I believe the email below I received was probably meant for the entire list.
> From: the_real_dripfeed
> Jürgen Haible's "Living VCO" was his attempt at reproducing
> the 901's character in a stable form. But they are pretty
> rare now since Jürgen's death, and his designs being
> mothballed with his estate mean that 3rd parties can't
> manufacture them under license.
>
> http://www.jhaible.com/living_vcos/jh_living_vcos.html
>
> Have you tried injecting a bit of character into your
> current oscillator by adjusting or modulating the
> Volt-per-octave input slightly so it doesn't quite track?
> Layer another stable oscillator on top and Bob's your
> uncle.
>
> Re: all oscillator waveforms sounding the same. That is
> definitely true if the samples are just a solitary note. But
> all oscillators I have owned sound different to each other
> when played over a few octaves, especially using square
> waves.