Random Gain sudden changes

[Ilraga]

Hi all
I have a serious issue on my snare, that I’m not able to solve despite months of testing, setting changing and big suffering…
It happens that randomly, while playing, some hits on the snare sounds with higher gain (3-4 steps, I can say) than it is set. This runs for 7-8 hits on the snare, then returns normal, and then again
Gain value on the setting menu does not change, the same all the rest, but the pad is much more sensitive, same as if you have rised the gain value.
This happen randomly: sometimes just as I start play when turning on Megadrum, sometimes never.

I’ve worked hard on the setting many and many times: maybe it seems all OK, without anymore sudden changes, so I save all setting, including the ones of the pad, but maybe on the next session with the same setting, the same problem returns...
My pad is DIY with a Jobeky center trigger, previously I used a DIY alluminium disc trigger, that have the same behavior problem. Also tried with a new cable: same problem.

I've tried all setting changes and combination, without success.
It seems that lowering down gain value and minscan value reduces the frequency of the problem, but not solve it, below my setting

Any suggestion?

IMG_20251022_210545114_HDR1.jpg

[dmitri]

A few possible causes:
1. There is a bad soldering on one of the voltage dividing resistors. If it is a snare then it would be R26 and/or R41.
2. There is a short on one of the voltage dividing resistors. If is a snare then it would be R16.
3. If there is a voltage dividing resistors in the snare then there might be bad contact(s) on the these resisitors.
4. There some noticeable voltage jumps/drops on the usb port to which MegaDrum is connected to.

[Ilraga]

A few possible causes:
1. There is a bad soldering on one of the voltage dividing resistors. If it is a snare then it would be R26 and/or R41.
2. There is a short on one of the voltage dividing resistors. If is a snare then it would be R16.
3. If there is a voltage dividing resistors in the snare then there might be bad contact(s) on the these resisitors.
4. There some noticeable voltage jumps/drops on the usb port to which MegaDrum is connected to.

Many thanks Dmitri!
First attempt was on the easiest causes: cleaned the usb port where MegaDrum is connected to, and sobstitute the usb cable, but no success... I'll move on to check on the soldering and short issues you suggest, but this will need more time. I'll be back asap

[Ilraga]

A few possible causes:
1. There is a bad soldering on one of the voltage dividing resistors. If it is a snare then it would be R26 and/or R41.
2. There is a short on one of the voltage dividing resistors. If is a snare then it would be R16.
3. If there is a voltage dividing resistors in the snare then there might be bad contact(s) on the these resisitors.
4. There some noticeable voltage jumps/drops on the usb port to which MegaDrum is connected to.

Hi Dmitri
A friend of mine tested all the point you indicated with a Multimeter, but all soldering are OK...
Meanwhile we repassed the soldering on the snare input jack
No resistor are in the snare input or pad

So I moved all the device to a dedicated stand-alone drum stand (previously it was mounted on the drum rack) to eliminate any possible effects due to vibration and worked on the configuration, again.
I can say that the problem is now reduced (in frequency and duration) but is still there, and I really do not have idea how to solve this...

Any other idea?

[dmitri]

The only two other things I can think of:

1. MinScan is too low for the signal from the snare to cover full signal consistently. The bigger a mesh snare the higher you have to set MinScan. Set MinScan higher.
2. Some mechanical/electrical problem with the cable(s) or jack you use for this snare. Try other cables.

[Ilraga]

The only two other things I can think of:

1. MinScan is too low for the signal from the snare to cover full signal consistently. The bigger a mesh snare the higher you have to set MinScan. Set MinScan higher.
2. Some mechanical/electrical problem with the cable(s) or jack you use for this snare. Try other cables.

New cable pad/MD, same problem...
I'm quite sure the problem depend on the configuration of three paramater: Minscan, Retrigger, and Positional (Pos Low and Pos High). Not clear why, but with the following setting, the problem is reduced

Immagine.png

[dmitri]

Did you try the same pad in other inputs?

[Ilraga]

Did you try the same pad in other inputs?

Yes, but... same problem
I switched snare on Aux6, but after few minutes, same random gain changes.
This also show me another problem: the same setting of the same snare pad result of completely different performance when the pad is connected to snare input or in A6 input, and I don't understand why...

[dmitri]

If your MegaDrum has the built-in Positional sensing addon then 5 inputs - inputs 4, 6, 8, 10 and 12 - will have different signal voltage and will need different Gain/Threshold/HighLevel settings from all other inputs for the same pad/cymbal.

[Ilraga]

If your MegaDrum has the built-in Positional sensing addon then 5 inputs - inputs 4, 6, 8, 10 and 12 - will have different signal voltage and will need different Gain/Threshold/HighLevel settings from all other inputs for the same pad/cymbal.

Please Dmitri help me, I'm desperate... I'm quit sure my Mega Drum module have some bug

Today I spent all day working on that issue
Following your suggestion, I've switched the snare to Input 8 (originally Crash 1): here the snare setting was OK
I played a lot without any more "gain sudden shanges" problem: eureka!
I tweaked a lot the snare (head) setting so to find a better performance. I finally defined the setting you can see here below, that sound GREAT: great dinamics, perfect flams, doubles, triples gost notes, positional - my snare have never played (and sounded) that good.
Saved the snare config file on my PC (with a new name), saved all to slot 1
I played three (3) hours with that configuration whitout a single issue of "gain changing", just a great snare: eureka again!

When it was almost time to go home, I thought that it would be a good idea to tweak a little also the rim/edge setting, so to improve sensibility and dinamics of the rim: so I moved a little the gain and high level (rim/edge) when suddenly... my head "gain" rised 3-4 steps resulting now unplayable.
So I run to load the configuration that was praviously saved (that sounded so good for three hours), but nothing: the gain is terrible, too high: you can see also in the graphics here below: note that I was playing very soft...

Immagine.png

Turn off MD, turn on, reload the snare saved fantastic configuration, but no, now all is wrong: it seams that for the three hours before MD applied some "compression" to the gain value, that needed that configuration, then this disappear, so normally this gain is out of control
Please note that ONLY the snare have this behavior: all the rest of the drums play the same way, before and after.

Is my MD broken?