> Hi,
> I was wandering if it was possible to build a configuration which has the same features as a morphing filter a-107. What
> would I need
> Thanks in advance.
> Regards,
> Danny.
That's possible but requires a lot of stuff:
A 4 stage filter with the four outputs: 6 dB, 12dB, 18dB and 24dB (e.g. A-108), two inverters (because for two of the outputs the
inverted signal is required), four VCAs to mix the four signals, a unit that generates the control voltages for the different filter
types (in the A-107 that a processor with four DA converters), four voltage controlled slew limiters. The basic idea was described
in an internal document of CES (Curtis Electromusic Specialties) and realized in the Oberheim Xpander. In the service manual of the
Xpander the principle of this filter is also described. You can find it in the internet.
As the A-107 was developed in cooperation with the members of this group about 12 years ago you should a lot of information in the
archive (provided that the archives from 2002/2003 ar still available - I don't know).
Best wishes
Dieter Doepfer