Make Your Own Drum Pad!

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/ theaudiophool
A nice easy one this week, we're going to make a drum pad out of some bits and pieces i have kicking around, and we're using an op-amp comparator circuit to turn the drum pad output into a trigger. This can then be used to do whatever you want! We explore a simple envelope generator as a method of controlling a few drum sounds from previous videos.
conductive foam: www.amazon.co.uk/gp/product/B...
Schematics:
Single Supply: drive.google.com/file/d/1H4uP...
Split Supply: drive.google.com/file/d/10sUn...

[@the_electronicTech]

This guy does serious electronics

[@jjfeeney9769]

Dude this is awsome just took an intro to circuits course and wanted to make a kick drum pedal for when I’m playing guitar and your videos are super awsome!!!!!

[@euglossine4ever]

You the best, thanks professor

[@yurkshirelad]

Brilliant!

[@almanaotemolho]

excellent content

[@AhmetKizilay0]

Great video!

[@zetaconvex1987]

Oh wow. I'm interested in making a drumpad.

[@bsatyam]

Awesome as hell!

[@twobob]

quality

[@realchristopher4334]

Ah. I hope you would show us how to make discrete version of differential pair. Old school, I know, the mathematics is insane, I also know, but it is especially excellent for learning assuming this channel is about learning how electronics components work and DIYing our own working circuits. All monolithic devices have differential pairs cunningly hiding within them anyway, and is the core of all integrated circuits.

[@TheAudioPhool]

I'm literally working on that video right now!

[@realchristopher4334]

@@TheAudioPhool Oh, whoa! While you are at it, if I may be impertinent as to ask you to (also) show the more advanced stuff, if you know, such as so-called 'current source', 'current mirror', the use of trimmer potentiometre, and feedback to amplify common mode and feed back to the input (Similar to what is called Right Leg Driven. This feedback thing uses proper op-amp and not transistors). These are for the purpose of significantly increasing common mode rejected. I read much about it as to how to make CMRR a bit more perfect in this imperfect world, and simulated it. I even have book written by Douglas Self, who is said to be well-known in the audio world. After all that nonsense, at the end of the day the power of an oscilloscope is the judge. Simulation and reading what other people write are shit as you already know. You coincidentally have an oscilloscope. I have none of that sort. Hence why I am blindly swapping components and by "luck" I hear something acceptable. I do not have too many different values of components, however and sadly. Having said that, I did do the practical side of things. I find that differential pair actually provide more noise compared to non-differential amplifier. I blame the imperfect world! Little did I know that differential pair actually is sensitive and precision device! Ha! Negligible mismatch of resistors, capacitor, transistor, and whatnot is amplified, which is not negligible. Ugh! I do not know by how much noise. I am using headphones, probably my headphones are lousy so they do not reproduce sound accurately. However, I read that noise from low impedance speaker is not audible or is not as bad as that of from high impedance speaker. (Feck ohm's law! I do not know why it happens this way!)

[@ThePhilStudio]

Cool channel! :)

[@FraenkFokken]

Man I'm slowly understanding shit. Though at the beginning I thought you would build a capacitor as the pad :§. This is sick. Just a short question. The resistor you describe at 10:14 acts as a "voltage divider" to the envelope part ? I get that it drains the voltage of the cap. Thanks alot!

[@dragos.andriana]

Any idea of how that could be adapted so that real drums could trigger (or gate?) different things in eurorack setup?

[@gadgetproductions3560]

Piezo pickup / contact mic?

[@erlannderrantem6972]

Well there are triggers you can buy. I think DW make some. Or like Gadget Productions said with a mic. Microphones create small voltages, that you could amplify and run into to the comparator instead

[@jimmy_jamesjams_a_lot4171]

See ‘look mum no computer’. His idea was to take a patch cable, and split the leads, wiring it’s tip to a drum stick with Al-u-min-i-um foil, and with its sleeve wire would simply be wired to another sheet of foil placed upon it to a drum head. Immediate S-trigger for performance. This project is a great jumpstart point for learning DIY electronics!

[@daffygrey]

@@jimmy_jamesjams_a_lot4171 Sounds exactly like how Kraftwerk's original drum pads were.

[@baddriddimworkshop]

Hi there, stupid question others might be asking; will the pink or white foam work to do this (they dont seem to be the same material as the black stuff)? i've got a couple of these to put together for some gueezers, so i'll try that this week (normally i used to use contact mics but with the metal not working so well with a finger), here's a demo of the unit: (hit function used at the end of vid): kzbin.info/www/bejne/o3WynYWQaJ2hfpo reedit: justy tryed it quickly, the pink stuff seems to work just aswell, but, i'm getting more in the tens of megaohms resqistance, not soldered tough, just piled up and put tester probs inside, but still. maybe i just dont have the proper type of foam, allthough it's the ones i got with chips in the special bags... the size of the piece of foam matters too maybe (shurely) the pieces i used are maybe half of yours.... anyhow i'll get intoo this i little better later..... saw this in a book i have aswell, allways wanted to try it, guess you have motivated me to do so. anyhow i didnt look at your circuit but if i'm in megaohm rage, i guess i'll be able to adapt component values... cheers.

[@TheAudioPhool]

Not a stupid question at all! (don't be so hard on yourself) So the pink white foam is not (very) conductive and won't work as well. The basic principle behind how this works is that the resistance of a material is basically the resistance of the cross section multiplied by the length of the material, so by whacking the material we are briefly shrinking the length which lowers the resistance, which we can use electricity to detect and trigger our comparator. So in theory, any compressible material will work with enough tinkering, but obviously if the resistance goes from very very high to very high, that's going to be hard to detect with our comparator! Let me know how it goes :)

[@flywittzbeats4008]

This room is a perfect depiction of where electronic nuts are relegated to by their wives 🤣🤣 thanks for the awesome vids