HiRes SD Card Player: SDTrans192 v. 3.0
Mr. Bumpei was kind to let me try his hi-res memory player. Installation was straight forward: a 5V supply and 4 wires to connect the I2S output to the Buffalo II DAC.
Using it is also straight forward: copy some WAV files into a SD car and plug the SD card into the SD slot and press the play button. There is a 2-line display indicating the track name of the song that is playing
The unit has SPDIF out and HDMI (or what it seems like HDMI) output [it is a PS Audio type of I2S interface through HDMI wiring], but I only used the I2S connector. For the Buffalo II DAC I did not hookup the master clock as Buffalo has its own clock. You can find more info here: http://www.chiaki.cc/Transport/sdtrans192.html
The board also has connectors for remote control and I2C control. That means you can use an Arduino to control the board. I am not sure how much functionality is provided through i2c, but there is a lot of potential for integrated this device into an Arduino environment. For example, if you are using Arduino to control the Buffalo DAC, you can also control the SDTrans allowing full track control and volume control from a single remote.
The clocks are generated by a couple of external oscillators, each used to generate the 44.1K or 48K families of frequencies
The output sample frequency is exact (as deteted by the Sabre Buffalo II DAC DPLL)
I first tried to set the DPLL setting to “lowest”. And just as it has been reported elsewhere, I experienced unlocks with this setting in a similar fashion as other I2S sources I have tested. So I used “best” for trouble free operation. This behavior with “lowest” DPLL setting is definitely a “design feature” in the Sabre32 DAC.
I used a 7805-type regulated supply to power the SDTrans. Not the best linear supply out there, but the local regulators are of low noise type (see photos below). There is a report indicating that upgrading the local regulators on the board would enable the use of “lowest” in the Buffalo II’s DPLL setting.
I loaded a few tracks that I am familiar with into the SD Card. I selected mostly 44.1K tracks and some 96K/24 tracks. It was real easy to generate WAV files from my iTunes AIFF files (a one-click operation after setting the import format to WAV). I was very satisfied with the sound. Definitely not worse than my current setup (how can it be).
With some extended listening, I felt some tracks offered more “sparkle” and clarity. But mostly the sound was familiar in all respects. A big part of sound course is the Buffalo II DAC and the fact that it uses ASRC with its own high quality clock.
I like very much the fact that the SDTrans can boot up in a couple of seconds and can play tracks for different sample rates in bit perfect mode. Although you are limited to the size of the SD card, one can select a collection of favorites and let it play sequentially from beginning to end. Definitely a much simpler set up and higher quality playback than a PC based music player.
Another plus is its ability to play content beyond 192K. I shall try some of the tracks from 2L…