Open letter

[Sean Costello]

tomg wrote:
> 
> > That's not true Don. I have asked for permission from everyone I
> > could contact. Bob Moog, John Blacet and John Simonton to name
> > some. If you know who to contact for arp and ems I'll be glad to try
> > and call. I guess I should actually call Korg hadn't though about
> > that one.
> 
> Peter says EMS is still around. I have offered to remove anything
> they object to. So we'll find out about this one too.

Well, your "EMS" circuit is in no way a clone of the filter in the
Synthi/VCS3.  The EMS circuit uses all transistors for diff amp and
such, while your circuit uses op-amps.  There are lots of other
differences. Besides, there were several other synths that used the
diode ladder, so EMS can't claim ownership. Especially since all of the
diode ladder circuits were taking advantage of a loophole in the Moog
patent.

Sean Costello