[sdiy] Why no Roland filter clones?

[Terje Winther]

If I am wrong in this, please direct me to the correct answer, but...
Why is there no modular filter clones of Roland VCFs? (I know that  
there are many TB-303 clones)
There are a lot of filter clones from famous manufacturers/synths,  
like Moog ladder filter, Korg MS-20, VCS3 filter, Yamaha VCF, Oberheim  
clones, Wasp filter etc., but I have (so far) not come across any  
clones of the Roland SH-series VCFs or other Roland early filters  
(except for the TB-303 clones).
These Roland filters were mostly made with CA3080s and/or transistors  
so they should be fairly easy to copy. The later analog Roland synths  
started using custom chips, like the IR3109 chips etc., but the  
earlier synths have ordinary VCFs that sounds great.
There might be a copyright side to it that I am not aware of, but none  
of the bigger brands (doepfer, MOTM, Oakley, synthesizers.com, Blacet  
etc. etc.) seem to have anything like the Roland filters, but lots of  
other (good and interesting) filters.
So why is this?


Terje Winther
terje.winther at wintherstormer.no
http://www.wintherstormer.no/