Most simple VCF on earth!

[StephenGiles]

http://electro-music.com/forum/viewtopic.php?t=45231

[Mark Hammer]

It's a bandpass, right?  Not that this is a terrible thing.  Just wanted to disabuse anyone of the notion that it was somehow tantamount to a Minimoog filter or some such nonsense.

[Seljer]

Theres a similiar thing in the tim escobedo circuit snippets: http://www.jiggawoo.eclipse.co.uk/guitarhq/Circuitsnippets/simplevcf.gif

[frequencycentral]

You call that simple?? THIS is simple:



From this thread: http://www.electro-music.com/forum/post-188826.html

[R.G.]

I think that LED will be very unhappy when the control voltage exceeds the LED conduction voltage.

A control current would make it a lot happier.

[DavenPaget]

I think that LED will be very unhappy when the control voltage exceeds the LED conduction voltage.

A control current would make it a lot happier.

It will probably bitch about 

[Taylor]

Tim's version, as I recall, actually faked a somewhat LPF-ish response in addition to the big resonance peak. It's a pretty darn good approximation of a synth-style filter for guitar-type apps, considering how basic and cheap it is. One problem is that it overdrives easily due to the diode being used to get the voltage control (I wonder if RG's term "voltage herded" is more apt here).

I used this type of filter in my "fake phaser" which I posted here a while back.