[sdiy] Blacet Improbabiltiy Drive build report

[R. Drake]

Got my Improbability Drive kit yesterday and completed it today... it is
sweet!  Analog noise is as you'd expect; "digital" noise is derived from the
analog via a comparator (richer than the usual shift-register digi noise,
plus VC of the comparator, and the "mix" lets you pan seamlessly between
analog/digital); then a 2-mode filter (w/ VC); then the Sample/Hold with
internal VC clock, and finally a 4-mode quantizer!  The variety of
possibilities, and the musicality of this as both sound and control source,
are really inspiring.  I played with it all afternoon and still felt like
there was more to discover.

I built mine with one mod: stock, the quantizer modes (chromatic, major,
minor, & diminished) are set by a trimmer on the board... i brought that
control out to the front panel.  I sacrificed the VC jack of the internal
S/H clock (figured if I needed that feature, i could patch in a VCLFO as an
external clock)--happened to have a surplus clarostat pot w/ a 1/2" round
body, fit perfectly.

I also wanted to add an tap into the quantizer, so I could feed an external
signal thru it... seemed simple on the schematic, but the pcb looked like it
would be a tricky surgery cutting tracks, so i skipped it.  Panel
real-estate for another jack would also have been an issue.  If John ever
does an MOTM version, tho, I think there would be room for both these added
features. 

This is really a great time for analog/modular synths--so many cool tools
available.  My wife and my pocketbook may scowl, but i'm thanking you all.
Back to the basement!

bbob