I was just about to order components for the two last Cat Girl Synth modules. Got six PCBs from Elby-Design and the last two are the Bi-N-Tic filter (switched capacitor) and a Quad Drum Simulator that very much looks like the PE drummachine.
CGS318 Drum Simulator
Also I would need a gate sequencer and I have some ideas, and Bartons Step Rythm module, which unfortunately has just two outputs. Maybe one more …
BMC039 - Step Rythm
Hey, I just built this and ran into the same issue with the white noise stuck on. There is a trace that needs to be cut between the 100K and the 4n7 by Q2 and Q3. With it connected, it is bleeding voltage into the trigger and keeping it on. Excuse the crude paint job.
Also, the 2 100k resistors in that area are originally 1M in the schematic, and both Q are connected to 12v. Goosing them up with more current does drive them a bit more, but you can play around with those values. And Q1 is tied to 5v in this layout, but is tied to 12v in the schematic. I switched it back to 12v, but it didn’t seem to make much difference, if any. The gate still works as it should.
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Wow excellent! I’d kinda given up on the noise and Snare! Will get back to this one when I get back from vacation! Thank you so much for taking the time to report your findings. I’m as ever super grateful for this community! 
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Isn’t that just how a nose circuit works though? They’re usually just ON, you don’t need to trigger them. You just open a gate when you want white noise, like for a snare or cymbal, and close it behind you when you’re done. I’m not familiar with this circuit, so maybe I’m wrong here, but it sounds like the nose circuit is working correctly.
My problem at the moment is that I have lost my “Fat Drums” version of this, not the KiCad but the build has gone AWOL, and I think I know what’s wrong with it to maker it work 
Got to be somewhere!!!
Rob
And yes I have looked in both the last place I had it and in the place where I will find it, it’s in neither.
Yep, it is supposed to be opened by the gate like any normal white noise. In this one, it triggers the tom and white noise together at a specific point to combine both. The problem is that the snare specific gate is stuck open (held with 12v) without that trace cut. Otherwise, the layout is great and thanks to all that helped make it!
All that is left for my build is weak white noise on the snare trigger. 12V on the snare trigger sounds fine. 5v is useless. I’ve probably got the wrong value resistor somewhere.
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You built two of these, so you should tweak one of them out, variable pitch, noise filter/decay, etc. 
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To tweak the snare output, you can alter the value of that 100nf filter cap that comes in the direct path of the “snare” trigger and goes to the base of Q1 to some larger value, like a 4.7uf. I did that on my build and it sounds much better now.
I also added a snare decay by running a resistor tied to a 1n4148 diode going to a pot wired as a variable resistor that runs to ground. It can tie in off of the cathode of diode that connects to the Q1 emitter. I honestly don’t even remember the value of the resistor I used, it just has to be enough to prevent runaway noise when the pot is at 0 ohms. I think I used a 100k pot…maybe.
Last thing I want to tweak is the hat sound. I am playing around with trying to create a trigger decay like with the snare, but the balance with the snare decay part of the circuit is tricky, and like Sam mentioned, they both sound the same it you trigger it off the snare decay part of the circuit. I’d like to find a way to get a little thunk and chunk into it and make a quick decay on it at or near the current trigger section, but I doubt it will be do-able with just modding a few things on the current config and without buffering.
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