[sdiy] poly cap replacements, diodes, transistors

[Tony Allgood]

>Buchla used "poly" (styrene?) caps, packaged in white plastic boxes
about roughly 1/4" X 3/4" (top view).

They may be only metallised polyester... but I have seen polystyrenes in
this sort of case in old TV sets from the late 70s. Most of the old
polysytyrenes I know have clear axial bodies where you can see the
silver foil inside, others have a sort of grey-green covering that looks
like it has been covered by dipping.

>Their values are given without units, i.e.  .18.

Most likely 0.18uF or 180nF.

>What would be a reasonable replacement?

I would go for polyester film... but some parts like VCO timing caps
will be better replaced by polystyrene.

>MM5837

Infamous noise generator chip. Try your local organ repairer, he should
have some left.

Regards,

Tony Allgood, Penrith, Cumbria, England

Oakley Modular Synth and TB3030:
www.oakleysound.com/projects.htm
My music: www.mp3.com/taklamakan