I am not currently selling assembled hardware so you will need to arrange this or build boards yourself. This may change if there is enough interest in the project. See below for a little information on building and using real hardware.
Getting design files
All design files are hosted on github at github.com/ohdsp. Each repository contains KiCad files, manufacturing data and PDF and SVG formats of PCB and Schematics. A Gerber zip file is ready to be sent to a PCB fab house.. There is also full bill of materials, and some pick and place/stencil files for assembly.
To view files just download, or view online from the repository as you wish. To use KiCad head over to the KiCad website and download the version for your operating system. Once Installed download KiCad-Libs from github, the readme.md file has instructions on how to set this up. The readme.md files in each repository has information on how to download the data and use it in KiCad.
Note that with the introduction of KiCad 5 and newer, if you download an older project you may need to remap libraries when opening a project.
Building and using real hardware
To get real hardware you (or someone) needs to build real hardware. Arranging a group buy of fully assembled boards may be a good option. I would be happy to do this with enough interest. So far I have been having success hand soldering with a normal 3mm chisel bit including the ADAU145x LFCSP parts. The large via under the device make this possible and quite easy to do.
I have been using DirtyPCB to get PCBs made, the quality of both 2 and 4 layer PCBs is very good given the low cost. Four layer boards are designed for a specific stack-up (0.2mm prepreg, 1.2mm core). I am sure the boards would still work if this is not followed but have not tested this.
If you make a batch of blank boards and don't need them all you might be able to sell them off to other people or arrange it as a group buy to start with.
What hardware and tools do I need to hand build?
All of these boards are SMD parts. I do not have the best soldering skills in the world but I have had a fair bit of practice. If you wish to try out SMD soldering cheaply with no risk then get some strip board (vero board). Buy some cheap 0805, 0603 resistors/capacitors (just some 1kohm and 100nF parts), and something tricky like some BC847 SOT-23 transistors. Try soldering them to the strip board. It doesn't matter if they don't line up or short out, or burn to a crisp, it will cost less than a few pounds/dollars and lets you get a feel for it.
To build a system from bare PCBs you will need:
Blank printed circuit boards. This could be anything to make the system you want, within the limits of the hardware. For example to give a system with 2 analogue inputs and 16 analogue outputs:
A 2 channel ADC board - The PCM4202 would be ideal (Single ended or Differential version)
An DSP board - The ADAU1450/1451/1452 design is very powerful
An 16 channel DAC board - The ADAU1966 board gives you 16 differential analogue outputs to play with.
A power supply of some sorts - boards generally need 5V and +/-9V supplies, you could test this with some PP3 batteries and a 7805 if you are desperate. The PSU board is a neat safe solution that works with a 9V AC output plug pack/wall wart or any 9Vac output trasformer if you are skilled with mains wiring/safety.
An EVAL-ADUSB2EBZ or equivalent device for programming the DSP board, or an XMOS XA-XTAG for CoreOne
All components (mostly SMD parts) to populate the boards for the functions you need (you may not need everything!)
A soldering iron (several size tips are useful)
A magnifier or loop
A computer (windows or windows in a virtual machine) with SigmaStudio (DSP) and/or xTIMEComposer Studio (CoreOne)
Useful additional accessories:
Flux (no-clean type)
Flux cleaner (you can never have enough flux, just make sure you clean it off again)
A current limiting DC supply is good for newly built boards
Some audio kit
Cabling/wires/phono plugs etc
Hot air or SMD rework station (will make life easier)
The will to do great things and not give up!
If you are into electronics and audio electronics you may have most of this already.