While hooking up my under $20 oscilloscope that I found on sale at Amazon an idea struck me. No, I didn’t accidently come into contact with mains. The idea was that the DAC in the Daisy could be easily programmed to be an audio oscilloscope and you could get it to display old school synth art like spirals and such (this gave new meaning to ring oscillators in the 1970’s). Plotting audio frequency on the horizontal plane would yield a frequency spectrum analyzer. A few more modifications would capture frequency domain. That could be used as a near real time waterfall display. Link this to the high res display of a desktop or laptop and you have a serious device. I think this would be cool stuff, do you, or am I missing something that would spread poo on the idea?
A better question seems to me to be “why not?”
I’m uncertain of the particular exact specs of the Daisy, as far as THD, noise floor, and other potentially important specs for true “test instrumentation” but that would be the only concern. A few people have reported noisy outputs BUT it seems likely that was due to questionable builds, i.e. wedging power regulators/supplies next to the ADC/DAC inside compact eurorack formats and/or grounding issues. With proper shielding and gauss field mitigation… getting out of my depth here.
For audio purposes it’s absolutely enough. The most work would be creating nicely isolated and protected probes as well as designing visualization to be usable on a tiny screen. If you need a standalone battery operated “field” scope, that’s a nice project. At home, a PC would be an easier platform.
However, if combined with a signal generator and some analysis/capture features it could be cool. From simple cases of capturing room/speaker/… impulse responses to more advanced one like guitar amp “profiling”.
Regarding frequency domain, I have a half-done spectrum analyzer code lying around somewhere. I can consider finishing it and open-sourcing. Until then an FFT would have to do the job.