Project Mono! THAT1286 & CS5381 ADC

[limacon]

Morning all!

I've just about assembled "Project Mono v0.1" - a mono ADC board.

Featuring

+24dBu input signal
THAT1286 wired in anti-phase per channel
24dB resitor pad for approx -128.3dBu noise into ADC
Subtraction mono in DSP should provide a further 3dB noise reduction
OPA1611 VQ buffer
74VHC125MT & NC7SZ125M5X digital buffers
I2S slave, quad speed mode, high pass filter on
6V DC supply
Ultra low noise 4 channel regulator providing analog and digital rails

DHL should be delivering the THAT ICs today. More to follow!

 

[limacon]

Installed THAT1286. Testing time.

 

[dddac]

nice, what UI are you using it with ?

 

[limacon]

Also testing a 2.5-6V upto +/-18V regulator for about 200mA. I've dropped in SBCP56 transistors with 100uF caps to form a capacitance multiplier. I'll be checking the noise later on the Digilent.

 

[limacon]

nice, what UI are you using it with ?

UI? Not sure I follow your question.

 

[dddac]

User interface. Sorry

 

[limacon]

Do you mean DSP hardware and software?

 

[dddac]

Yes, let’s put it in this way, after the a/d conversion you want the data to go somewhere as track in some kind of format….

To be honest, I did not research this topic extensively, and used occasionally typical window recorder stuff, but that was not very convenient for digitizing a LP for example….

 

[limacon]

Right! The plan is to use the I2S output from the CS5381 into my own design DreamDSP based main board, connected to a Mac via USB.

 

[limacon]

PSU bench test reports to follow shortly. I've been changing out caps and beads in a bit of trial and error to improve input and output EMI filtering and have now settled on a BoM.



Next task is to minify the board and test again!