DR-110 Hi-Hat clone

hey circuit’s burners

Here my schematic inspired by the DR-110’s Hi-Hat drum part who come from this page:
http://www.sdiy.org/richardc64/new_drums/dr110/dr110a1.html

This drum circuit is composed by a mix of white noise and 4 oscillators metallic noise generator.

Sounds possibilities are great !
We can create very cristalline cymbal sounds with a particular setting of frequencies of each Metallic noise generator’s oscillator

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Good ! Sounds seems to look a bit like the CMOS noise bell

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thank you !

yes it use a similar circuit for generating metallic noises with CD40106 oscillators. Then it is mixing with white noise for various charleston’s imitation.

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Sounds really good!!

Did you consider using all 6 schmitt-triggers? I believe the 40106 has 6 of them so perhaps by adding more you could even create a different/richer sound.

And is there a particular reason to use the LM358 with 9V? If you use TL07x over there as well you could perhaps make the build more compact. This one is definitely going on my list and if I manage to get it working on 2 breadboards, I might try and design a stripboard for it :grin: :+1:

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Do you think the white noise could also be something like this? Or does it have very different voltages?

Screenshot from 2021-12-04 18-36-27

This is from the bastl noise squared.

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And the 9 V is coming from a voltage divider between 12 V and ground! It should come from a regulator, if it’s to be used at all. But yes, if the only thing the 9 V is being used for is to power the LM358… why? That can be powered with +12 V, or, again, it could be a TL071 with ±12 V and you could dispense with not only the 9 V “supply” but the 4.5 V bias on the input.

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Screenshot from 2021-12-09 13-13-07

What is this opamp doing? A kind of filter design?

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of course, this is a bandpass filter for clearing RF noise signal, but I have problem with this conception, the sound quality is good but a little too noisy… it’s strange… Maybe I could to amplify before this filter ? (I have amplify after…)

9v can be replace with a 12v power supply, no problem for that !

for moment the module is on my bench work and need some modifications…

have you good results with the output ? do you need to amplify the signal ?

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I’m building this circuit and after a lot of tweaking, I got some pretty good sounds out of it. However, it is a rather noisy module.

Currently, when I turn up the fizzle pot, I get noise in the output when the module is not triggered. Also, the square waves from the 40106 are audible (even if I disconnect its output from the main circuit). I have only added a single 100nf cap next to the 40106 but that doesn’t seem to be enough to stabilize the power lines. What kind and how many caps does it take?

Any other tips would be appreciated. I might have made a mistake here or there, but I’m not sure how to pinpoint those. This is a high-gain circuit so it kinda makes sense that its noisy. Perhaps I should reduce the 100k resistor next to the output opamp?

Thanks a bunch!

@nschagen

Hey, I’m happy you have try this circuit ! :slight_smile:

I have exactly the same problem with HF noise, but I haven’t had time to tinker lately… It’s a shame because the cymbal sounds looks really good…

Maybe we should try to replace the passive filter between the noise generator and the vca by an active Band-Pass filter; I imagine that might solve our problem.

metal1

If you try this before me let me know your results please :slight_smile:

Thank you and have a good building !

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A cap on its own won’t filter noise; without a resistor, the voltage on the cap will change instantaneously. (Not true but true enough.) Caps on power rails without resistors are bypass caps, not filters. They address some problems but not really power line fluctuations. And of course you don’t want to put much of a resistor on the power rail, so this kind of problem’s not simple to fix in many cases.

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