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adamstan
Joined: May 23, 2008 Posts: 34 Location: poland
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Posted: Mon Nov 21, 2016 12:27 pm Post subject:
Simple DIY analog hihat module |
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Hi
Last saturday I've built very simple analog hi-hat module. I made it on perfboard, using parts that were laying around. It is similar to circuits used in analog drum machines, like DR-110 etc - four squarewaves mixed with white noise, then little-resonant HPF. Trigger/EG circuitry is loosely based on Simmons, and VCA is simple single-transistor Korg circuit.
Schematics:
I didn't have any Schmitt inverters at hand - that's why square oscillators are built around TL074 opamp.
As you can see, signal from footswitch input is converted into positive trigger pulse, and fed into trigger input as well. That way pressing down the footswitch ("closing the hihat") produces sound too, instead of only switching decay time.
Module is meant to be played from pad and footswitch - I built as an expansion for my electronic drum kit based around polish EDD5 analog drum synthesizer from late '80s. The "brain" has external audio input, and power output (+-15V on DIN5 connector), so they integrate nicely.
Here is short demo of whole kit. First half is from camera mic, second - from line in. Please forgive my sloppy playing - I had quite long (over 6 years) break from playing any kind of drums.
https://www.youtube.com/watch?v=gjRsVhy--vM |
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tasteless
Joined: Feb 18, 2013 Posts: 7 Location: Australia
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Posted: Fri Nov 25, 2016 1:47 am Post subject:
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COOL !
Nice choice of circuit elements - I have been intending to do something similar for a long time But , other stuff keeps getting in the way.
That Simmons switching looks VERY interesting. |
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Ayab
Joined: Oct 27, 2015 Posts: 180 Location: London, UK
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Posted: Tue Dec 06, 2016 7:01 am Post subject:
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Thank you for sharing your design. Great little circuit. I am interested in building this as I am beginning to understand schematics. Not sure I am yet able to do the layout though but will give it a try when I have time. |
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adamstan
Joined: May 23, 2008 Posts: 34 Location: poland
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Posted: Wed Dec 07, 2016 4:20 am Post subject:
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Don't forget to put decoupling capacitors on power supply pins for each chip (100n to ground should be OK) - they aren't drawn on schematics. |
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Ayab
Joined: Oct 27, 2015 Posts: 180 Location: London, UK
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Posted: Wed Dec 07, 2016 6:02 am Post subject:
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Ok will add a note to the schematic thanks for confirming that |
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