i don’t know if that can help you, in your description, there are similarities with this build
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This design is perfect !
Hey @Dud! I’m building your Twin-T Kick Drum layout tonight (Verified Stripboard Layouts! - #218 by Dud) and as I was building it, I realized, that it’s not containing an LED.
On this photo (My build progress - #2492 by Dud) it seems as it’s wired not to complicated, but I can’t see exactly where the cabels are going… I already soldered all the parts to the stripboard except the wires. Is it still possible to add a signal LED?
Would it be possible to use the 5 Volts of the trigger to light it up?
(I’m not getting what @Plop is doing in his layout 
)
Thank you for your help and thank you for posting this Layout!
Good night
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Infact i did this (but i think that another way but both works )
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Amazing, thanks a lot! I even have some spare 2N3904 at home from the simple Hi-Hat and Snare build. You helped me there as well… 
Best wishes
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If you’re going to do much more building, get yourself more than just a few spare 2N3904s. At Tayda they’re 2 cents each and if you buy 50 of them, you’ll use them.
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I also build this with a slight modification from Dud’s layout (only eurorack power header) but so far it’s not working 
I hear a tiny click, but nothing else, when I trigger. It gets a bit louder when I turn the distortion knob to the right and the tone knob does also something, but decay and frequency do nothing. I suspect it’s something with the twin-t itself, but I can not find it… I checked with the layout multiple times and measure +12 and -12 volt at the TL074, like it should be… maybe you can spot something I missed… 
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On the stripborad the first line under the IC is +12V, and you have your bypass cap connected on it intead of GND ? you don’t forget a line somewhere ?
but with the eurorack socket add i don’t really know what you’ve done, maybe i miss something
yes i think you inverted the cap and the wire to +12V on chip, with red and black line, the ic have only power throught the cap, and is also connected to GND
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The power lines are the same as in your layout. I only connected the eurorack connector to it on the right.
On the bypass cap: I think I got it correct, but it’s hard to see on the photo. It looks like it’s the cap connected to +12V, , but that is just the wire to the VCC of the Opamp. The cap is from VCC to ground, as planned the wire is thick and on the left, the cap has a tiny wire and is on the right.
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ooooh yes i see it , sorry
it’s difficult to see but the top of the white cap is on the same line that the white wire ?
I was also wondering if the 1k here in your layout should not go to ground like in the schematic? Or am I looking in the wrong place?
EDIT:
I see it, it’s the other 1k!! All good, sorry!!
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I found the issue! Two rows of the Stripboard were connected and shorted out the 1Meg resistor :-/
I could not see it by eye, but they were still connected when I removed the components. I cut them with a knife and now it works! I think someone here in the forum mentioned a similar problem with another module (maybe @Jos ?). So, always check your strip boards!! xD
Such a great kick!! 
Thank you, @Dud and @Krakenpine
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Yep, was a frustrating thing, I could not see it by eye and only measure that there was a short using a multimeter.
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Hey folks, I built this kick drum late last year and use it often, however I find that if I have it anywhere near my Arduino based midi trigger module, it really picks up digital noise from it. Do others find this? I’ve had noise problems with other twin T circuits (snare/tom) actually picking up other sounds being generated near them and outputting 180 degrees out of phase which then cancels it out, so is this a feature of twin T drums? Are they just inherently noisy?
Well, it’s basically a very highly resonating bandpass filter, so yeah, there’s quite much gain in that sense. Also in this theres also gain in the input stage (which maybe should be redesigned) and distortion circuit. But I also think, that the Arduino-module is giving out more noise than it should if it’s affecting modules next to it.
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I just built the module and this is my second time building it, first time worked fine but this one I can’t get any sound out at all. I checked to make sure it is receiving gate/trigger signals which it is, but still nothing is being outputted, any help?