the 4012 was a transistor ladder "moog" filter and doepfer already has
that (A-120) so go for the 24db (cascade of integrators) 4072 or 4075
(these two are almost identical)

/A

> The 4012 was probably the best known. Other ARP classic VCFs are

the

> 4035 and 4072/4075. There's schematics and info at:
> http://www.till.com/arptech/modmain.htm