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Post by young Protoboard on Feb 17, 2020 0:16:40 GMT
I'd like to review the behavior of my DRUMKIT 010...
Firstly, a large handful of sounds (at least one per channel) emit a piercing, screaming, high-frequency tone, especially when Pitch knob is turned fully left. It's so head-splitting and painful that I've stopped using it entirely; it's not loud, but it's loud enough to hurt and be disruptive in my music. This behavior is also found in other combinations of Pitch and Bank, on I think every channel.
Does anyone else experience this? It may just be my particular audio setup(s) (or in my rack itself) forming some resonance pathways, but it doesn't really vary significantly with input frequency, so I can't say for sure. I've also experienced it at different setups when traveling with my kit.
This painful noise is in addition to the unavoidable noise of similar character (but lower volume and pitch than the "intermittent" signals) that comes from plugging a bare (no inputs attached) DRUMKIT out to my MIXER 4-4.
Secondly, I would like to confirm that my Bank knob is actually accessing every sound sample. My test patch for this is TOPOGRAF TRIG 1 -> each DRUMKIT channel, one by one -> DRUMKIT OUT -> MIXER 4-4 A1 channel -> I/O port 2 -> to Fostex recorder and speakers.
No other synth lines are patched.
Here are the results of that test patch.
Format:
LINE: # of samples played from rotating Bank from fully-left to fully-right; knob positions of samples (knob range, in percent, from left to right).
BD: 1 sample, full knob rotation.
SD: 3 unique samples; Sample A (0-40), B (40-65), C (60-75), B (75-100).
CP: 3 unique samples; Sample D (0-25), E (25-50), F (50-57), D (57-70), E (70-100).
CH: 2 unique samples; Sample G (0-30), H (30-42), G (42-53), H (53-75), G (75-100).
OH: 4 unique samples; Sample I (0-51), J (51-62), K (62-72), L (72-82), K (82-100).
FX: zero unique samples (all sound identical to previous samples but the whining from the module is hurting me and I can't listen anymore); all spread out accessibly but heavily front-loaded.
Out of every test sample, F was the only one that did not produce heavy ringing at any Pitch position. Most samples produced ringing with Pitch below 40% and in at least one other section of Pitch domain; those wild spots especially kill tweakability in the patch, as I will 1. always hit a screaming section if I try to sweep any parameters with >1 channel used, and 2. not be able to find any combination of inputs and parameters that makes no noise, with >2 channels used.
Has anyone observed similar behavior from DRUMKIT 010?
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Post by robertlanger on Feb 17, 2020 10:08:43 GMT
The high pitch is most likely the carrier frequency of the PWM output. I remember it was audible sometimes with the first batch of DRUMKIT modules where the output filter was too "weak"; can you tell me the version number of the PCB (bottom right corner)? The new batch should be optimized regarding this.
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Post by young Protoboard on Feb 18, 2020 7:49:08 GMT
Listed on the bottom-right corner of the front side of the PCB is DRUMS 010 v1.1. Is the output filter altered/corrected by a component swap? I've never desoldered/soldered SMD components before but this would be a good excuse to try.
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Post by robertlanger on Feb 19, 2020 11:03:12 GMT
This is the current version... Hmm... Seems like the lowpass filter in my old ears doesn't go fully clockwise any more ;-) so I didn't recognize this problem.
You can solder a capacitor in parallel to an existing one to reduce the cutoff frequency of the output lowpass; I will look which one / value and let you know!
At the moment I'm on holidays so I have not immediate access to all schematics but I can manage it, this evening you should receive it.
Thanks and all the best
Robert
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Post by young Protoboard on Feb 19, 2020 18:02:49 GMT
Thank you very much! The support and care you give your customers makes me very pleased to be a part of the AEM community. I hope you enjoy your vacation; please don't rush home just for me!  |
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Post by robertlanger on Feb 25, 2020 10:54:08 GMT
I'm back from holidays; so let's check / fix this issue now! May I ask you for a favor: Can you make a photo of the entire DRUMKIT board? The version number MIGHT BE not fully meaningful. Then I can give advise what to to exactly.
Thanks a lot!
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Post by young Protoboard on Feb 26, 2020 6:26:09 GMT
Here are both sides, in, I hope, enough detail:   I hope you enjoyed your holiday! |
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Post by young Protoboard on Mar 19, 2020 16:05:53 GMT
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Post by woestijnmeeuw on Sept 9, 2020 22:18:26 GMT
Is there any news on this topic, because I experience the same problems...
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Post by young Protoboard on Sept 10, 2020 16:00:08 GMT
Is there any news on this topic, because I experience the same problems... None as far as I know. If I find the time, I should make a recording-- it's certainly not in the "too high to hear" range, unless the last octave or so of every AEM oscillator is also in that range for an individual. |
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Post by tarcreeper on Oct 26, 2020 22:03:06 GMT
I experienced this same issue. It’s fine if you’re just setting it in one position and not touching any knobs or modulating the pitch but that’s a bummer because sending random rhythmic cv to the pitch sounds awesome. It’s technically doable if you run it through a filter but that unfortunately makes it sound even more lofi than it already does naturally.
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Post by arti on Oct 27, 2020 1:22:11 GMT
Same here with the often present high-pitch piercing sound dominating over any other drum sample emited from the module. I try to turn the knobs (pitch/bank) untill it stops. Usualy helps, but turning the knob again make it appear. It also usualy appears with pitch cv input fed by anything.
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cpruby
Junior Member
Posts: 73
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Post by cpruby on Oct 28, 2020 19:40:30 GMT
Mine also emits a super high frequency that peaks my VU meter when nothing is played. It's around 15 kHz and running it through any filter (even my MS-20 in high pass mode) will get rid of it.
This is in addition to it squealing when changing pitch via knob or CV. I'm trying to remember if running it through a filter will eliminate this issue as well.
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Post by Kyaa on Oct 12, 2021 20:35:50 GMT
Wanted to bump this, as I also have the same issue. Did anyone ever come up with an appropriate fix? I'm fine soldering on my board, but it'd be helpful to know which cap I'd have to modify and to roughly what value I'd have to change it to. robertlanger |
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Post by chillja on Nov 24, 2021 20:13:13 GMT
Same here. Would love an in-module solution. i'm not comfortable soldering yet, but would be nice to know what can be done. Tried to get a visual on this issue. - Bass drum only, the lowest of the high frequencies i found: - Bassdrum only, highest freq i found (was stronger in other images): 
- High hat only w/ manual pitch knob: The low frequency rumbling when pitchshifting im ok with, i think i can hear it on NightMaschines youtube video, and its part of it's "lo-fi" after all. Will try out different external filtering solutions in the meantime.
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Post by chillja on Nov 26, 2021 12:58:51 GMT
Edit: Since i like solutions more than problems, im trying to think of ways this might be some kind of feature. Hi-passing out the signal and clock dividing it down? Or boosting it for a new cv source? Wet only with one of the multifx? Seems to be some cool information there when modulating the pitch, just need to bring it down to human listening ranges or boost it for a useful cv signal maybe.
(Tried to edit last post but was just loading on "save changes")
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Post by solipsistnation on Dec 23, 2021 17:30:48 GMT
This is about 50% the noise from the drumkit module through some other stuff. 8)
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Post by tIB on Feb 18, 2022 12:02:38 GMT
Mine seems to have developed a load of digital noise alongside it working as normally should - ie I get the drum sounds but a high level of digital artifacts, not entirely unlike my algodrones, in the background. Any ideas?
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Post by ayuptom on Feb 20, 2022 16:23:39 GMT
I also have this issue. I've routed it through a low pass filter for now but it's not fine enough to control and I'm loosing quite a lot of the freq, reducing the quality of the sound (and the loudness)...
I'd happily add another capacitor if I knew what value and where to place it.
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Post by tIB on Feb 21, 2022 14:44:29 GMT
Yeah, don't mind getting the iron out here either.
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Post by ayuptom on Feb 23, 2022 11:45:54 GMT
I really think it's great that Robert contributes to these discussions, I can see he responded just recently to somebody about their clock divider - it makes this community feel extremely special.
I feel that this topic has gone very stale though and I'm sure that many people with the drumkit module (which must be massively popular) are experiencing the same issues. - here's a bit more info about my specific situation.
I'm getting the high frequency all the time, not just when I change a parameter (eg. pitch) - I have turned it off and back on again, no inputs at all and I'm reading the frequency out of the output still. I took some data from it:
on the oscillator (readout in attachment) the voltage is 0-5v
frequency is (assume 65us time per oscillation) : 1/0.00065 = 15,385Hz
(-18dB on my tascam)
Smoothing it out on the SVFilter with Drumkit out into filter LP in requires a significant cutoff - about 1 o'clock setting on cutoff (CV and resonance fully anticlockwise). It means I cut out all the nice harmonics of the openhats etc which is what I really need to have. I also lose my filter to the drumkit which I really need for other things. with this setting I'm reading -40dB on my tascam.
With Filter applied and with no load from drumkit (ie nothing playing), there is just short of +4v of out of the SVFilter LP output. (see image below, notice my baseline is at the bottom of the screen so it's not reading 0, it's reading just under 4v).
I only bought this unit (from Juno in UK) a month ago but it's well past the 14 days return period. I really wanted a drumkit in the AEModular but this one feels unusable in the current form. I'd happily mod it if I were told how to, I'd even upload new firmware if it were possible. but as it stands I'm worried it was a dud, that there's no drum alternative and that it's possibly going to damage other modules (is that even possible).
I'm happy to do further tests or whatever would help robertlanger, please could you let us know if there's a fix or at least if that it isn't fixable so I can go and find an alternative instead. (after 2 years of no movement on the topic I'm assuming it's the latter). |
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Post by tIB on Apr 4, 2022 19:22:37 GMT
Please can we have some info about this?
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Post by ayuptom on May 20, 2022 14:53:57 GMT
robertlanger admin - is there anything we can do about this. It's a massive pain. either the modules we have are defective and we were unlucky or _all_ these modules are defective in which case are they still to be sold?
would really like to be able to use this module but at the moment it's become unusable all the time as the noise isn't filterable, and it dampens any other frequencies/harmonics from other modules it's mixed with (on any mixer, internal or external). stuck without a drum but even worse when there's no real tech support for it either  ... please can you help us? |
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blake
New Member
Posts: 17
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Post by blake on May 20, 2022 17:48:36 GMT
Mine has the same issue and would also be interested in a solution.
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Post by robertlanger on May 21, 2022 11:46:16 GMT
Hello guys! First, my sincere apologies for the nasty issue with the DRUMKIT010 and even more for the long period of silence from my side.  I almost can't believe it is two years ago this thread has started! For some reasons I lost this problem out of sight *shame* Ok, now let's go for fixing the issue; two different ways: 1 - The DIY way:The output filter, that blocks the PWM carrier frequency (this is what you hear) can be modified by adding a capacitor of 1nF across R23, at the top left side of the board, see here:  The value of the capacitor can be changed; choosing a larger one (e.g. 2.2nF) makes the filtering stronger (at the cost of loosing more higher freuqency components), a smaller one (e.g. 470pF) leaves more of the highs intact, but with less filtering of the nasty carrier frequency. If there are already manual modifications made on your module, please PM me so we can check it in detail. 2 - The tangible waves support way:If soldering is not yours, you can send us the module of course for fixing the issue without cost, no matter when it was purchased. Some more background info:- The (annoying) carrier frequency changes with the settings of the pitch knob from 15kHz to 30kHz, and this four times over the turning range of the pitch knob. So you have a much higher "noise pitch" e.g. a bit left of the middle position and here, the PWM carier frequency should be out of the hearing range - maybe worth a try!
- Soon after this issue came up, I was planning an updated version of the DRUMKIT010 module, with a real digital-to-analog converter avoiding the PWM noise; unfortunately, the last period of time brought some unpleasant surprises, consuming a lot of time to deal with, therefore I lost this issue out of sight, honestly. But the updated DRUMKIT is still on my list and I hope I can get it done in the second half of this year.
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... please can you help us?
I almost can't believe it is two years ago this thread has started! For some reasons I lost this problem out of sight *shame*