Bass Drum

Grumble

I am working on a drum synthesizer, but I have to do it my way Rolling Eyes

The first part (the software needs some more tinkering, the hardware is incomplete) is working, and I am so enthusiastic that I had to publish this part...
Looking at the schematics, of course there is an Arduino (clone) Nano and three more chips (the opamps not counting, they are just there for getting the right voltages out.
First there is the AD9833, a Direct Digital Synthesizer from Analog Devices.
This can put out sine, triangle and square waves (not simultaneous) which is clocked by the 16 MHz from the Arduino.
So I can change the waveform, and I can set the frequency and the phase.
The phase (and that is "new" for me), is used to give an extra click at the start of the drum sound. This is set with a potmeter, so I can choose more or less "click".
So this is the sound generating part.
The second chip is an AD5545 from Analog Devices, this is a dual 16 Multiplying DAC, so the signal at the output is multiplied by the value of the DAC register and devided by 65535.
This is used to set the amplitude of the drum signal, I also make a ramp with it.
The third chip is an ATtiny13, which is used to generate digital noise, for another type of drum or hi-hat, to be determent.

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ixtern · Joined: Jun 25, 2018 Posts: 145 Location: Poland

Interesting. Although bass drum sounds little anemic. Longer decay and some transients (don't know how) would be helpful.

Grumble · Posted: Tue Nov 26, 2019 5:12 am Post subject:

Yes, dull and flat, if you listen to the first hits, I agree, but these sounds come directly from the DAC, are sine-waves and no filtering whatsoever.
But later on I change to triangle waveform and back to sine wave, add a click and modulate the signal.

I just listen to it on an iPad, but that sounds terrible, you will need some decent speakers.

MapacheRaper · Joined: Feb 15, 2018 Posts: 166 Location: Spain

Once you get of of the box to achieve the results by different ways is where the magic happens. I like the idea. I wonder how much costs that AD chips, tho!

Grumble · Posted: Fri Dec 13, 2019 12:02 pm Post subject:

The AD5545 retail value is depending on the type between 10 and 12$ the AD9833 will cost you about 2$ soldered on a breakout board.
But I get them for free.

Grumble · Posted: Sat May 16, 2020 12:59 am Post subject:

In the end I dropped the noise part all together. And this is the final product. The bass drum is on the right next to the sequencer and it’s labeled iDRUM

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