Re Doepfer in keys on filters

Tim Cockram tim at
Fri Sep 20 00:07:34 CEST 1996

Well, Mr Doepfer is sort of right. Bob Moogs filter uses the transistors as "transdiodes" which are for all intents and purposes 
well behaved diodes.  Roland in the 303 and I belive EMS in the VCS3 etc used the plain old diode to get arround the Moog
Patent which specificaly mentions the use of transistors ( Shame for Moog that his patent attorneys didn't just say Semiconductor

Despite being sort of right in his analysis  Mr Doepfer should also  have said that for some inadequately explained reason the filters don't
sound the same (don't take my word for it try it and hear).  To me the EMS filter sounds  er "mushy" whilst the 303 filter is just 
not very refined or meaty(so much for quantative analysis).


More information about the Synth-diy mailing list