Moog Music Forum

I recently got a Matriarch and tried recreating the Dirty Duo patch from the exploration patchbook that comes with it.

(Image source: https://api.moogmusic.com/sites/default ... chbook.pdf)

This patch involves just one cable: patching VFC 1 Out to Noise In on the mixer. I presume this is supposed to create some kind of feedback loop, especially since the patch book sais it 'drives the mixer' and not to raise the level beyond 3 o'clock.

However, raising the noise knob simply does nothing in my case. (Turning the Noise knob it up beyond 3 o'clock seems to introduce a subtle highpass-filter-like effect.)

I've double-checked all knob positions and I'm running the latest firmware. I've also tried calibrating the oscillators and knobs and resetting the global parameters, but nothings seems to help.

Has anyone else had problems with this?

I expected more as well since this is supposedly a very popular old Moog trick. To me it sounds like it increases resonance of the filter, but only really once the signal is driven past 9oclock on the mixer, and even then it's not very impressive.

I also tried running the eurorack out on the back into that noise input, which doesn't seem to make any difference.

I have not tried the patch. (Sorry, I have another nice patch setup at the moment.)

Have you tried using one of the other mixer inputs, in place of the noise input? I wonder if the patch was transcribed accurately. A subtle fact about the mixer is that the noise input inverts the signal. Thus feedback into noise will be negative feedback, which might be stable and undramatic. Possibly, the other inputs will have more interesting results.

Yeah, I tried both using another input and inverting the signal with one of the attenuverters before running it into the noise input.
Still no effect

I have tried the patch, and I can hear a difference between Noise input at 0 or 3pm. But it's a very subtle difference, and I can hear it only when playing a melody (i.e. Filter-envelope being triggered) and not on an individual note.
So a very subtle effect, but a nice one.

I haven't tried it yet (my matriarch is also in a patch i'm currently recording) but I saw a video last night of VCF1 out -> Cutoff1 in and VCF2 out -> Cutoff2 in, which results in something that sounds like feedback, but I guess it's not the same thing?

hudri wrote: ↑Wed Feb 15, 2023 7:36 am I have tried the patch, and I can hear a difference between Noise input at 0 or 3pm. But it's a very subtle difference, and I can hear it only when playing a melody (i.e. Filter-envelope being triggered) and not on an individual note.
So a very subtle effect, but a nice one.

I tried the feedback connection too (with my own patch) and also find the effect to be pretty subtle and limited to very high values of the noise mix knob. Not really that useful. This makes sense, because basically, this is what a Moog filter does internally when you increase the resonance/emphasis knob. It is also usually the case that the filter res knob is a reverse-audio taper, for the reason that this connection has less sensitivity to low amounts than to high amounts.

The more famous “MiniMoog” feedback connection has more character. I believe this is at least partly due to the feedback coming after amplitude shaping by the VCA, making the feedback variable with the output amplitude. Thus, the resonance effect of the filter is changed during the the course of a note’s shape, which is a different effect from static resonance.

Yeah, I just got a Grandmother and the effect is way more pronounced on it than the Matriarch.

Inverting the signal should make the effect much more pronounced. Set an Attenuator fully anti clockwise then patch VCF1 Out -> Attenuator Input and Attenuator Output -> Noise In. I know you said you tried an inverted signal already, but humour me