switchable highpass filter ideas?

ok i would like to add a switchable OR variable highpass filter to a few channels. there are many places to start and would like a few opinions on topology and why.

a level and cutoff freq adjustment would be called for here.

so my choices are:

active
passive

and of course the many different configs of each.

this is going in a sandstate channel with standard 5532 opamps so sandstate impedences are the norm. not sure what the level is exactly but I have a place between two unity stages that would work well for this.

I am looking for ideas, not handouts please.

:thumb:

W.r.t. switchable, if you want both 12dB/oct & more than 6 freqs then a simple rotary-switch is out.

A nifty does-it-all circuit is here, I just stumbled on it yesterday:

http://yusynth.net/archives/ElectronicDesign/N-Steiner-VCF-1974.pdf
but it'll have trouble handling too large signals. And maybe you don't like the diodes & want to have just a pot or switched resistors. You could change to that of course, and use an opamp if you like i.s.o. the discretes. It does already have your Q-control.

The idea is of course the same, 2Rvar & 2C and an active element.
You might even want to have alook at those UREI-circuits that added a lowpass without an additional active element. Q could be added to those.
There's also one with a slope-switch.
Have for instance a look at pg 2, 3 & 4 of this thread:
http://www.groupdiy.com/index.php?topic=13848&postdays=0&postorder=asc&start=15

And if you want 'electronic tuning' there's quite a lot here;
http://yusynth.net/archives/index.html

Bye,

Peter

yes -12db/oct is good, i would say freqs at 500hz, 300hz. I only need cut.

how about: http://www.eecis.udel.edu/~girish/HWB/circuit/filter/ActiveFilterButterworth4H.html

http://www.eecis.udel.edu/~girish/HWB/circuit/filter/ActiveFilterBessel3H.html

http://www.beis.de/Elektronik/Filter/ActiveHPFilter.html

http://en.wikipedia.org/wiki/Highpass

for ideas?

How about?
http://www.audio-toyshop.co.uk/Tech_Archive/Neve_history_2/Neve_2065/neve_2065.html

[quote author="uk03878"]How about?
http://www.audio-toyshop.co.uk/Tech_Archive/Neve_history_2/Neve_2065/neve_2065.html[/quote]

Nice reading !

Some 2065:
http://www.musicvalve.com/forsale/2065Xfront.jpg

Does anyone know of a schematic ? I understood that site is adding stuff, so it might appear one day.

Bye,

Peter