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-minus-
Joined: Oct 26, 2008 Posts: 787
Audio files: 13
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Posted: Tue May 14, 2013 2:57 am Post subject:
Drum Tone Snare Problem Subject description: Constant white noise |
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I'm breadboarding the Paia Drum Tone circuits and can't seem to figure out the snare. I definitely have the white noise working, but it is constant. It just won't shut up.
I'm running off a +/- 12V supply and connecting all the +5V points to GROUND as suggested on the Paia site, and connecting PIN 11 of the LM 324 to the negative supply. I'm triggering from a logic signal fed through a CGS Gate to Trigger.
I'm wondering if anyone else has got this working or can suggest what I could adjust on the schematic to solve this issue.
Thanks!
Here's the circuit:
http://www.paia.com/prodimages/drumtone.gif
http://www.paia.com/ProdArticles/syndrum.htm
EDIT: OK I fixed it. Seems to run on +12V +5V GROUND but not on +12V GROUND -12V Last edited by -minus- on Sat May 18, 2013 4:42 am; edited 2 times in total |
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richardc64
Joined: Jun 01, 2006 Posts: 679 Location: NYC
Audio files: 26
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Posted: Fri May 17, 2013 7:16 am Post subject:
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Congratulations. You might want to check out my mods further down in this forum.
The "Conga" mod works better than what I did to the SynthDrum. _________________ Revenge is a dish best served with a fork... to the eye |
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-minus-
Joined: Oct 26, 2008 Posts: 787
Audio files: 13
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Posted: Fri May 17, 2013 8:37 am Post subject:
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I did read through your mods on your site actually.
I have the synth drum working. Changed the cap to GROUND with a smaller value. The woodblock is quite fun in a cheap kind of way. The snare sounds awful! A click with a hiss. Maybe it will grow on me. The kick drum sounds more like a floor tom to me. The synth drum with the cap to GROUND removed sounds more like a kick drum.
What I do like about this is its compact design. Gives a lot for so few ICs, and you get to learn a thing or two in the process. I don't expect too much. I just need something simple to experiment with which I can trigger with logic patterns elsewhere. |
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-minus-
Joined: Oct 26, 2008 Posts: 787
Audio files: 13
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Posted: Sat May 18, 2013 12:47 am Post subject:
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I'm looking at your enhanced schematic. It appears the tom is triggered at the same time as the snare. Is this correct? Maybe this would account for my snare sounding a bit cheap. I'll breadboard the tom and see what I come up with.
EDIT: I've just answered my own question. There are some notes here:
http://www.paia.com/talk/viewtopic.php?f=25&t=13&sid=df634d7e60736c1908fc48b5b1c26b21 |
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Biyi
Joined: Dec 06, 2010 Posts: 13
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Posted: Tue Oct 29, 2013 2:34 am Post subject:
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Hi I built the Paia kit, everything seems fine, but when I trigger the sounds from the 4040 0 4017 ic trigger two shots, one when the LED lights and another when you turn off the trigger ... it happens ..? should sound a single shot, as I can fix this?
Thanks and regards. |
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-minus-
Joined: Oct 26, 2008 Posts: 787
Audio files: 13
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Posted: Tue Oct 29, 2013 4:25 am Post subject:
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I had the same problem and built some CGS Gate to Trigger circuits:
http://www.cgs.synth.net/modules/cgs24_gatetotrigger.html
You will need four of these to convert the gates to trigger pulses on all eight voices. I built them onto stripboard. |
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Biyi
Joined: Dec 06, 2010 Posts: 13
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Posted: Tue Oct 29, 2013 7:00 am Post subject:
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Thanks minus .. was thinking about this --- good job and thanks ..
I'll start with the stripboard to prove it. |
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blakeAlbion
Joined: Jun 16, 2020 Posts: 23 Location: Boston, Massachusetts, USA
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Posted: Tue Jun 30, 2020 6:50 am Post subject:
Snare drum too Subject description: Snare drum not responding with +12 and a voltage divider for +5V |
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The notes with the kit say I could just use a single power supply and a voltage divider (in this case I am trying 2x10K resistors) for the +5V rail.
I'm thinking this reference current voltage is working OK for the tone generators but not for the snare gate. I'm going to have to study the snare, it seems crazy to gate the white noise this way.
Regarding the trigger circuits, yes, the design is crying out for Schmidt triggers on those inputs, or simply any direct connection to a logic buffer running up to your full supply voltage. The AC decoupling capacitor on the trigger means the capacitor must fully discharge before the next time you trigger a drum. (which means you can't test the sounds by just brushing +12V across the triggers; the capacitors charge up and get saturated and stop working ) That buffer should be really a directional logic gate that's sourcing on HIGH and sinking on LOW.... But, that brings me to the next issue.
One of the cool things about these resonant circuits is they have a natural response to "how hard they are hit", i.e the voltage level (and pulse width) of the trigger. So what I want for my circuit is to drive the trigger with an op-amp buffered trigger. The op-amp should (another LM324 running on a single-pole supply) be non-inverting and have a pull-down resistor. Then the drum tones will respond dynamically.
(of course some simple noise gate at the audio output would be nice) |
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blakeAlbion
Joined: Jun 16, 2020 Posts: 23 Location: Boston, Massachusetts, USA
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Posted: Tue Jun 30, 2020 7:00 am Post subject:
Snare drum and single supply voltage |
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Okay, looking at the schematic, I will go after the + input of IC2. Looks like the white noise is controlled by bias voltage. The distortion would be horrible, but meh, it's white noise. |
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