[sdiy] help finding roland filter schematics?

[Olav Martin Kvern]

Dan Snazelle wrote: "in my quest to better understand OTA filters...."

I don't know about Roland filters (maybe I should change the subject line?), 
but I've been following your questions about OTA filters, and it sounds very 
similar to my experience. I've been wondering--have you built the examples 
shown in the datasheet/application notes for the LM13700? I found it 
incredibly helpful to get those examples working before I moved on to more 
complex circuits. Building the circuits without voltage controlled 
resonance, for example, would probably help isolate the problems you were 
having with that feature. Then I'd look at the excellent--but relatively 
simple--SEM-style circuits from MFOS and Takeda-san.

Just a thought--this approach helped me a lot when I was learning OTA 
filters.

Thanks,

Ole