Resonant Low Pass Filter (Request)

[Silver Blues]

[skeletonghost]

Sorry this took so long! I didn't have any dual gang pots on hand. Circuit is verified I think. Extremely harsh filter, getting some really nice doom tones paired up with my bass using a RAT or meathead dark. There seems to be a bit of a dead spot when the controls are both dial-ed in on particular spot, lots of oscillation and the instrument signal cuts. Right before the breakup area getting some really sweet SOMA-esque sounds.

Tried it with my lunetta synth as well and works fantastic! For that I may mod-out the reso pot for a vactrol to add CV control. Come to think of it, this could be the building blocks for a pretty cool wah effect, swap out the reso or cutoff for a vactrol and variable LFO.

[Silver Blues]

Nice!

[amsterdam]

This is a cool sounding filter. I've replaced the cutoff pot with a couple of 2-22k LDRs and used this Super-Simple Dual-Wave LFO. Sounds very cool! A nice leslie-esq filter, sounds similar to the filter side of the Tremshifter.

I replaced the 68k resistor in the LFO with a 100k trim and dialed that in by ear. I'm getting a fair amount of ticking on the square side, but close to none one the triangle side. So I'm sure that's caused by the LED turning on and off. If anyone's got a suggestion to clean up that ticking, that would be awesome. This could make a great addition.

The 10k pot seems like it may be too much (maybe I'm backwards - it was late last night), I was getting a lot of whistling for most of the rotation. I'll try a 1k or 2k pot tomorrow.

Thanks for the layout!

[amsterdam]

It turns out that it was just the LFO that was super noisy. Switched that out with the Madbean Modulaterator and things started running smoother. Some values have to be changed to get the LEDs lighting up, but this project is sounding pretty cool.

[nocentelli]

Do you have a link for the schematic for this?

Silver Blues wrote

Filter.png

EDIT - found it:

http://electro-music.com/forum/phpbb-files/thumbs/t_12db_lep_filter_857.jpg

[glasspak73]

Will this work as a low frequency electronic crossover to run subwoofers for a PA system?I have a set of 18" subs i want to build just a low end frequency crossover to cut all higs and mids out of the audio signal path so my subs only get say 200Hz and lower.just curious if this will work?

[kragg]

Hello
Thank you for the veroboard layout.
I am considering building this filter, but what should i change to make it a HPF ?
Or, better : what should i do to have a LP/HP switch ?

[GrooveChampion]

Yes, I second Kragg's question, is there a way to make it into a hi pass filter as well using the same layout?