Overspill?

[jerzy]

What kind of cable do you use ?

So called "audio-video" cable with RCA plugs. I thought that this will be the cheapest and fastest way, but looking inside cable shows that in reality it's not coaxial but symmetrical:

[dmitri]

1. Are your pads fully mechanically isolated from each other and so you can conclude that crosstalk is caused by electrical interference or overvoltage?
2. You can quite easily test if the pad is too hot (signal from a piezo is too strong) for MegaDrum. Set "HighLevelAuto" to Yes and hit the pad as strong as you consider a strongest hit you normally do. Then check what MegaDrum shows in "HighLevel" for this pad. Is it more than ~900-950? If so, and "Gain" for this pad is already set to zero, than the pad is too hot and you're loosing dynamic range. You either need to put a trimpot for this pad or dampen the piezo.

Ad.1: I don't have real pads yet, so I'm connecting just single piezo.
Ad.2: I'll do it, but I have to read sysex description first or try to run MDC with Wine, as I don't have LCD nor Windows. My current tests were carried out on default settings.

MDC doesn't support latest firmwares. At the moment with recent firmwares you can only save/load configs to/from a PC using MIDI-OX.
And of course you'll have to understand MegaDrum SysEx format to deduce any settings/values from it.
Since you're running MegaDrum with default settings I have to say it'll behave far from optimal with your particular pads/piezos.

[jerzy]

Since you're running MegaDrum with default settings I have to say it'll behave far from optimal with your particular pads/piezos.

Test shows that for this piezo highlevel can reach above 1000 (even with gainlevel set to 0Fh), but crosstalk can appear as low as 140. That aside, intuition tells that even with suboptimal configuration settings with just one piezo in the circuit there should be no crosstalk.

[dmitri]

Since you're running MegaDrum with default settings I have to say it'll behave far from optimal with your particular pads/piezos.

Test shows that for this piezo highlevel can reach above 1000 (even with gainlevel set to 0Fh),

Of course you meant gain level was set to 0 not to 0Fh.

but crosstalk can appear as low as 140.

How could you measure this?

That aside, intuition tells that even with suboptimal configuration settings with just one piezo in the circuit there should be no crosstalk.

True, there shouldn't. On how many other channels do you get crosstalk signals?

[jerzy]

Test shows that for this piezo highlevel can reach above 1000 (even with gainlevel set to 0Fh),

Of course you meant gain level was set to 0 not to 0Fh.

Right. I meant, that I was setting next to last byte of particular pad configuration string in sysex dump to 0Fh, which I learned from "menu_layout.pdf" means gainlevel=0.

but crosstalk can appear as low as 140.

How could you measure this?

I have by default this pad configuration string:

Code: Select all

030a 0901 0104 0008 04000000 0104 0002

I'm changing it to:

Code: Select all

030a 0901 0104 0008 00000000 0104 0F02

Now I'm delicately tapping piezo observing Channel Voice Messages. As soon as different key/note number than "3a" appears (reminder: only one piezo in system:-), I'm dumping sysex config and have:

Code: Select all

030a 0901 0104 0008 080b0000 0104 0F02

(008bh=139dec)

That aside, intuition tells that even with suboptimal configuration settings with just one piezo in the circuit there should be no crosstalk.

True, there shouldn't. On how many other channels do you get crosstalk signals?

On most:) I think I have to disconnect multiplexers control bus and check that statically just to be sure it's not 4851.

[elrules]

If you tap the piezo directly with your finger you get a really strong signal. Wait until you have it with a foam cone. It is muuuch better

[denis]

Overspill problem is solved with 74hc4851 ics. I'm using 41mm piezzo disks and my pads are abit hot=) But there no overspill even I tap them with my fingers.

Thanks Synthex

[slayer666]

I'm using 41mm piezzo disks and my pads are abit hot=)

I guess you have set gain to 0 in the megadrum with that huge piezo?
I use 20mm piezos and I have set the gain to 0 to get rid of all noice causing doubletrigging.
Are you experiencing doubletrigging?

[denis]

I'm using 41mm piezzo disks and my pads are abit hot=)

I guess you have set gain to 0 in the megadrum with that huge piezo?
I use 20mm piezos and I have set the gain to 0 to get rid of all noice causing doubletrigging.
Are you experiencing doubletrigging?

With default settings ofcource I have doubletrigging but with if you dial with the retrig,threshold and scan time settings there is no problem. Also I'm using 41mm on my snare and it's 13" on 10" tom and for rims I'm also using 21mm ones.

I wish I could find 35mm ones but they are not common in my country.

[slayer666]

I'm using 41mm piezzo disks and my pads are abit hot=)

I guess you have set gain to 0 in the megadrum with that huge piezo?
I use 20mm piezos and I have set the gain to 0 to get rid of all noice causing doubletrigging.
Are you experiencing doubletrigging?

With default settings ofcource I have doubletrigging but with if you dial with the retrig,threshold and scan time settings there is no problem. Also I'm using 41mm on my snare and it's 13" on 10" tom and for rims I'm also using 21mm ones.

I wish I could find 35mm ones but they are not common in my country.

Which country?