[sdiy] Modding the MKS-3(7?)0 - Looking for suggestions

[Colin f]

> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl 
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of 
> bayne d'artagnan
> Sent: 12 October 2007 17:31
> To: .
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] Modding the MKS-3(7?)0 - Looking for suggestions

> Not to mention the fact that the IR3109 is a MUCH better 
> sounding filter.

The IR3109 is a quad OTA.
It's flexible enough to make a great sounding filter (JP8, early Junos, 101
etc), or it can make a rather weak dual-series SVF (JP6, MKS80 rev 4).
Looking at the progression of Roland filters over time, it looks like IR3109
may well be a quad BA662.
Earlier Roland synths use 4 x BA662 integrator stages for 4 pole LPF (Sh09,
System 100M).
Then they progressed to the 4 stages of an IR3109 as 4 pole LPF (JP8, SH101,
Junos 6/60).
Then the Jupiter 6 appears, with IR3109 configured as a pair of SVFs. Ugh,
IMO.
Followed by the JX, MKS80 rev 5, Alpha Junos etc. with IR3R05 - a pair of
SVFs with integrated VCA (apparently the JP6 SVF integrated with a VCA for
output, and VC resonance.

Cheers,
Colin f