[sdiy] Filters

[harrybissell]

Hiya D.U.G. (*inline)

"The D.U.G." wrote:

> Ok.. I could resist to expose my stupidity.
>
> In a VCF.
>
> Does Voltage Controlled just mean that it has a CV input?

Yes...

>
> Does the voltage modulate the cutoff freq.?
>
Yes...

>
> Is the voltage requried?

Yes... but you could get the voltage from a pot, trimpot, or couple
of fixed resistors...

>
> I.E. What if I want to make a guitar fx pedal?

You'll need a design that can run on 9V (typically) or less often +/-9V (two
batteries).
You may find limited range and headroom in a lot of VCF designs at these
supply
voltages...

Also you may NOT really want V/oct response if you are doing an envelope
follower...
it may not siut your picking style at all.  Linear might be a possibility in
most cases...

H^) harry  (with maybe 20hrs of fresh guitar - env follower exp. this holiday
vacation)

>
>
> Peter Grenader wrote:
>
> >One thing to know though - as a true replicate of the original, Ken's the
> >Steiner filter does not have a large oscillation range  - definitely not
> >across the whole spectrum, probably only three or so octaves.
> >
> >But as a filter (which I would assume would be the primary use *of* a
> >filter) -- THIS THING IS SCREAMING!!!!
> >
> >Very rich - can be warm, but wants to be nasty.
> >
> >kinda like Ken, actually.
> >
> >(kidding).
> >
> >- P
> >
> >
> >
> >
> >
> >john mahoney wrote:
> >
> >
> >
> >>----- Original Message -----
> >>From: "David Reichert" <dreichert at sympatico.ca>
> >>
> >>
> >>>Looks pretty good, just wondering though, is the CV set at 1V/oct or is
> >>>it linear?
> >>>
> >>>
> >>>From http://www.cgs.synth.net/modules/cgs35_syntha_vcf.html:
> >>>
> >>>
> >>Notes:
> >>
> >>a.. [snip]
> >>b.. Frequency to CV response is exponential.
> >>
> >>That means V/Oct.
> >>--
> >>john
> >>
> >>
> >>
> >
> >
> >