i made another distortion circuit. this one is very stable, and very loud. based on my limited understanding of the subject, this one works by overdriving the components inside the opamp, rather than using a diode to clip the peaks of the waveform. despite how primitive and brutal this circuit is, it doesn't do much self-oscillating, and actually gates a lot of low-level signal, which is a good thing when dealing with amps and guitars.
actually, the gain is so high on the output that i believe it will need a third opamp to attenuate the signal, because otherwise any guitar player who uses it will most likely just destroy their amp.
to test this and future pedals i'll be using an actual electric guitar, since the impedance isn't quite the same coming from a contact-mic'ed kalimba. it's an american strat-- not mine-- and i have almost no competence with the instrument anymore. regardless, i refuse to tune it, because i really like the sound of a well-detuned guitar.
this pedal currently has no knobs or switches; it can only be on or off. eventually, a volume control and wet / dry knob might make an appearance.