the elephant in the room to ignore the multitude of problems posed by connecting a computer to the audio system. I've always stressed that the RF and Jitter should be dealt with BEFORE they are allowed to enter the DAC enclosure - this holds true for the MDAC and FDAC.
The design is a quick task, the production will be interesting, but I'm really keen to "send a simple design down the production line before the FDAC PCB's" so it makes this little project even more interesting.
If there is significant interest then it will take less then a week to design the PCB.
As each USB Hub device only offers a certain "limited" level of attenuation I'll cascade 3 devices in series each with there own PSU and Clock interface, this will add extra cost - but its the correct way to design the board.
Lets to a proper job of this
I'll use these RF screen tins for each Cascaded attenuation stage and the Master clock circuit:-
http://www.teko.it/en/prodotti/famiglia/RF/serie/49
So the design will look something like this:-
......
Development fee GBP50 + unit sold at cost say around GBP80 payable once we start to manufacturer the PCB's.
If we have say 20 PFM'ers interested then I'll launch the project and spend an hour or 2 designing the PCB each night.