yeah, am considering the option of just manually setting once the ramp finishes.  But considering that i'm off by about 0.1% every 44100 samples, it's a bit worrying.  Would be ok for synth envelopes, etc...but i'll probably want to use this to lookup audio file tables, etc too, in the future, so kinda want to get it spot on. 

right now, the performDSP function is literally a single conditional and then += increment, which seems nice and lightweight.  i'd like to aim to keep it as close to that as possible...