@seed funny, I actually am using [bob~] as well in the project; the main synth voices run through moog~ but I also wanted the patch to work as a guitar multi effect, which I run through [bob~] as a separate filter. I'm about to just give up and do that...

I'm now using PD Extended so I can hear moog~ while debugging (woo hoo!), and I can get the LFO to work but at extended ranges (or if I move the main cutoff values around to the edges) it does this awful glitch/crash noise, I think because somehow the range is out of sync (like, if the main filter is on 600hz, and my sweep is 1000hz, it goes into negative range and sound bad), but this isn't an issue with vcf~. Again, probably something easy i'm missing.

EDIT: I fixed this using a modified version of this code, if anyone has a similar issue:
https://guitarextended.wordpress.com/2012/01/07/wha-wha-auto-with-pure-data/

Thank you for the reply. My (limited) understanding is that the Organelle runs Vanilla, but you can use extended objects if you have the compiled DLL to push to it - this works, as plenty of Organelle patches use moog~ - but when you debug on your computer it doesn't recognize it. Maybe if I install Extended it would work? Anyway, thank you for the filter links, I will definitely check those out .

Still wondering if there is a way to plug in the LFO modulation like you can with vcf~ example from the link I posted... seems like I'm probably just missing an object/conversion/glue that would make it work

EDIT: 2 ways I tried, neither work correctly.

Hello - first post here, fairly new PD user , working on a custom patch for the Organelle, a hardware synthesizer that runs PD inside.

Anyway, I have everything working except an LFO to sweep the moog~ filter object's cutoff. I have researched PD tutorials showing how to sweep a vcf~ object and this works fine, but it takes a number for the cutoff inlet while moog~ takes a signal. I've tried a few things converting and such but nothing that has sounded right. I know I need to get the numbers (with modulation from LFO) converted to signal before it hits the moog~ cutoff inlet. This is hard to test because its a Linux object, I'm on PC, so I can't hear any output until I try the patch on the Organelle itself.
Screenshot:

As shown, the LFO is obviously disconnected....I need to get that modulation 'added' to the cutoff freq before it hits the signal, but also not be out of range , if that makes sense....for example, I thnk the vcf~ filter has a range of 10k for its cutoff input, but moog~ is like 2100 or so. When I had this partially working, high settings of the LFODepth were causing gltiches/noise/silence.

Here is a link to what I'm basing this on (see bottom example)
http://archive.flossmanuals.net/pure-data/audio-tutorials/filters
Thanks