SDTrans 384?

[nige2000]

I have just bought a SDTrans384 after reading the whole DIYAudio thread. Among others, I was impressed by Jonathan Carr (from Lyra cartridges) post stating he had heard the best digital sounds with this transport.
I also have a Soekris DAC and I wonder if it could be used in a similar way to the ES9018 DAC, sharing the master clocks with the SDTrans in sync mode. This is reported to be a vast improvement.

Don't think you can use the Soekris in synch mode with anything - it has one clock from which all timing is derived, AFAIK

But as Nige says, it should be fine to connect I2S into it

Look forward to impressions of the sound

afair

you can take the soekris onboard clk signal as master to feed back to source
not sure if thats worth trying
maybe i should try?

[adolfo.a.aguiar]

I have just bought a SDTrans384 after reading the whole DIYAudio thread. Among others, I was impressed by Jonathan Carr (from Lyra cartridges) post stating he had heard the best digital sounds with this transport.
I also have a Soekris DAC and I wonder if it could be used in a similar way to the ES9018 DAC, sharing the master clocks with the SDTrans in sync mode. This is reported to be a vast improvement.

cool at least we have someone that can do a proper comparison now
what usb to i2s converter are you using on the soekris?
which revision soekris is it?
any mods done?

sd trans should connect up fine with soekris

did i miss a trick with soekris does it work in slave mode?

Hi nige2000,

USB to I2S converter: http://www.diyinhk.com/shop/audio-kits/ ... lator.html.

Regs: http://www.diyinhk.com/shop/audio-kits/ ... 15ax2.html and http://www.diyinhk.com/shop/audio-kits/ ... 15ax2.html

Soekris latest version. Some parts still missing. Will do the mods as per randytsuch blog.

[gstew]

I've got one of these working with a Soekris DAM right now, sitting next to it and connected via I2S in my digital source test setup. I'll post pix tonight or tomorrow. It should also work nicely over a short distance via S/PDIF and if you wanted to locate it remotely from your DAM, you could use the PS Audio-compliant HDMS LVDS I2S output and hack/wire it into a Twisted Pear Teleporter at the other end. But my guess is a short I2S connection will sound the best and it is likely a sufficiently low-noise and low-jitter I2S source that bypassing the DAM isolators (which will of course add some noise AND jitter just by doing what they do) will make a positive difference.

I have not listened to it critically nor in my main system, so I can't comment on SQ. And based on some of the comments from the main SDTrans384 thread and some related to it (including some from Jonathan Carr, designer of the Lyra phono stages and cartridges), it is supposed to be as good as any other digital source out there.

And I think it will be an absolute PAIN to use, with music only on SD cards. I'm slowly copying (and de-FLAC'ing) the core music from my library onto cards. Beware, they tell you some cards don't work in the device. I found that out, with 32Gb Samsung working ok, but 16Gb ones did not. Try before you buy a bunch... I didn't!

I don't expect I'll get off the computer player source train entirely, but plan to use this more like I've used my turntables... when I REALLY want to listen, it is where I go. The rest of the time, I'll use my easy-access sources.

My DAM is just running this week and still very stock. This will be my reference setup while modifying the DAM (thanks for all of the great info here, BTW).

Greg in Mississippi

P.S. Rick, I wondered why you were selling your USB card & cable. Makes sense now!

[jrling]

I have just bought a SDTrans384 after reading the whole DIYAudio thread. Among others, I was impressed by Jonathan Carr (from Lyra cartridges) post stating he had heard the best digital sounds with this transport.

I also read a post in that thread from 'elecon', Stig Bjorge from Norway who is the owner of Lyra - Jonathan Carr's Boss. He said it was the best digital player he has heard.

Not half bad references.

Jonathan

[gstew]

you can take the soekris onboard clk signal as master to feed back to source
not sure if thats worth trying
maybe i should try?

Nige, is this working? I seem to remember hearing different opinions on that.

Greg in Mississippi

[jkeny]

I have just bought a SDTrans384 after reading the whole DIYAudio thread. Among others, I was impressed by Jonathan Carr (from Lyra cartridges) post stating he had heard the best digital sounds with this transport.
I also have a Soekris DAC and I wonder if it could be used in a similar way to the ES9018 DAC, sharing the master clocks with the SDTrans in sync mode. This is reported to be a vast improvement.

Don't think you can use the Soekris in synch mode with anything - it has one clock from which all timing is derived, AFAIK

But as Nige says, it should be fine to connect I2S into it

Look forward to impressions of the sound

afair

you can take the soekris onboard clk signal as master to feed back to source
not sure if thats worth trying
maybe i should try?

What is the speed of the Soekris clock?
The SDTrans uses the usual recommended clock configuration of two clocks for audio playback.
The Soekris clock may be possible to feed back to a Sabre DAC where all signals are upsampled internally in the DAC chip & clocked using one PLLed clock but this isn't the best arrangement for optimal sound

[gstew]

<SNIP>

why is this board supposed to be good?

Nige,

My take...

1. Very simple processing in the FPGA, limited types of files, no data transformation, no reclocking, just take what is on the card and feed it out as an I2S signal, so minimal noise created in playback.

2. Good use of the hardware and board layout. The clocks are close to the FPGA, it only outputs I2S, this goes directly to the buffer chips for direct output, to an LVDS chip for the PS Audio HDMI output, and to an I2S->S/PDIF conversion chip (Cirrus, as I remember).

3. Reasonable distribution of power regulation right at the local consumers along with good filtering. It's a plus that you can power all of the sections separately for higher performance.

But it is basically just a digital turntable, no metadata, having your music only on SD cards, and some care has to be taken to keep from corrupting them (from the manual, don't turn off or eject the cards while they are being accessed). It is not as convenient or as flashy as most computer digital playback. I'm good with that, but am finding the process of loading SD cards a bit of a pain.

Greg in Mississippi

P.S. I got mine on the tail-end of the last GB, it was the base unit without the upgrade caps (on the picture of the back of the unit that has been posted) and no remote. It cost me about $350 USD, with the GB discount.

P.P.S. If you think all the battery powered stuff you guys do is viewed as crazy, take a look in the later posts in that thread on how they experimented with setting up a light-powered source for the SDTrans384... shine bright lights onto solar cells to power the unit!

[jkeny]

Excellent to see that there are a number of people now on this thread who have the SDTrans - makes for much more interesting discussion & possibilities.

I didn't read the complete SDTrans thread on DiYaudio just dipped in & out of it & didn't register the provenance of those LYr posts - impressive recommendations, indeed. I wonder what digital systems that had heard previously?

The reason I say this is because at recent meetings a group of us, including Nige, Tony, Sligolad, Ken & others have heard some digital playback which is much more refined & analog like than anything we have heard before. Mind you, this is using a heavily tweaked PC system with audio-grade :) OS & playback software, USB cables through an Intona or Regen & a heavily tweaked Soekris DAC.

Now, if the SDtrans can replace all this it would certainly be very worthwhile despite a UI which is not user friendly some inconvenience with SD cards.

[jkeny]

<SNIP>

why is this board supposed to be good?

Nige,

My take...

1. Very simple processing in the FPGA, limited types of files, no data transformation, no reclocking, just take what is on the card and feed it out as an I2S signal, so minimal noise created in playback.

2. Good use of the hardware and board layout. The clocks are close to the FPGA, it only outputs I2S, this goes directly to the buffer chips for direct output, to an LVDS chip for the PS Audio HDMI output, and to an I2S->S/PDIF conversion chip (Cirrus, as I remember).

3. Reasonable distribution of power regulation right at the local consumers along with good filtering. It's a plus that you can power all of the sections separately for higher performance.

But it is basically just a digital turntable, no metadata, having your music only on SD cards, and some care has to be taken to keep from corrupting them (from the manual, don't turn off or eject the cards while they are being accessed). It is not as convenient or as flashy as most computer digital playback. I'm good with that, but am finding the process of loading SD cards a bit of a pain.

Greg in Mississippi

P.S. I got mine on the tail-end of the last GB, it was the base unit without the upgrade caps (on the picture of the back of the unit that has been posted) and no remote. It cost me about $350 USD, with the GB discount.

P.P.S. If you think all the battery powered stuff you guys do is viewed as crazy, take a look in the later posts in that thread on how they experimented with setting up a light-powered source for the SDTrans384... shine bright lights onto solar cells to power the unit!

Hehe, we know we are crazy but we have our limits & every now & then we take stock of where we are & ask "how did we get here" :)
We have always maintained that we shouldn't be using a PC as the start point but so much progress was being made on this front that it's hard to get off that particular path & start a new one

This may be the crossroads - some testing & auditioning will tease this out but I also expect that our experience with the PC audio mods so far puts us in good stead for improving a SD card player - Let the games begin :)

BTW, I agree with all you say - the design principles of that board look right - it's just down to implementation details but in looking at it there doesn't seem to be any issues there either?

[gstew]

you can take the soekris onboard clk signal as master to feed back to source
not sure if thats worth trying
maybe i should try?

What is the speed of the Soekris clock?
The SDTrans uses the usual recommended clock configuration of two clocks for audio playback.
The Soekris clock may be possible to feed back to a Sabre DAC where all signals are upsampled internally in the DAC chip & clocked using one PLLed clock but this isn't the best arrangement for optimal sound

JKeny,

The Soekris clock is variable and adjusted to make his short I2S FIFO work, but the output will be close to the standard 45/49 frequencies used for the 44.1 and 48 sampling rate families, depending on which family is being selected.

I doubt it varies far from the standard clock frequency.

OTOH, I doubt taking the higher-jitter clock from the DAM across the isolators and then across wiring into the SDTrans will improve on their lower-jitter NDKs directly connected. I could be wrong, but this is not an experiment that is high on my list.

You CAN use external clocks on the SDTran easily enough. I vaguely remember one of the implementation of the pricey Pulsar clocks was on an SDTrans... I bet it was transcendental!

Greg in Mississippi