so, that last post got my mojo workin…. a quick note is all i’m going to drop here. if one was to add a mid cut filter and buffers, here would be a way to do it, this will be the lowest noise version. a simplification would be to dispense with the last buffer. then add a second “gain” pot and you could use the “saved” section of the 12AX7 as an extra gain stage and deal with the highZ output (bad with long cables). madness.  still, this is a distortion box and they are all, by definition, noisy. ever use a big muff? then you already know… as is, 100mV in should give you 100mV of death metal out. a one meg pot will back it off. the mid cut is real muff style and will mess things up appropriately. here are the waveforms at 1KHz and 200Hz…

ok, i should stop. but here is the added extra stage arrangement… not as well behaved as the first one. but it has adjustable output level. you may not care. these are some of the techniques one can begin with to make interesting distortion effects.  this is enough.