Simple Twin-T Kick Drum

His lovely Finnish accent is also most as nice as the low-part-count circuit.


Really cool! But whenever I am almost ready to send an order to jlcpcb I see something else and think: oh! That is nice! I will make a pcb and add it to the order xD so everything takes forever!


via reddit, all of the unlabelled caps in the schematic are unlabelled but were all 100 nF in his build.

And there’s a noisy snare/tom that’s a bit similar, a modification of the dogsnakes drum that some people here might be familiar with:


good sound this thing, for the future … i make a layout (only one TL074 but not so easy to do, i hope all be ok)

someone know the origine of the schem, if there’s a name or is it anonymous ?


Yooo, this is awesome!

I pinched it from reddit originally:


I’m still hoping a schematic for that snare/tom shows up at some point. I’m to just reverse engineering one from the strip board…but the way that strip board is drawn really bugs me in so many ways that every time I’ve sat down to do it I’ve decided to do something else instead :smiley:

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i don’t know if it can help, in the begining of his vid he speak about several source for his mix schematic.


Sans titre


Isn’t the transistor without a connection to the collector just being used as a diode?

not sure, i think this transistor make the white noise


Yeah, that’ll be a white noise generator. And it may require checking a few transistors to find a good noisy one. Actually cutting off the collector lead is advised to avoid picking up non noise noise, if you know what I mean.

(But why not just show a transistor symbol with no connection to the collector?)


Yeah, he shares those two sections he pulled from other circuits…but not his full circuit with how he combined them and what he added. That just has to be reverse engineered from the stripboard layout. And if I’m going to deal with that…I’d rather just redo the whole thing from the stripboard. Trying to mentally merge 3 things is more of a pain for me than just reverse engineering from one :smiley:


I tried to redo the schematic from the stripboard (not easy), and it may also not be really conventional :grinning: , but it may help you a little


Dud is the master!!!


it would be necessary that users of schematics check all this

I have checked several times but there may still be errors


Nice! I’ll have to take a closer look tonight then see about giving it a build!

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I screwed something up…but as far as I can tell @Dud’s schematic is looking good so far:

I don’t quite have a board from it yet though:

Like I said…I screwed something up. Several somethings to be honest.

I have my pots on the wrong side (oops). And bigger issue - something is wrong with my power nets because it’s trying to power the TL072 off +5v. I probably left off a flag or something.

After 1AM though so I need to get some sleep.

Sorry to @BlackDeath that we seem to have pulled his thread off topic :smiley:


yes, well, very more reading !

out of the original one, i’ve add cap/bypass cap on power and power reg, and you you add the -12V rail, in his schem it’was only +12 and gnd :wink:

maybe before it is tested put some where “Not verified” for the moment, if someone find it on a google search

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You should put the TL072 Unit C symbol and connect it to +/-12V.

Like this (there are three TL072 here…) :
(Yeah, I like the BAT :slight_smile: … but I solder 1N5817 instead in real life…)


Any idea what the transistor in the top right is for? The fact that there is no connection to some positive voltage on its collector puzzles me. It is connected to the feed back loop of the op-amp on the left, so I guess it can influence that. But it is not clear to me how. Any ideas?