Inconsistent clicks (analog machines)

[JMGSound]

When designing analog kick drum sounds I am getting a click sound that happens at the onset of the sound. The strange thing is that the click varies in level each time I trigger the sound. To me, this sounds like when an OSC is free running and the waveform can start randomly at any point in the OSC phase. This would explain why the click is at different levels for each trigger. However, I have tried using DVCO and set the waveforms to retrigger mode. Also With BD Sharp where you get the option to reset the waveform on each trigger. But I still get the clicks.

The other thing it could be is something to do with the AMP envelope. Maybe there is still some sound leftover in AMP (from the previous trigger) when the envelope is retriggered. I can not use a slower attack to remove the click as this softens to transients too much.

Using the filter with a very low LP frequency does not filter out the click which makes me think that the click is not happening at the OSC level but rather at some point after the filter. So it must be the AMP envelope, right?

Could anybody help me, please?
What is causing this?
Is there a way to improve it?

Thanks

[avantronica]

@JMGSound

DVCO and set the waveforms to retrigger mode

They don’t have phase reset, the R is for ringmod between the oscillators

@JMGSound

With BD Sharp

There’s a click on BD sharp irrespective of any phase thing when the oscillator may be at a different position from one moment to the next

The issue can be alleviated somewhat by disabling Amp Envelope Reset in either AHD or ADSR mode, but that comes with obvious caveats if the envelope profiles are destined to ‘overlap’

It’s the nature of the beast I’m afraid, a slow oscillator will click very obviously if you amplify its signal quickly - especially as there’s likely more going on, even if filtered down post LPF than a pure harmonic starting from scratch

Looking at the waveform and frequency content more analytically might help explain what is happening

Snappy envelopes ! No issue for me as I like clicks, but unless there’s something fundamentally wrong with the intended implementation then it’s just about balancing your needs against the constraints presented

[JMGSound]

DVCO has phase reset. It is depicted by the dot at the start of the wave shape image.

BD Sharp also has it (same thing)

The filter will filter out any signal that goes through it. As the tone of the click does not change in any way (when lowering LP cutoff), then the click must be generated after the filter.

I also like clicks when I intend them to be there but only when they are consistent for each trigger. Having a transient change character for each hit is not good.

Maybe the answer is something about the AMP envelope reset that you mentioned. I am not sure I have a full understanding of this feature yet. Could you please explain it in more detail? What exactly happens in each ADSR stage and when is it relevant?

[avantronica]

@JMGSound

DVCO has phase reset

Yes my bad (eyesight/memory), that’s also a much simpler tone profile filtered that the reset sharp machine i tried it filters out better

The Amp Envelope reset is analogous to the phase reset of an oscillator and it’s there to offer an alternative ‘overlapping’ envelope profile by minimising quick amp level jumps which might introduce clicks if reset to zero abruptly and raised immediately - the envelope profile just deviates from its current position

[LyingDalai]

Try the amp envelope reset with a tiny bit of attack (like 1 or 2) and see if this suits you (+ report please )

[JMGSound]

I’m afraid I do not understand your explanation of the envelope reset function.
If I understand correctly it is only relevant if a new trigger occurs while the previous trigger is still partway through the envelope phase.
If this is the case what exactly happens? Does the envelope completely ignore the new trigger and simply finish its phase? Does hold the current state until the value of the new trigger matches the current state and then continues the phase?

Either way, the feature is not removing the clicks for me, unfortunately.

[JMGSound]

I tested this and unfortunately it does not help. The attack when set greater that about 6 does smooth out the clicks but then this is because it has pretty much smoothened out my entire transient which is not ideal.
Amp envelope reset does not seem to change things.

To try for yourself:
Load BD Sharp. Set Tick to 0, make sure OSC reset is on, set low pass filter to min frequency (with no envelope). Set amp envelope mode to AHD, with attack 0, hold 16, decay 16.
Notice the clicks are different for each trigger? They get softer and then harder right?

Obviously these are not setting I am using to make a kick sound, rather they are to more easily hear the inconsistent behaviour.

[aDc]

I am sorry if this is too off-topic (happy to delete, in case): the clicks really bother me on the Rytm and it seems to me that the Syntakt is almost click-free in comparison. Like the sounds’ attack components are a bit too loud or pronounced in comparison to the body on Rytm.

[Dr.K]

I had a similar thing happen with the tone synth. It would have random clicks in the beginning, no matter how much attack i would dial in. I don’t know if it’s caused by the setting of one of the synth engine parameters or the amp/filter settings. It’s a relatively quiet click but still there and not on every note. I’ll try out some more options to see if i can solve the problem.

[FreddyUnreal]

@Dr.K

tone synth

This person is leaking the SynthTone already! #confirmed
/s

[JMGSound]

OK, so after some more testing I think I have found the issue!
The clicks happen when the decay parameter from the synth page is longer than the length of the amp envelope. It seems that when the amp envelope re-opens there is still a little signal left behind from the previous trigger. I was using the AMP envelope as the ONLY envelope to shape the entire sound, but it seems that I also need to consider the decay in the machine too. It is a little disappointing as the amp envelope shape will now be different as the 2 envelopes combined will create a different shape. It especially impacts the use of the hold stage. I will report this to Elektron as a bug, as NO sound from a previous envelope should be leaking into the next envelope. At least now I know what the issue is and I can learn to navigate around it. Not a massive deal, things still sound great

short version
If anyone else is getting clicks simply reduce the “DEC” parameter on the “SYN” page until the click has gone. Hope this helps.

[7schlaf]

thanks for the hint!

[avantronica]

@JMGSound

I will report this to Elektron as a bug, as NO sound from a previous envelope should be leaking into the next envelope.

Nothing’s leaking anywhere, it’s definitely not a bug, it’s the nature of what you are trying to do without accepting the simple realities as I’ve stated above and I’m pretty sure Elektron will advise that there’s nothing they can do (as that necessitates compromises, at best)

Here’s why it’s generally only ever discussed in the context of low frequency or simple fundamental waves … it’s because it’s just so much more obvious

You are triggering an envelope whilst the oscillator is currently sounding a low frequency wave, that existing wave can be at any position in its phase cycle, so it’s immediately reset to zero, this means a potentially massive change in the existing periodicity at the transition and the typical evidence of this is shown below, with and without oscillator reset for both the ‘saw’ and ‘sin’ - this is a single oscillator from the DVCO, no filter and amp fastest/longest i.e. fully open. Only adopting to use SYN decay to show it doesn’t change the reason clicks occur, it just avoids the issue by taking away the key ingredient, which won’t always be an agreeable compromise, especially for the DVCO or long kicks etc

The issue I was discussing above relating to the envelope profile is no different whether it’s the amp envelope or the internal ‘fade’ settable per oscillator

It’s all about what happens when the phase is arbitrarily reset in an instant, there will almost certainly be a very obvious change in the frequency content due to the truncated wave which is implicitly short relative to the interrupted content … shorter waves are higher frequencies and as it’s always less than a cycle and probably between two lower frequency ‘neighbours’ it is conspicuous too - this is just not as noticeable with higher frequency ‘busy’ content, but it happens there too, you just notice it way less and as the content frequency is higher it can be that the ‘click’ interruption is of a similar frequency anyway

Further, slow AMP envelopes will NOT address this, as you are still going to abruptly cut the existing wave at an arbitrary phase point and therefore truncate a low frequency cycle into a higher frequency cycle

This is why there is a so called ‘analog’ envelope option which does not reset the amp envelope, so the envelope builds from where it is, this can result in less severe interruptions as the volume profile isn’t being as radically transformed and may be less conspicuous irrespective of any oscillator phase reset

I’m discussing this in detail because my points are missed and it helped when doing this for OT transitions when streaming from card or ram at loop points, it’s the same basic physics - you’re interrupting a wave and implicitly truncating it in some way, therefore creating high frequency blips

The reason it is ‘inconsistent’ is because the phase is completely arbitrary when the oscillator is triggered (if not resetting) or retriggered (if not or even if resetting)

This isn’t a bug and the workaround is only making a difference because you kill the source sound, so there’s no wave to ‘interrupt’ - it obviously only works if oscillator reset is enabled, but it’s no use for the DVCO if you want sustaining notes (you don’t want any SYN decay) and it’s no use for notes close together as you still have the same basic fundamentals crashing the party - interrupted low frequency waves are going to click

Here are a few pictures which always help clarify the thoughts

There’s a set for DVCO ‘SAW’ and ‘SIN’ with Phase reset on and off and also where notes follow one another, in this case octave jumps up

There’s a clarification diagram at the end showing how the phase of the wave you interrupt is completely arbitrary and therefore introduces unavoidable clicking, the theoretical mitigations for this are unpalatable and this is why it’s just something (especially on an analog circuit) we just need to accept as the nature of the beast

This is one of those topics that people come back to time and time again, insisting it’s a bug without considering what is actually happening, I hope this post goes a little way to understanding why there is inconsistent clicking and when it’s most noticeable

---

SAW FREE

SAW PHASE RESET

SIN FREE

SIN PHASE RESET

---

PHASE ‘JUMP’ POSITION IS ARBITRARY : Existing waves will generally click

Consider the truncated (dashed triangle) wave-period ahead of the reset phase oscillator with ANY amp profile - you generally create a ‘higher frequency’ perturbation that will be more or less obvious depending on when the new note is requested … the lower the frequency either side of the transition, the more obvious, the interruption impact is arbitrary (thus inconsistent) and largely unavoidable

ANY AMP profile to the right of the trigger point, whether reset or not, will not change the fact that you have ALREADY forced a premature termination of a wave which is implicitly shorter and will be conspicuous in low frequency simple content. This is most evident with content which is tending towards being of a low with simple fundamental only nature, therefore the contrast of this ‘diverted’ wave is simply more obvious than it would be in almost any other circumstance.

A bug is unexpected behaviour, this is not a bug

[JMGSound]

I understand your explanation, thanks for taking the time to explain things (although I must say you seem angry about it, with the bold and caps etc I hope not, maybe I just read it wrong )

At the moment a new envelope is triggered the waveform is suddenly changed from one state to the new (reset) state causing a click. Inconsistent because there is no way to know at what point the wave will be when the envelope is triggered. I understand this. But what I do not understand is this:
When a new envelope is triggered the signal level is momentarily at silence for the length of the attack time until the level is brought up to full volume. Even if the attack time is set as short as possible it does not start at full volume, rather it starts at silence and then as fast as possible rises to full volume. If the amp is silent at the moment the wave is reset, how is the sudden change in wave shape even audible?

For example, if attack time is set to a value of 2 (not sure what this equals in millisecond) then the envelope is definitely starting with silence and then very quickly rising to full level. The time it takes the envelope to fade the level up is after the moment when the wave was cut, so how can it be audible?

Also, I still do not understand how exactly the envelope reset feature works. You referred to it as “so called analog”, where did you get that from? I do not see a mention of this in the user manual, is it referred to this way in a different manual perhaps? If the amp envelope is halfway through the decay stage and a new envelope is triggered (with the AENR turned off) will the new envelope simply ignore the new trigger and finish its decay stage as normal, or does the new envelope jump back to the start of the decay stage again? If you know how it exactly works, please explain it to me (if you don’t mind)

The last thing confusing me here is how is this related to analog only? Surly a digital OSC could also be at any point in its wave cycle when suddenly asked to reset to zero phase and this would cause the exact same clicking behaviour, right?

I tried all my other synths for the same behaviour and I am not able to replicate it.

[avantronica]

@JMGSound

you seem angry about it, with the bold and caps etc I hope not, maybe I just read it wrong

it appears you haven’t quite even read it - the bold/caps is an emphasis (amidst a dense text that is probably quite repetitive, to make the point register), had you read what was emphasised (rather than noted the emphasis) you may not have needed further clarification

it’s explained enough imho to be useful to those curious/interested and as a springboard for further thought … anything that needs extra reflection can surely be googled

it’s already frustrating to have to witness these things recirculate, be it on DN, OT etc and have it discounted as a bug

There’s plenty of food for thought posted here/elsewhere, it’s perhaps an idea to reconsider some assumptions as to why it’s maybe not a bug and just a factor in the nature of the content and that it may involve compromises

There may be mitigating aspects that can be incorporated, but as you can’t predict the future, nor necessarily delay what’s present to the future just to make its arrival/transition more seamless or transparent - it’s the nature of the problem that you can’t have it all, not on a monophonic voice, not without some compromise and mitigating for it is obviously much easier in the digital domain

It’s all relatively easy to try out and that (along with some visualisation perhaps) is the best way to examine it on your own terms - especially if using a sonograph or spectrograph for all the nuances being considered

[avantronica]

[JMGSound]

Of course I read it
Maybe consider making your text less “dense” and “repetitive”
I also did not ask for further clarification on the points you raised, rather asked questions that were not covered in your explanation.

It seems you are exiting the conversation now and are not willing to answer my other questions. OK, thanks for your time anyway

I have to disagree with you about this being the nature of monophonic synths as my other synths do not exhibit this behaviour. This is in fact the nature of Elekton synths.

Newly triggered envelopes should start at the OSC reset point (which is silent) and not include any audio from the previous part of the wave (before or during the reset). It seems to me as though the envelope is triggered slightly before the wave reset. If it were triggered after then no sound from the wave reset could be heard.

I will continue the conversation with Elektron support regarding if this can be improved.

[avantronica]

@JMGSound

Newly triggered envelopes should start at the OSC reset point (which is silent) and not include any audio from the previous part of the wave (before or during the reset). It seems to me as though the envelope is triggered slightly before the wave reset. If it were triggered after then no sound from the wave reset could be heard.

The bold ‘Angry’ bit for context here

@avantronica

ANY AMP profile to the right of the trigger point, whether reset or not, will not change the fact that you have ALREADY forced a premature termination of a wave which is implicitly shorter and will be conspicuous

I’m repeating what needn’t have been repeated had the text been considered rather than dismissed because it doesn’t fit a prior assumption.

[JMGSound]

Yes, I read this. I agree that it doesn’t change the fact that the wave was reset prematurely. But that is not what I am debating.
I am stating that a new envelope and a newly reset wave both starting from silence should not have any audible artifacts from the wave shape being prematurely interrupted.
If the new amp profile was truly starting at exactly the wave reset position then there would not be a click.

[kluzterfuk]

What you’re hearing is not the new envelope and the newly reset wave. The click comes from the previous wave that is abruptly being cut off.
If a wave is not at zero amplitude, it doesn’t matter if you start or stop it in an instant, it will click anyways.