#127

Thank you for the clarification. Given that QPAS doesn’t track per se, how far can you get in terms of melodic pinging with the expo input?

1 Like
#128

Hmm, I hadn’t thought about lack of 1V/OCT tracking. That seems unfortunate given how I often want bandpass filters to track parallel to their input frequency (which seems especially relevant with a multi-peak filter that can ring for some time like this one does, and ping so nicely). It’s not a deal-breaker, but a mild disappointment.

#129

I find pinging it so enjoyable that I almost wish I had two QPAS, one for filtering and one for pinging. I get Subotnick-esque sequences even more easily than I do with DPO and Optomix.

9 Likes
#130

@ParanormalPatroler: The 306 looks brilliantly useful and I think it’d be great neighbors with a Cold Mac rather than a replacement.

@ those who tagged me inappropriate: My post was meta-commentary, not a dig. Leaving it unedited for posterity. Don’t know why a “you posted in the wrong neighborhood” joke is inappropriate but I rarely strike that sort of nerve so I’ll trust you guys on this one?

@ QPAS: We want mid-side processed demos!

5 Likes
#131

I can’t wrap my head around this… does this mean the two channels (L+R) are scaled to track frequency/cutoff differently on the FREQ control (so one channel appears to ‘lag’ behind the other)?

#132

It means that the same change in value in the modulating signal has a greater effect at higher frequencies, which is also a good verbal descriptor of the term “exponential”.

The most well-known exponential curve for synthesis is the volt per octave standard for pitch, which mimics the way the human ear hears pitch: in order to be perceived as a change of one octave, the frequency must double, regardless of the frequency range that is being heard. For example a change from 100 to 200Hz (a difference of 100Hz) is perceived as the same amount of change as a change from 1000 to 2000Hz (ten times the difference).

In the case of the QPAS the curve is tailored so that changes in frequency are even apparently “faster” in higher frequency ranges. So if two peaks are far from each other in frequency, a single modulation seems to affect the higher frequency peak more strongly than the lower frequency one. As they approach their highest frequencies this apparent modulation depth closes together somewhat.

The short version of this is simply to say that if these filters tracked 1 volt per octave, it would in fact result in a compromise to the sound of the complex modulation that is possible from simple inputs. The lack of 1v/oct tracking could even be said to be one of the reasons that the QPAS sounds so good.

23 Likes
#133

Thank you for the detailed response, most appreciated!

It sounds like a lot of thought has gone into getting the most movement and interest out of the minimum of controls :+1:

4 Likes
#134

Something tells me this is going to be a lot of fun patching feedback with Cold Mac, given that the crossfader and min/max can be used in stereo, and given you’ll most often have 3 pairs of filter outputs left to pay around with. I’m already planning patches…

6 Likes
#135

Here’s how I’m planning on amending my Shared System to accommodate QPAS. The concept here is that the system would have three distinct voices, each producing its own stereo image, mixed and preserved into a final stereo signal at the output.

  1. Mangrove --> QPAS --> Chronoblob 2
  2. Mangrove --> Erbe-Verb
  3. Sample / System --> Morphagene

Really excited to think about a system I’ve loved for so long in a totally new way.

4 Likes
#136

I gotta say, when I saw the first few demos I wasn’t really interested since the emphasis was on really watery, fast LFO into cutoff kind of sounds - I’m more into really slow sweeps (I post labradford songs every other minute but just like this one here). I’ve never given any thought to stereo filters at all until now actually, it’d be cool to use it to bring slow, subtle animation to drones and noises!

4 Likes
#137

Is it the stereo aspect of this filter that has folks so pumped up? Wouldn’t you get the similiar effect just patching a stereo signal into two filters? I’m listening to these demos and just thinking, that sounds cool I’m going to try patching this up with what I already have in the rack.

1 Like
#138

one of the inspiring things about it, I think, is the ease with which the design allows you to control the unit as a stereo pair while describing what should be different about the stereo images. This is definitely something you can patch up with two filters with careful management of CV, of course, so happy patching :wink:

2 Likes
#139

That’s certainly one aspect (and seems to be a major factor in the design). For me, it’s also a versatile filter with a character that I like a lot, based on what I’ve heard. And to me its design invites more playfulness than most other filters that aren’t Three Sisters :grin:

4 Likes
#141

Was wondering something similar. Hmmm, and I have a Korgasmatron II in my rack…

#142

Ive had my 3 sisters patched as a dual stereo lowpass, or as a 2 peak LP filter ever since i saw the QPAS video. Not yet able to get similar results. Im getting some nice stereo results patching the Instruo Cs-L 2 oscillator wavefolder outs into L/R lowpass of sisters but theres a fairly narrow useful range of modulation of SPAN in this setup before your ear gets pulled in one direction. I think a LRMSMSLR would be useful to keep things centered while modulating the stereo field, but i ended up really liking the character of the QPAS so preordered :slight_smile:

1 Like
#143

I’m very fond of mid-side stereo. I use a plugin in my DAW to do the conversion, but if I didn’t, I’d consider LRMSMSLR a must.

Running the same voice through a VCA and an LPG in mid/side, filtering a little differently, tapping a feedback loop in two different places, running the side signal through tanh[3], etc. is all good stuff :slight_smile: I use headphones a lot both to create and listen to music, so I like having a rich stereo image but dislike unbalanced-sounding panning.

#144

This sounds great.

Would you be able to expand on how you process mono signals in a DAW environment?

Mid Side is something I’ve always been interested in, but getting it setup in DAW’s (and the potential possibilities once setup) has always confused me a little.

Tutorials always seem to be based on eq and compression, but I’m far more interested in getting width/interest from a mono source that covers the whole stereo field.

Mixing / mastering
#145
#146

Sure. I don’t want to go off on too much of a tangent, but what I do is pretty simple (and I plan to try it with QPAS :wink: )

Most of the time I just take my mid and side signals from the modular, assign them as a stereo pair to a channel in the DAW, and put the free MSLR plugin first in the chain. I often have to adjust relative levels of the two inputs to get it balanced, and will add GMonoBass afterward if it seems necessary. (I don’t master for vinyl or mono, but I always want my bass to feel relatively central and narrow in the stereo field anyway.)

If I want to individually process mid or side signals within the DAW, I’ll assign them as mono inputs to separate channels, apply whatever effects I wanted, pan and mix them into a group channel, and put MSLR on the group.

(I use Maschine, which seems wildly inappropriate for the kind of music I make, but I’m used to it and can fly around in it easily. It’s pretty flexible about its audio routing.)

Mixing / mastering
#147

Here is how you can get left right / mid side encoding from your rack if you have a few utilities.

L = M+S
R = M-S
M = (L+R)/2
S = (L-R)/2

edit: maybe we should branch off a topic on Stereo Imaging?

5 Likes
Mixing / mastering