What's your experience with the filters?

I’m trying to find out more about the filters, things like the differences between the ladder filter and multi mode filter, how they respond to different oscillator levels, different resonance settings etc. It would be very interesting to hear your experience with this. And it would be nice if we can avoid a discussion about whether the A4 filters are bad or good, it’s more interesting to find out how we can get the most out of them. This is perhaps not very interesting to all, but I guess some of you are interested in the topic.

Here is what I have found so far with my A4Mk2:

  • The filters behave VERY differently. The most noticeable difference is how the ladder filter reduce the resonance at lower frequencies when doing sweeps while the multi mode filter continues sweeps with full resonance all the way down to the sub frequencies. This can be a good thing but it can also give very boomy bass or boxy (is that a word?) low mids. And it can cause serious distortion if the oscillator levels are not reduced.
  • Generally I find the multi mode filter cleaner but it can also sound annoying with high resonance levels. The ladder filter sounds a bit drier and warmer to me. And even high resonance levels don’t hurt my ears.
  • Higher oscillator levels reduce the dynamics of filter envelopes, even when the overdrive is not used, I guess the signal is somewhat saturated.
    (This is just my subjective experience, I have not measured anything)

Personally, I tend to use the first filter with its distortion and sharp resonance to shape the core sound and add bite. And then use the second filter almost like an EQ, since it has peak, notch, and bandpass.

I absolutely love the A4 filters, but it takes some time and experimentation to get a feel for their sweet spots and how to best use them for various types of sounds.

You can turn off Filter 1 resonance boost in the settings menu for less intense reso. It’s great for acid-type sounds though.


Thank you for your reply and useful information! What filter would you use for classic vintage type sounds such as pads, strings, brass etc? I have made some sounds that I think sounds good but it’s always interesting to hear other peoples experience. Also, I have read in this forum that some people think the synth sounds a bit muddy. I don’t know for sure, but I suspect this is because the oscillator volume is set too loud. The multi mode filter distorts heavily if you use some resonance, even if you only use one oscillator at 100% volume without any overdrive. Actually, I have never used an analog synth where oscillator volume is so critical.

Oscillator level is critical in many synthesizers. Afaik, in any case osc the level will affect how the circuit reacts.

On some synths you can vary the timbre to a great extend by adjusting the osc volume.

On my AK I usually start with osc level around 20-30, especially when both oscs are used.

I generally like the 2nd filter much more. It sounds very Roland-ish imho, lp2 is kinda like the basic Roland-ish low pass filter, lp1 is crazy in a lovely way. High pass filters are very nice, peak filter is great for boosting the low end when you use filter 1.

I usually use filter 2, sometimes I use filter 1 to alter the timbre before the sound hits filter 2 (close cutoff a little - sometimes with envelope modulation - add resonance and/or distortion).
I might even set up performance macros to have control over both filter and their envelopes - very interesting sounds to be found inbetween both filters working hard. :upside_down_face:

Bandpass sounds lovely, bandstop is great for adding movement (lfo modulate the filter) for e.g. pad sounds.

Filter 1 works well for pad sounds for me and it’s also great for kick drums (self resonating filter), but I also got beautiful sounding arps out of filter 1 and don’t forget the feedback osc.


…i love my a4 forever…

in fact, got rid of all my other analog synths, since i learned that it can do ALL what i want from truu analog charme…

it’s the most everything interacts with everything depending on every little detail to be setted up in different ways within the overall signalflow, of all elektron gear…

so much to do wrong to be leaved unimpressed while left so breathlessly overwhelmed, once u do it “right”…

reading here, is kicking in full on, even after years of using it…
leaving me ashamed with that slight feeling, i still did’nt dive sooo deep as u guys…

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Very well said. :elan: :blush:

This is no competition of ‘who dives deeper’, if you’re getting the sounds you want, no need to worry if you could dive deeper.

There’s only so much you can fit in a mix anyway.

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I use bio hemp filters.