www.megadrum.info

(Not sure if this goes in the hardware or software forum...)

I recently received my MegaDrum module, and it's a thing of beauty

However I'm having huge issues with the sensitivity for all my mesh pads (standard Roland mesh pads with the single off-center piezo for the head, PDX-8 and 6). No matter what settings I use, the signal maxes out when playing at normal - or even low - intensity. Just playing a careful 4/4 beat has the snare registering 127 velocity on almost every hit even after carefully setting the gain and high level.

The cymbals and kick work alright, and stuff like rolls, crosstalk and retriggers are working fine on all pads. It's only the lack of headroom that's causing issues.

If I try setting gain to (for example) 4 and high level to 1023 to make sure that it's not a bad high level setting that's clipping the velocity, the snare hits become a solid row of equal-velocity hits too, so it's not that my regular gain/high level settings are causing the input to be cut off.

My Roland TD-4 module handled the velocity just fine, so I know that the pads should have a better dynamic range than this. If I set that module to be less sensitive I could pound the living daylights out of the pads before they maxed out.

Am I missing some setting here? Can there be hardware issues like the cables used to connect the pads being wrong (whatever that might be, I'm using standard stereo to stereo quarter inch plugs)?

What level are you getting with the high level auto?

Gain 0: 250 auto high level
Gain 8: 1007 auto high level

It doesn't really matter though, because a hit that would register as maybe a 50 velocity hit on my old TD4 would be a 127 on the MegaDrum even when the high level is correctly adjusted. It overshoots and clips at less than half the range of the other module.

It's like the dynamic range of the piezo's signal that reaches the MegaDrum is too large so that it clips before it's even converted to the 127-value range. If that's the case then it's really unfortunate since I guess that means I'd have to open it up and solder resistors and stuff into it (I'm terrible at electronics so I'm just guessing here) which was something I was aiming to avoid by buying one of the ready built modules.

What velocity curve are you using?

Any; it doesn't matter as the regular-strength hits all translate to the top value of the curve anyway.

Curves like the exponential ones can reduce the velocity of very careful hits that register below 127, but the top value is unchanged unless you cut off the dynamic range which I obviously don't want to do.

Ok, set gain to 4 and do the high level thing. From your figures so far I'm guessing around 700 as a high level. So you're saying that this translates to most hits being at 127? And just to be clear, that this is what MD is outputting (as shown in the midi log) not just what you are hearing from your VST?

Gain 0: 235
Gain 1: 246
Gain 2: 256
Gain 3: 274
Gain 4: 302
Gain 5: 371
Gain 6: 486
Gain 7: 703
Gain 8: 1007

It seems exponential pretty much.

And yes it generates 127 for regular-strength hits no matter what gain I use and after I've set the high level correctly. Careful little hits work fine and register as they should but when I increase the intensity of the hits they max out at 127 way before I'm actually hitting the pad very hard at all.

I have two of each mesh pad (PDX-8 and PDX-6) and they all behave the same, so I don't think there's anything broken in any of the pads either (and they work fine in my old module).

I'm not using a VST as the module isn't configured properly yet, there's not much point in trying to actually play the drums at the moment since it sounds like I'm murdering the drums when playing jazz.

Leave the gain at 4 and raise the high level to 800, does that make any difference?

No, the only difference that makes is to set the high level wrong so that the max velocity is ~50 instead of 127.

I appreciate the help with troubleshooting but I feel like I've already gone through these basic steps of gain and high level adjustments, it seems that there's some bigger issue like the analogue signal from the pad itself getting clipped as it "enters" the MegaDrum module. Unless there's some button or setting I've missed, it looks like the module isn't handling the amplitude from the pad like it should, so that it cuts off and compresses the dynamic range of the actual incoming signals.

I'm not a sound or electronics engineer so I might be using the wrong terms, but I hope you know what I mean; like if the pad is sending a signal of -10dB and the module can't handle more than -30dB, that would make the hit interpreted as maxed out due to a lack of dynamic range in the interpretation of the incoming signal even though there was plenty of range left in theory (I'm just using imaginary numbers and units here, not sure how the MegaDrum works internally).

I'm attaching a screenshot of what the pad is outputting when plugged in to my sound card. The first couple of hits are what I'd call "mid range" hits of maybe 50-70 velocity normally, and the last few hits are all out hits that should be ~127 velocity. MegaDrum would output all these hits as 127 velocity no matter what gain or high level I'm trying out, despite there being a very obvious difference in output from the pad.

Please post a screenshot of settings with Gain set to 0 and HighLevel set to 250 and Curve set to LinearCustom1.
Take screenshot of MIDI Log/Visual MIDI after:
1. a few very light hits.
2. a few medium hits.
3. a few strong hits.
4. a few free bouncing stick

Also, can you make a cable with a 10k-30k resistor inline on the tip wire?