INP FA/B inner workings

Elektron Gear Machinedrum
#1

I have been recently experimenting with INP-F machines and got some interesting and weird results by simply throwing at it a GND-SN with a bridge cable from OUT C to IN A, the latter loaded with an INP-FA machine. Even more fun with an FX pedal in between.

I can get pretty interesting things (to me) by tweaking the knobs searching for sweet spots and surprises. but honestly I haven’t managed to completely grasp the idea of the “Input filter follower” as described in the docs.

These are my findings - in random order.

  • ALEV: input gain. At values above 64 the gain boost seems to overdrive the filter rather than increase the overall volume so you can get some nice distortion with it
  • FFRQ: with GATE, envelope parameters and FDPH all at 0 this seems to work as a normal low-pass filter with Q. This alone is pretty interesting to get a filter-bank like setup, as there’s still the other filter in the Effects page (so 3 filters to modulate independently, if you add in the filter of the input machine. Any external FX in between the 2 machines - I use the awesome Moog Drive - can add a lot of extra goodness or evil to it :slight_smile:
  • FDPH: interestingly this is a bipolar control, so depth can be positive or negative. With GATE at 0 and no envelope (FATK, FHLD, FDEC all at 0), the cutoff quickly jumps from (FFRQ + FDPH) to (FFRQ). I would have expected the behaviour to be reversed (jump from FFRQ to FFRQ + FDPH) but maybe my ears are tricking me? Indeed, with low FFRQ (enough to make its effect clear) and a positive FDPH, increasing FATK / FDEC seems consistent to the expectations (frequencies are gradually added in and then taken out). Reversing the equation (negative FDPH and FFRQ open) the behaviour is no longer the same and the envelope does not seem to be triggered the same way. And here I start to get lost.

Further to the above I don’t seem to grasp exactly the relationship with the gate which at low values > 0 seems to make the audio stutter under some circumstances and seems pretty transparent at high values in other cases.

Does any of you have experience with this machine and understand how it works?
I am having a lot of fun with it actually - but, you know, it bugs me a lot not to understand things completely… :slight_smile:

thank you!

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#2

Awesome run down. Never thought of all that. Since i now have a firm modular understanding - its really amazing that the md and mm are so modular like, when you patch in and play around it gets pretty wild.
They are like mini doepfer systems.
I’ll try some of your ideas and report back here. Thank you for the great post.

1 Like
#3

Hi there,

have you been able to figure out how exactly this machine works?

I also have rather hard time wrapping my head around it and don’t really understand how the GATE parameter works.

With the INPUT GATE A/B machine it’s pretty straightforward. GATE parameter at 0 lets everything through. When you increase it, only loud signals are passed through and envelope is applied.

But with INPUT FILTER FOLLOWER A/B the GATE parameter doesn’t seem to work this way. It seems to work quite the opposite to the INPUT GATE machine actually.
It says in the manual - low value lets lower signals through the gate - so high value lets only high signals, right? ok then. I have the GATE parameter at max 127 so in theory only the loudest signals should trigger the envelope (FFRQ at max, FDPH at -64) but in this setting the filter envelope is not triggered, meaning everything is bypassed and doesn’t go through the gate.
Only when I lower the GATE (around 50) the envelope triggers and it triggers only to loud sounds (high signals) and ignores the low signals. So it seems it contradicts the manual - you have to lower the GATE parameter to let only the loud sounds through the envelope and at high GATE the gate will not be triggered. I’m I right with this one?

Can anyone elaborate on this one?

thanks!

#4

What you describe is correct.

The higher the gate, the harder you have to hit it to trigger it. So with your gate high, only the loudest signals will trigger the envelope. As you lower the gate, more signals trigger the envelope. Maybe when it is highest, it just won’t trigger at all…could be of creative use somehow.