Output Quality...

Well the advantages of using a processor with on board DAC and ADC is it is well integrated, cheaper and simpler... Down side is that the DAC is only 12bits and using an ADC on the same substrate as a lot of digital logic is always going to be a compromise. To see what we are getting out of this baby I have made a digital oscillator in the code that is A440 and it is independent of any analog input control so we are just testing the DAC. It looks fine on the Oscilliscope:

However having a look on the Spectrum Analyzer shows that there is a moderate amount of noise there:

So a after having a fight with the torturous UI of the spectrum anaylser the signal-to-noise is about 45dB rms. This isn't too bad as the theoretical best for a 12 bit converter is about 72dB (6dB a bit) and reading the datasheet we see that we have an INL of +-8 LSB so probably what we would expect... The software currently just prunes off the bottom 4 bits, we could do a nearest neighbor and also accumulate the error to perhaps push it a bit closer... The distortion comes out at around 0.5% which compares quite favorably with the sinewave accuracy of most Analog VCO's output from transistor curve sine approximations...

How does it stack up against the original? Well the original Braids has a external, rather nice, high quality TI DAC. I don't have one available to measure but your going to have to be 20 to 25dB better off... But it's not all that bad when you consider the Oscillator is designed to be +-5V out in most modes and the filtering and dynamic processing is down stream in the VCF/VCA chain. It is more the modes which do physical modelling that it will be more noticeable. The Orgone Accumulator actually runs on the same family (albeit the M4 version) and uses the same internal DAC.