I've built a arduino / uC 4bit synth simular to LSDJ's wav synth. I will say that pumping bits through usb serial from a max4live patch would work, but I think it will not have that sound you're looking for. Rough form field math tells me that at a serial rate of 115200, you'll get a rate of 11,520hz mono 8 bit signal. Without any nice filtering or logic I'd imagine it'd sound pretty bad.
You're better off doing what nitro2k01 said and just do a nice bit degrade. Even better would be to use Ableton's sampler (not 'simpler') or Renoise and turn off interpolation, along with a bit degrade that might yield pretty decent results.