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Old 18th December 2009, 05:59 PM   #91
jgazal is offline jgazal  Brazil
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Join Date: Dec 2008
Question Questions

I was wondering how to mount the PCB inside a diy case.

This layout seems very well thought and the opening for SD card slot could be placed in the front panel.

LCD panel is already removable so it can also be placed at the front panel.

Although it would be possible to extend lead wires in parallel from the board to new buttons attached to a custom panel, it would be preferable to have a removable panel with all the control buttons (similar to the LCD panel) in order to make things easier for diy'ers.

Alternatively, there would be no problem mounting the pcb on a wood base. A dust cover could be used to let things clean.

However, this raw alternative let me a bit concerned about RFI/EMI.

Does the PCB have 4 layers with ground plane for shielding?

Does someone have any idea as to shield I2S signal from transport to DAC?

I see that spdif is transmitted with coaxial cable, which can be shield. But which shielded cable could be used for I2S?

Which word depth and sampling frequency the spdif interface accepts? 24bits / 192khz?

Congratulations for achieving 24bits / 352.8khz. This feature makes this transport very unique.

Best regards,

Jose Luis
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Old 19th December 2009, 10:31 AM   #92
Bunpei is offline Bunpei  Japan
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We appreciate your interest and consideration very much.
Our answers are inserted between your questions.

> Does the PCB have 4 layers with ground plane for shielding?
Yes, exactly.

> Does someone have any idea as to shield I2S signal from transport to DAC?
A cabling method from the transport to a DAC may depend on its length and frequency. In our case, a flat cable, less than 15 cm is used.
Of course, you can use such a co-axial cable as 1.5C2V. We recommend that you check waveforms with an oscilloscope. In some cases, you may need to add or insert termination registers.

> I see that spdif is transmitted with coaxial cable, which can be shield. But which shielded cable could be used for I2S?
As described above, you do not need to use co-axial cables necessarily. There is no cabling standard on I2S.

> Which word depth and sampling frequency the spdif interface accepts? 24bits / 192khz?
On our SDTrans192, CS8406 is used for S/PDIF transmission. The maximum resolution the chip can transmit is 192 kHz / 24 bit. The chip seems to accept 32 bit I2S signals actually.
As you may know, the maximum bit length in S/PDIF standard is 24 bits.

Bunpei
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Old 20th December 2009, 12:21 AM   #93
Bunpei is offline Bunpei  Japan
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Quote:
Originally Posted by Bunpei View Post
Chiaki succeeded in playing a 352.8 kHz /24 bit DXD audio file with a combination of his SDTrans192, specially tuned version, and ESS Technology's ES9018 2CH evaluation kit. However, due to a clock crystal frequency limitation of the DAC board, he has just confirmed the play on "NOS" (No over sampling, skipping a built-in FIR filter) mode setting of the DAC chip. He will replace the crystal with one with an adequate frequency and try on 8 x over sampling mode soon.
Ultimately Chiaki has achieved a play of 352.8 kHz /24 bit DXD audio files on 8 x over sampling mode of ES 9018 DAC chip! A high-frequency processor clock for the DAC chip is generated by a 4 x frequency multifier implemented in FPGA from 22.5792 MHz TCXO source in SDTrans192.

We believe that this is the first device capable of playing 352.8 kHz /24 bit DXD audio files among a SD memory player or PC-based audio device in the world. The only device I have known in the market is AX24 of Digital Audio Denmark targetting a full professional use.
Chiaki has developed this device by himself. Only manufacturing PCB was outsourced. He designed the circuit & artwork, programed firmware & FPGA and handsoldered SMD parts without any help of others.

Bunpei
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Old 26th December 2009, 07:34 PM   #94
macrog is offline macrog  New Zealand
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Smile Wow congratulations on a truly impressive achievement

Well done that is amazing. Have you considered selling the finished product in a case. I for one would jump at the chance.
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Old 27th December 2009, 03:13 PM   #95
Bunpei is offline Bunpei  Japan
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Quote:
Originally Posted by Bunpei View Post
A high-frequency processor clock for the DAC chip is generated by a 4 x frequency multifier implemented in FPGA from 22.5792 MHz TCXO source in SDTrans192.
Yesterday, I could listened to the sound of some 2L DXD files ( 352.8 kHz / 24 bit PCM Integer WAV format ) using Chiaki's SDTrans192 and ESS Technology ES9018 2 CH Evaluation Board with 100 MHz oscillator for processor clock.
(Chiaki replaced an original 40 MHz crystal with a 100 MHz oscillator module.)
Not a S/PDIF but an I2S interface was employed.

I think I could well detect a fine structure even among faint string vibrations in contrast to its 96 kHz version when we replayed 352.8 kHz version of Hydn String Quartet. It's truely an amazing experience for me.
In the case of comparison of Britten Simple Symphony of 192 kHz version with 352.8 kHz one I could recognize a certain improvement in the 352.8 kHz file.

Bunpei
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Old 27th December 2009, 03:24 PM   #96
Bunpei is offline Bunpei  Japan
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Quote:
Originally Posted by macrog View Post
Have you considered selling the finished product in a case. I for one would jump at the chance.
Thank you very much for your proposal.
To our regret, we have no idea of selling a finished product in a case.

Instead, Chiaki is planning to release 10 kits at the next timing
(hopefully within one or two months) and we have four tentative reservations for the kits as of now.

Bunpei
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Old 7th January 2010, 09:14 AM   #97
Bunpei is offline Bunpei  Japan
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Default T.H.E. Show Las Vegas Exhibit

Quote:
Originally Posted by Bunpei View Post
Instead, Chiaki is planning to release 10 kits at the next timing (hopefully within one or two months)...
You may find a pilot sample of the new revision kit at an exhibition space of Japanese Kiso Acoustic Co., Ltd. on T.H.E. Show 2010.
They may use SDTrans192 with a CHORD DAC for a demonstration of their speaker products.(Therefore, No 352.8 kHz/24 bit nor 192 kHz/32 bit are available).

Bunpei
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Old 26th January 2010, 01:16 PM   #98
Bunpei is offline Bunpei  Japan
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Quote:
Originally Posted by Bunpei View Post
Instead, Chiaki is planning to release 10 kits at the next timing (hopefully within one or two months) and we have four tentative reservations for the kits as of now.Bunpei
We have delivered 4 kits of Rev.2.1 PCB with a new price of 450 USD. We'd like to express our gratitude to those who accepted the new price and purchased the kits. We have no reservations now.

Mr. Ishida, a very active Japanese audiophile and one of the four new users, reported on his blog in Japanese language
SDTrans192外部クロック入力化 ケンのオーディオメモ/ウェブリブログ
that;
A. He put the board into a plastic case.
B. He connected SDTrans192 to gigaworks DAC using I2S.
C. He injected external master clock signals (22.5792 MHz & 24.576 MHz ) generated by Rubidium-controlled Oscillators ( FE-5680A ). (Each frequency of raw oscillator output is doubled by a PLL device.)
As a result he said he obtained a highly-focused sound with superior SNR.

Bunpei
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Old 31st January 2010, 02:00 AM   #99
Bunpei is offline Bunpei  Japan
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Quote:
Originally Posted by Bunpei View Post
C. He injected external master clock signals (22.5792 MHz & 24.576 MHz ) generated by Rubidium-controlled Oscillators ( FE-5680A ). Bunpei
Yesterday, at elecon's site at Tokyo, I listened Mr. Ishida's SDTrans192 with Rubidium-based external clocking units.
The effect was especially and easily detectable on 352.8 kHz / 24 bit 2L DXD sources. I think its sound is the most perfect and accurate among digital sounds that I ever listened though my experiences are limited.
I felt every single tone was maintained as non-degradated. I was astonished that even a faint diminishing sound of strings and piano held its fine structures.

Mr. Ishida prepared his clocking systems after his vigorous efforts.
However, costs for materials are not so expensive at all.

He selected Rubidium Oscillator FE-5680A that was easily available at eBay.
1 Hz to 20 MHz|Programable Rubidium Frequency standard - eBay (item 290301888238 end time Feb-03-10 05:56:05 PST)
As SDTrans192 requires two master clocks, 22.5792 MHz & 24.576 MHz, he prepared two units.
Click the image to open in full size.
(If you send appropriate commands to the unit by way of a serial control line, you can change its output frequency easily. This time, he prepares two units of pre-set.)
FE-5680A's frequency limit is 20 MHz and its output wave shape is sine-only. Mr. Ishida made a multiplier with sine->square shaping using Phase Link PLL502-02 and a comparator.
http://www.phaselink.com/pdffiles/PLL502-02.PDF
Therefore, two FE-5680A were set for 11.2896 MHz and 12.288 MHz, respectively.
The multiplier & comparator unit is shown on a sub-board appearing to the right side of SDTrans192. He also tweaked SDTrans192 clocking circuits in order to accept external clocks.
Click the image to open in full size.

I'd like to express my gratitude to Mr. Ishida and "elecon" who offered his excellent audio room and equipment for listening tests.
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Old 6th February 2010, 05:28 PM   #100
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Would be nice to have detail for the external clock multiplier and comparator circuit and which are the modification at the transport in order to accept the external clock?
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