MicroSD Memory Card Transport Project

A bit expensive @ 350USD...
Have you considered making a conventional through hole board for this project that the average DIY'er could easily assemble? Obviously some of he parts need to be SMT so you could provide a part assembled board for a much reduced price ;)

At first we had imagined just the style you proposed here.
However, this circuit is very complicated and requires two type of loading operations for CPU firmware and FPGA program. These necessarily require a finished product.
We decided to provide this kit with fully-assembled, firmware & FPGA program -loaded and initially tested manner.

(By the way, Chiaki is doing all the assembly processes by himself excluding manufacturing a 4 layered PCB. He is soldering every SMT parts by his own hands. It's incredible! )

Bunpei
 
Isn't I2C connection already planned to add a volume microcontroller? Is it the firmware ready to this function?

Soundcheck, some DAC's have this option already (i.e. TPA Buffalo 32 bits, via I2C plus “volumite” microcontroller). You could use all them together. :spin:

Bunpei, have you considered designing a SDHC transport that streams back DSD (from DFF/ DSDIFF/DSF files)? It would be terrific! :D

As for I2C command output or register setting of DAC chip via I2C, Chiaki has at least embedded an initial "Over-sampling mode setting" that enables 192 kHz play for WM8741 chip. However, no volume setting is built-in currently. I really miss this.

As for DSD handling, we have no plan on it because we are just a packaged media/Internet distributed audio file playing people. Very few DSD file sources are available now. Moreover, such commercial products as Korg MR-1, MR-1000 are already in a market. They have well established a very high performance with reasonable prices for recording and playing with DSD formats.

Bunpei
 
When we think of "a digital volume control", two approaches are possible.
1. This player outputs volume cntrolled PCM data.
On this point, we can't do this because our CPU 8051 has no enough power to achieve this.
2. This player outputs I2C commands for controling an external DAC device.
It might be possible if we could target such a specific DAC chip as WM8741.

I hope "soundcheck" will understand these difficulties well.

Bunpei

Yep. I do understand the challenge.
I do see the same challenge with the ec-designs SD-card player.

However more and more people run direct DAC-Amp connections and do the DSP part on the PC. IMO an SD-card player with whatever DAC attached to it should come with some kind of volume control "option" to make it a complete solution.


Anyhow - the point is - I am running currently all DSP work on the PC side. Any filtering/VC can be done in 64bit. One workaround could be to manipulate all files prior to transferring them to the SD-card. This way one can get rid of an control further downstream. Of course you'll lack any control during playback.

Cheers
 
However more and more people run direct DAC-Amp connections and do the DSP part on the PC. IMO an SD-card player with whatever DAC attached to it should come with some kind of volume control "option" to make it a complete solution.
I usually monitor DAC output using earphones. I agree with you.

Anyhow - the point is - I am running currently all DSP work on the PC side. Any filtering/VC can be done in 64bit. One workaround could be to manipulate all files prior to transferring them to the SD-card. This way one can get rid of an control further downstream. Of course you'll lack any control during playback.
As I am compuer-minded, I prefer the approach also.
 
Bunpei, I have seen you are searching for 32bit files (floating point).
Which 32bits sampling (or maximum data rate) this newer transport support?
Have you already tried DXD 24bits/352.8khz?
1 Gb files at High Resolution Music DOWNLOAD services!
I know DXD 11.2896 Mbit/s data rate is too high, but I would like to know if it is feasible.
Oh, you have read my post on Twisted Pears Sabre32s DAC thread.
We are seeking "true" 192 kHz 32 bit PCM(Integer or floating point) format audio files. I know that the 2L site releases "Hires" audio files. It's really precious. As you may know, however, they distribute no 32 bit format files there. DXD 24 bit/352.8 kHz is just of 24 bit.

By the way, our SDTrans192 kit includes 4 GB SDHC memory card that initially stores those 2L hires files. They generously gave us a permission to do that. I'd like to express our gratitude for their courtesy.

Bunpei
 
I am now playing with the SDTrans 192 via I2S to a ES9018 powered DAC/preamp with remote control (Volume, mute, input selection).
A LU1014D JFET poweamp drives my AMT fullrange horn speakers:D

My other sources - Denon DVD-A1XV and Mac Mini / iMac / MacBook Air (SSD) with iTunes / Songbird / Foobar2000 - are far behind in performance.

A ES9022 DAC are also playing, but as I am waiting for some parts the ES9022 plays a couple of days only single end and the JFET amp needs a balanced input to play good and have only 1/4 power (1 watt) in single end..

But the ES9022 outperforms my DAC with dual mono Wolfson DAC chips even if the ES9022 plays only in single ended modus yet..
 
As you see on the attached photo the SDTrans 192 plays 32bit.
I converted a 192kHz/24bit file without dittering.
And the same file plays much better - more depth in soundstage and more body in the instruments.
And I had to listen several times because I also heard something that sounded like noise..
The "noise" was from the recording studio - breathing, artists moving etc..

I expect the ES9018 plays better due to volume was not changed, but with data on the last 8bits the level will be higher when playing 32bit...

I converted the 01-Britten-Simple_Symphony_Op4-192_24.wav file from 2L recording.
 

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Chiaki and Bunpei were much pleased with your remarkable report! Wonderful!
Thank you very much for your challenge. It's really a great honor to Chiaki.

Bunpei

I have made a 8GB SD card with 21 recordings at 192kHz/32bit...
I am just now playing the SD card for the first time and have come to #16 without any problems, and I really enjoy the audio quality.

With the JFET poweramp and the fullrange AMT speakers and the ES9018 based DAC I believe I have the best sounding setup ever made.
 
Whoops; forgot to say that vinyl playback also will continue heading high-end audio into the future, and that it probably will survive most current (and already short-lived past) digital formats. While concentrating on analog; I do not see a conflict with the leading edge digital development (like SDTrans & ESS Sabre32 playback of true 32 bit files).

The better one know excellent analog playback, the more one will appreciate the best of digital playback.

I am also happy & proud of my Norwegian heritage when new entries like 2L - the Nordic Sound arrives in the market. Some of the best sound recordings in classical and jazz are from Norway. Jan Erik Kongshaug (jazz) and Arne Akselberg (ex-Simax) come to mind in addition to the "newer entries".....

Audio would be nowhere without the performing & recording artists!
 
I have made a 8GB SD card with 21 recordings at 192kHz/32bit...
I am just now playing the SD card for the first time and have come to #16 without any problems, and I really enjoy the audio quality.

With the JFET poweramp and the fullrange AMT speakers and the ES9018 based DAC I believe I have the best sounding setup ever made.

Ray,
I meant to ask you about your LU1014D JFET poweramp - is this a Susan Parker "Zeus"?
Your system sounds wonderfully minimalist - just the right amount of needed components & no more! What are you using for volume control - a lightspeed?
 
Ray,
I meant to ask you about your LU1014D JFET poweramp - is this a Susan Parker "Zeus"?
Your system sounds wonderfully minimalist - just the right amount of needed components & no more! What are you using for volume control - a lightspeed?

The LU1014D JFET poweramp are my own design and uses a JFET as regulator / virtual capacitor, and uses silicium carbide rectifiers etc..
Volume are digitally controlled ES9018 and / or my own optocoupler variant that are mostly / basic like the lightspeed..
You will find pictures and info if you search for my previous posts..

Bunpei & Chiaki I am sorry for OT in your thread..
 
... I would certainly be very interested in purchasing the finished product.

Our kit is a kind of "finished product" already because it runs by connecting power and a S/PDIF cable to the board. However, we will not provide neither a power unit nor casing.

As for our stock of the kit, Chiaki has a few bare PCBs and they are tentatively assigned to orders. We have no definite schedule on a distribution of the next lot so far. In the next release, Chiaki plans some improvements.

Bunpei