Signalyst DSC1

Dear Jussi,

First of all, thank you for making the DSC1 project public. Really cool to have people developing interesting projects and making them available to all of us.

I´m ready to have a go at this project but, as requested by other members, we´d love to know if you´re still working on a DSC2 before committing to a DSC1 build!

Could you give us a hint of the states of affairs? We´d really appreciate...

Thank you!
 
Yes, I'm also working on DSC2, but it is proceeding very slowly since I prioritize any software work above the hardware work.

I've been looking for component selections for the most critical conversion parts. Not easy to find the best one that would also keep the cost reasonable...
Jussi, forget opamp, try discete IV with UHF Transistor Arrays. Take a look at intersil HFA3xxx series.

cheers
 

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Boards arrived:

View attachment 520289
View attachment 520290

The parts are inexpensive -- majority of cost are the Susumo RG series 15k 0.05% 10ppm resistors.

Both boards are SMD double sided, the first mostly bypass caps and the chokes that filter each chip. The mirrored version obviously has chips on both sides.

Its going to take some time for me to build, get all the components together to test, needing to build the I-V (sen variant bf862/j111 cascode) and SK filters (jfet buffer based) as well as Salas reflektor-d supplies for digital side, NiCad battery suppies for I-V etc.

View attachment 520291

For reference, the schematics used:
Clock path optimized:
View attachment 520298
Mirrored:
View attachment 520299

Hi Jborden,

is it some progress with this PCB?
 
OPAs etc.

+1 , I dismissed this board due to the use of opamps.

I have never heard a DAC I/V stage using IC opamps which was not bettered by a really good discrete design. But, I am not sure that is what is going on with Jussi's design. I suspect he may be needing to use ICs as high speed switching devices to drive the digital DSD signal. Then the following stage would be the output buffer, and that could be discrete or IC based...

For high speed, on/off switching, a really, really fast IC is going to be the way to go.
 
Hi Jborden,



is it some progress with this PCB?



I've been really swamped at work and with kids activities on weekend -- my son does travel hockey and while I can lots of design etc on my laptop in various hotels, hasn't led itself to working much in my shop :( That said when I get a break from work I am all set to sit down and place all those little SMD parts and then cook the board.
 
I have never heard a DAC I/V stage using IC opamps which was not bettered by a really good discrete design. But, I am not sure that is what is going on with Jussi's design. I suspect he may be needing to use ICs as high speed switching devices to drive the digital DSD signal. Then the following stage would be the output buffer, and that could be discrete or IC based...



For high speed, on/off switching, a really, really fast IC is going to be the way to go.



The idea about cascoding the jFets (cascoded SEN with bf862/j111) should minimize the Miller effect/improve bandwidth. EUVL alluded to that. That said, since we are then going to LPF the output having a higher input capacitance may actually be a blessing as noted by Pass.
 
I'm getting interested in building a Signalyst DSC1 but where to get a board; I don't really want to shell out $160 for three boards from OHSpark.

Has anyone used one of these Chinese boards?

DSC1 DAC DSD Amanero XMOS

And how do you actually buy one anyway?

I have some excellent low noise regulated supplies and would look to repurpose them if I were to go ahead so only need the DAC board.

Thanks