[sdiy] 36dB VCF output drop while increasing emphases

[Ian Fritz]

The topology of the filter and its nonlinearities are what gives it its 
wide range of capabilities. The operation seems quite sensitive to OTA 
non-idealities (eg, offsets) which is why I recomment the CA3280.  I think 
it could work quite well if the 13700 were used, but probably the very low 
end (in self-oscillation) would suffer.

Ian

At 03:32 PM 4/17/2015, Harald wrote:
>Well it uses 3280 OTAs. I still have some around but never used them. 
>Might be time to change this. Anything else special in this filter? Or 
>does the 3280 make the sound quality alone?
>
>Am 17.04.2015 um 21:56 schrieb Ian Fritz:
>>I'm partial to 3d order, musically.  My 3d order filter has four
>>switchable combinations of HP/LP stages and output from each stage.
>>Demos may be heard/seen here:
>>http://home.comcast.net/~ijfritz/MiscProj/Threeler.htm
>>http://bridechamber.com/Threeler_PCB.html
>>https://www.youtube.com/channel/UC8mKuBoR8bfHTLYRJ1sl0RA
>>
>>Several people have said this is the all-time best-ever filter. I don't
>>know about that -- I've always been more interested in the waveshaping
>>approach to timbre -- but please listen and see what you think about the
>>musicality.
>>
>>Ian
>>
>>
>>At 06:08 AM 4/17/2015, Harald wrote:
>>
>>>Second thought: The filter works quite good. Does it make sense to go
>>>for 48dB musicaly?
>>