Clicks when adjusting filter frequencies [CONFIRMED 503]

I have noticed clicks when I was quickly turning filter frequency knobs:

  • for the lowpass filter from the max downwards
  • for the highpass filter from the min upwards

The clicking sound is more pronounced when the resonance is high but even with resonance at zero it is clearly audible.

It sounds to me that the filters are completely off when the frequency is at filter’s extreme (20,000 Hz for the lowpass and 20 Hz for the highpass), and then, when the knob is moved quickly in the opposite direction, the filter is getting engaged right away at the target frequency without any interpolation.

So it’s (the absence of) ramping again?

To reproduce, just load a continuous sound (Adventure Kid SC Waveforms are great for this), hold the pad and move the lowpass filter knob quickly from max down and back multiple times.

I think something’s definitely up with the filter. I remember @katerkeit showing me how his S2400 was skipping sequenced sample midi triggers at high bpm when doing a filter sweep which could be another issue altogether. Maybe that’s what it was what we couldn’t repro?

I had that issue too and also could not reproduce it. Maybe it does have something to do with filter engaging at a certain time, just before the sample is about to be played, I don’t know.

For such bugs, I wish we knew a little bit more about the machine’s internals so we could make better assumptions.

1 Like

Could you upload an audio example? I can’t detect any clicks. If resonance is high, there is a little bit of volume drop when the filter engages, which is to be expected.

Apologies for a delayed response, I was away.

For the video I’ve loaded AKWF_0093 from Adventure Kid SC Waveforms to the Pad 8 and set the pitch to -24 (HiFi engine, 16 bit). I’m holding the pad while adjusting the filter knob. You can hear that there is often a distinct click when the lowpass filter goes from 20 kHz to a lower frequency. When moving the knob in the lower range, there are no such clicks but rather a faint zipper noise at certain frequencies (strangely, this zipper noise is less audible in the record than when I was listening directly through the headphones).

Here’s what a click looks like under the microscope:

I’ve made this record using the USB out to my iPhone. You can also hear some strange clicks at the very beginning of the record. These were not audible through the headphones when I was recording. You may want to check this bug as well.

Here’s the first part of the audio as WAV:

Thanks for the reply. You’re right, there is definitely some artifact when the filter engages, and we’ll look into it.

But I do notice in your video that there are some other more prominent clicks, that seem to appear before you even touch the filter knob. Right at the beginning of the video at around 3s. What’s going on there?

1 Like

That’s exactly the clicks I meant here:

I’ve also had similar clicks when I was recording the video for the looper bug.

It looks to me that these have to do with USB audio.

Do you get the same clicks when recording USB via your main computer/DAW?

I finally managed to do some tests with Logic. No clicks like those when I was recording with an iPhone.

Good to know. In that case, it points to the iPhone, or cable, or camera kit if you’re using one. Seems like the 2400 is doing what it’s supposed to. We’ll look into the filter though.

1 Like