Description
The Alfa AS3350 dual SVF (State Variable Filter) is a clone of the classic CEM3350 chip that was used in the Rhodes Chroma, one of the ultimate polysynths.
The chip allows you to build various multimode filter configurations, including LP/BP and BP/HP.
Download AS3350 Dual SVF datasheet
There’s also some notes on using the chip from ElectroMusic Engineer Magazine from 1982.
brunob –
I just finished this and I’m really happy with how it sounds..State-Variable really has a different vibe to it.
I used the feedthrough circuit described in the Electro-Music Engineer to feed the Cutoff and Q pins, a 47K from pin 16 to pin 1 for the reference current, and the rest from the datasheet.
Btw there might be a typo there as pin 15 is marked “VCF1 Lowpass Output” where it should be “VCF2 Lowpass Output”
Thanks a lot for this 3350!
patrick (verified owner) –
For replace CEM3350 with AS3350 in a Chroma Rhodes you can replaced the R45 / 46 (38.3K) with 30K resistors.