audio-talk

I've now taken delivery of my Soekris 1121-01 R2R DAC board. First impressions after unpacking it are of a very nice neat board that seems to be a high quality product. There are an awful lot of tiny smd parts packed onto this small PCB.

http://www.soekris.dk/dam1121.html

I will feed I2S signals into the R2R board courtesy of a JLSounds USB board. This features galvanic isolation (from USB noise) and reclocks the I2S output so the DAC will receive a good quality data stream. The JLSounds board is really good and excellent value; I've used them in several previous projects with consistently good results. If you're currently running SPDIF into a DAC that has an I2S input option I suggest you check it out.

http://jlsounds.com/i2soverusb.html

I have also ordered some very low noise regulated power supplies courtesy of AckoDAC that will soon be making their way from down under, and an AudioZen control unit (takes care of volume, filter selection etc and uses a small OLED screen to show the DAC status) that's currently on its way from China.

I'm currently working on a small PCB that will connect the JLSounds with the Soekris (it provides the I2S and comms. interfaces as well as setting the initial startup config. straps. I'm ordering a customised case from Modushop in Italy, The they'll be a short hiatus while all the various bits make their way to Taunton.

The Soekris output is a single-ended, unbuffered 1.4V and initially I'll feed that to my amps but the plan is to then experiment with valve based buffers as that seems to be the way to go from others with experience of this DAC. I am planning to start with a Broskie Aikido buffer using 6SN7 octal valves and to then try a #26 DHT buffer (the chap who worked with me on scratch building the Transcendent 300B SE-OTL amps that I brought to Owston has gone down a similar route and gives it a very strong endorsement).

More to follow when I have something to report.

Ray

Maybe I should have started this thread in the projects section? Oh well...

Sounds like a really nice project Ray.

Ray P wrote: ↑Tue Jul 18, 2017 9:37 pm Maybe I should have started this thread in the projects section? Oh well...

Do you want me to move it?

I am really interested in this. I'll be watching with interest!

Nick wrote: ↑Tue Jul 18, 2017 11:54 pm Do you want me to move it?

Thanks Nick, I think that's where it really belongs though I wouldn't want to put you to any great trouble.

Ray

Bigman80 wrote: ↑Wed Jul 19, 2017 2:39 am I am really interested in this. I'll be watching with interest!

Can you turn down the volume on your strap line please, it's really distracting. Thanks

Ray P wrote: ↑Wed Jul 19, 2017 6:28 am

Bigman80 wrote: ↑Wed Jul 19, 2017 2:39 am I am really interested in this. I'll be watching with interest!

Can you turn down the volume on your strap line please, it's really distracting. Thanks

Sorry, Ray. I don't know why it was so big!

Bigman80 wrote: ↑Wed Jul 19, 2017 6:34 am Sorry, Ray. I don't know why it was so big!

I suspect you need to edit your signature to change the font size, you'll find it in your profile settings.

I found it Ray, thanks

Still waiting for components to arrive so not too much progress but I've finalised the interface PCB and have started working on the drawings for the chassis. Hopefully r=things will start to arrive this week.

Ray

I've finally started to assemble my Soekris DAC.

Like Dave and his 'Dieselpunk Preamp of Doom' my starting point was Front Panel Express except I purchased a chinese chassis and then sent parts of it to Germany for machining - They always do a good job, if at a price...

Having received the panels I've started by assembling and installing the AudioZen control unit - this is specifically designed to control (volume, filter selection, mute, input, etc) the Soekris DAM1021 and DAM1121 DAC modules and is available from the Vendor Bazaar at DIY Audio.

So, here are some pictures of progress so far. The control unit is installed and working.





A more general layout image showing the Soekris DAM1121 module and the JLSounds USB board. The two Black PCBs are for the power supplies for the Soekris and JLSounds modules; they'll be next to assemble and install. The large empty area is where a Broskie Aikido (ACF-2) buffer will be located.

I had planned to build the PS boards and power up the Soekris board this weekend but with my back injury I can't comfortably sit at my work bench; I don't want to be distracted into making an error so progress will have to wait for a few days.

I've picked up the project again now I'm feeling a lot better.

A question if I may: I'll be using a Broskie ACF-2 buffer stage on the output of the DAC and I want to power up the ACF-2 in sequence, heaters first then HV some period later. The problem is that the ACF-2 uses a bipolar HV power supply



but the delay circuit i have can only swith a single pole. I believe the answer is to use the delay circuit to swith the centre tap of the HV supply but thought it best to let the experts amongst us confirm or point me in a better direction.

Cheers

Ray

I've been making some soli progress with my Soektis DAC project today. Getting close to completion but still waiting for some PCBs to be delivered to interface the DAC with the USB board.





Everything tests out so far. 'll get everything ready for final hookup tomorrow and then I'll just have to sit on my hands.