[sdiy] 36dB VCF output drop while increasing emphases

[Chris McDowell]

On the Ripples schematic, the input from J4 is connected to R9 at the input of IC2A, and to C11 at the + input of IC4OTA2, so higher resonance feeds more of the input through. I see now the idea was mentioned earlier in the thread, too. 

Chris

> On Apr 18, 2015, at 1:24 PM, Harald <sdiy at haraldswerk.de> wrote:
> 
> Thanks Ian i think i will order one. And use my 3280 in my other filters as well.
> 
> Am 18.04.2015 um 18:14 schrieb 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?
>>>> 
>> 
>> 
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