Both are possible, depending on what is modulating the engine type:
Damn, that’s wild. Never thought to do that.
I’ve been down on the minifreak for awhile for lots of reasons (mainly the analog filter doesn’t sound good to me and I wish it was a digital multimode filter like the Hydrasynth) and have been wanting to sell it but a combination of laziness and not wanting to eat a lot of the value by selling it on reverb with shipping costs, I’ve come to accept that I’m just gonna keep it.
Been looking at more out of the box ideas for sound design with it and engine modulation is something that never occurred for me to do. Also saw some videos on YouTube of people using the Minifreak as a processing unit which is also something that I haven’t done and definitely adds more value to the synth than what the plugin can do alone (assuming you have external gear to process of course).
It helps when you avoid seeing the minifreak as a “subtractive synth with benefits”.
Try to look at it more like you would look at something like a DX7-style synth with sample-, modelling and granular options, an additional analog filter and built in fx. The above complimented with almost modular-synth-style modulation options, a generative sequencer/arp and a comprehensive user interface to boot!
The magic can be found in many of its parts, other than the analog filter that happens to be there too.
For me the sound shaping on MF is much more in modulating osc-parameters of the digital osc. Also I see the built in FX as part of the sound shaping, especialy since you can modulate the fx-parameters like you can with any other parameter on this synth. On most other synths I would turn fx off when recording, but with my MF they’re an integral part of the patch/sound.
Maybe it helps that I started with a MicroFreak, in which you can accomplish many things with just one of these digital engine-based oscs and in which most modulation parameters were monophonic. The added polyphony, FX, the improved sequencer, modulation macros (morph!) and expanded modulation options make it so much more than a “microfreak x 6 with added multiFX”.
If you limit yourself to using just one of the digital oscs as such, you suddenly have all sorts of interesting digital filter options on the second. The other “processing options” for the second osc are also quite inspiring, especially when modulated!
A bit of a rambling, but maybe it helps you to appreciate your MF for what it is. 
Haha I’m in exactly the same position. I’ve been using it as a midi controller because it’s a slightly bigger and cooler looking keystep.
A cool thing to do as a processing box is that it can be 12 band filterbank. Set the filters to bandpass and keytrack and set the second osc to be another filter and the first osc to external input and you have a filterbank that you can change by playing the keyboard.
Just got a minifreak a week ago and noticed the aftertouch just feels like an on-off switch. Is this normal or did I get sold a lemon?
Setting it to cutoff for example It feels like it doesn’t react unless I press hard enough, then it goes full aftertouch most of the time unless I’m really precise with the pressure, and only if I very careful reduce pressure does the cutoff go down. It’s extremely hard to modulate even with the exponential aftertouch curve.
The filter definitely leaves more to be desired. The bandpass basically sounds useless to me and the lowpass is just too gentle, I can see the benefits of the 12dB slope in making it transparent and it seems to help sounds sit more forward in a mix, but I just wish it had more analog models. If you have a syntakt (and this is a bit of a hacky solution) you can theoretically use the filter on syntakt’s FX track and have midi notes from the minifreak trigger the filter envelope on syntakt. Just have minifreak send midi on the same channel as the FX block (which should be 14). Also don’t forget osc 2 can function as a digital filter and has quite a few slopes to pick from
Works similar here.
I’ve gotten used to the Mini’s aftertouch, but I do think it can be a little tough to use the aftertouch in an expressive way. To me, the linear curve feels like the best one for responsiveness along the key travel.
In case you missed it, there are two other settings in the util menu - AT Start Sensitivity and AT End Sensitivity. You may be able to adjust these from the default to improve it. I don’t remember what the default is but I do remember trying the different settings.
Oh, I did miss those. Thanks! I’ll play around with them and see if it helps.
Also does anyone have an issue with the filter envelope knob snapping to center when trying to set really low filter envelope amounts? I can’t set it anywhere lower than 4 or 5 or else the knob just physically turns into the zero notch. it’s like that only in the positive direction though
Yeah, I think the filter just doesn’t sound like what I’d expect an analog filter to sound like. It’s way more tame in a way where I have digital filters that I prefer (not that there’s much of a difference nowadays with good programming but I think everyone knows what I mean).
But part of it might be that I’m just spoiled with analog filters. I’ve got 5 Moog synths. Used to have a Peak and that filter was incredible (really miss that synth). Have the Syntakt and have bought and sold other analog filters.
They all usually had either a really juicy filter or super smooth (thinking of the Oto Boum). The Minifreaks feels more clinical. Great for taming things but not great for character. And in that regard I just wish it was a digital multimode filter instead. But we have to sacrifice an oscillator to get what are, in my opinion, the best filters on the minifreak.
If Arturia didn’t make such a big deal about the filter I probably wouldn’t care that much but I see people recommended the Minifreak because it’s filter is analog and it’s absolutely not a selling point for the minifreak. Everything that’s digital in the minifreak is what makes it great, the analog part is the weak part.
Any synth brand that prides itself on using a SEM filter without being able to blend between the different parts of its multimode sections is missing the main interest of this filter, I think.