[sdiy] Untangling the Oberheim OB-8 filter

[Tom Wiltshire]

On 12 Jun 2017, at 10:46, Elaine Klopke <functionofform at gmail.com> wrote:

> This is really cool! So can this be replicated with OTA chips and op-amps instead of the 3320?

Yep, absolutely. You could use LM13700 and an op-amp buffer (or a FET buffer) and you'll find plenty of schematics that do. I'm sure the MFOS site has one, for example, but many of the early Roland synths have other examples.

For me personally, it was timely, since I've now got a pile of the Erica Synths/Alfa Rpar AS3320 filter chips (a CEM clone) in the shop, so I thought I'd play with those. I think a Elka Synthex filter might be in the offing…

Tom