10Hz: max -108, min -111
100Hz: max -136, min -138
1kHz: max -151, min -152
10kHz: max -156, min -157

The component is also available for personal users by way of a Japanese online web store, chip1stop. Unfortunately, they have no web page in English. However, you can contact to them through their web page.
chip1stop - One Stop Shopping Procurement Service for Electronic Components -

The price I bought was 1,500 JPY / piece ( 18 USD/ piece ).
My impression for their sounds is "high resolution tones, bass is enhanced accurately." I think this one has very high cost performance and its price
is very reasonable.

4. The last experience is of Mr. Ishida's Rb-based Oscillators;
Frequency Electronics Inc.
Rubidium Frequency Standard FE-5680A

Its technical manual says;
Phase Noise (fo=10 MHz)
@ 10 Hz: -100 dBc
@ 100Hz: -125 dBc
@ 1000 Hz: -145 dBc

I was very impressed by its high resolution tones when I listened to them for the first time. As I have not compared 3. and 4. at the same time,
I can't comment on comparison of 3. and 4.

Bunpei

[jkeny]

Very helpful Bunpei,
Good to see phase noise rather than ppm being shown as a measure of clock quality.
I looked at the NZ2520SD but I don't see 22.5792MHz or 24.5760MHz speeds & I don't see the measurement result sheet you referenced. I presume you ordered these speeds as a special order?

[Bunpei]

Originally Posted by jkeny

I looked at the NZ2520SD but I don't see 22.5792MHz or 24.5760MHz speeds & I don't see the measurement result sheet you referenced. I presume you ordered these speeds as a special order?

They can accept orders for any frequencies in the specified range.
Its price is a standard price. However, their delivery period is three months in the worst case. Minimum quantity for one order is one piece!
As for the phase noise measurement technical data, I got it from a sales person of the company(The document is written in Japanese language).

Bunpei

[90999]

What IO C8051 have? SPI OR SDIO ,I think SPI isn't enough (500KB/S@16MHZ)
Can you get it work in HIGH SPEED and not any error ?

like 24 192 of WAV file, it's 19200 x 6byte /S (1.152MB/S)............

I don't know How do you so fast to play the 24 384 of WAV file.................

[Bunpei]

Originally Posted by 90999

What IO C8051 have? SPI OR SDIO ,I think SPI isn't enough (500KB/S@16MHZ)
Can you get it work in HIGH SPEED and not any error ?
...
I don't know How do you so fast to play the 24 384 of WAV file...

We use C8051F361(Silicon Laboratories). Its clock rate is 24.5 MHz and running at quad speed mode. They say the actual performance is 100 MIPS. Chiaki's firmware is coded in assembly language so as to exploit the maximum performance.

We just use SPI. Chiaki found a "magic" method for reading and transferring data from SDHC memory card to FPGA(I2S signal generator).

Based on the two points explained above, Chiaki obtained enough data transfer rate for 352.8 kHz / 24 bit. However, to our regret, 384 kHz / 24 bit is just beyond the capability of SDTrans192.

Bunpei

[xrcd24bit]

Hi Bunpei,

I am interested in your SDTrans192. Would you please e-mail the price and relevant ordering information to me ?

Thanks in advance

[Bunpei]

Originally Posted by xrcd24bit

Would you please e-mail the price and relevant ordering information to me ?

Dear xrcd24bit,

I tried to send a diyAudio private message to you and failed to do that.
Your user account on the forum seems to reject a private message.
Please send me your ordinary e-mail. My address is
bunpei<at>ta2<dot>so-net<dot>ne<dot>jp

Best regards,
Bunpei

[Bunpei]

As some of you may already know it on Twisted Pear Audio - Buffalo II thread in this forum, playing DXD audio files ( 352.8 kHz / 24 bit PCM WAV files) on "Over sampling Mode" of ES9018 DAC chip by connecting standard Buffalo32s or Buffalo II DAC products to SDTrans192 through I2S interface has some problems, two type of noises and an unstable lock state.
If you replace an original 80 MHz processor clock with 100 MHz one, you can eliminate the problems practically and enjoy a quality of 352.8 kHz / 24 bit sources.
Though Chiaki and Bunpei are making efforts to find a route cause of the problems, we have not identified it and not get effective or possible solutions yet.

The two types of noises are;
A. Continuous white-noise like irregular noise at "STOP" state
(Bit Clock signal is output, but SDATA signal is kept low.)
ES9018 is loosing a lock.
This can be suppressed if you set certain register values for
"AUTOMUTE" setting.
B. A loud "click" noise at the timing of switching from or to 352.8 kHz / 24 bit
file.
You can't remove this noise easily by register setting.

When we get any new findings or corrective measures, we will report them on this thread.

Bunpei