> Is it possible to install buchla modules into a serge system?
It depends what you mean, Physically put them in the same boat or
make a system with separate rows of each module and then patch them.
Serge really isn't a modular in the old school sense where you buy
and add modules one at a time to your rack... and as mentioned even
though their heights are both 4U, the power requirements and
connectors aren't the same.
BUT...
That shouldn't stop you entirely, Buchla currently offers a variety
of small boxes, racks and boats. Considering the price of the modules
(M-odules) I'd certainly not want to power either by some makeshift
means, not that that was necessarily your plan. If you can afford a
259 I'm sure you can afford to power it properly.
Buchla does use some different standards that Serge likely
encountered and decided not to use. As mentioned, Buchla is 1.2 v/
oct. It's not that bad to overcome it if Volta isn't your thing (and
volta only claims to semi work with Buchla, which is a whole other
topic as well as the 200e is partly but not exclusively designed to
work with MIDI). Anyway Buchla to Serge just means you need an
attenuator. (Can be built yourself, the second simplest module after
the multiples) and some time to scale it. Serge to Buchla needs a
mixer that can handle DC voltage - you know the kind on most
modulars. You mult your voltage and send one to a mixer pot wide open
and send a second to a mixer pot that's 20% open. A bit of adjustment
and you have 1.2 v/oct. If you want to deal with a MIDI keyboard and
not with Volta, 1.2v/oct is within the scaling range of some MIDI to
CV converters but not all, just ask the maker if it can scale 20% up
for 1.2v/oct.
Another complexity not mentioned is a Buchla gate is a 10v trigger
ORed with a 5v gate (OR meaning it's still 10v when combined). It's
possible to deal with that in a couple ways.
Another complexity is a lot of Buchla doesn't respond to negative
voltage.
Finally Buchla audio and CV are very different levels and aren't
freely combined like Serge decided to do. So you'd need to amplify or
attenuate your cross system audio.
Definitely not impossible but not "plug and play".
> Or what about clones?
It depends if you are talking about clones built to drop into a
Buchla system - obviously the same rules apply, or the DIY clones?
or the more or less clones meant to fit in other formats like Euro.
> What are the options? Can new 200e modules be installed?
The 200e modules have a data bus and send messages to each other. You
don't have to use it but then again it's a major innovation of the
200e (that's why there's an "e" in it and Buchla still makes two 200
series modules without the 200e feature set.
Buchla offers some quite decent options if you just want 2 or a
rack of 4 200e modules that will also power most 200 modules
Nick