![]() ![]() My replica of the drum is powered by ☑2 V coming from my Eurorack power supply, while the original drum machine used ☑5 V. There are a few things to consider when comparing the model against the real circuit.įirst, my circuit uses resistors with a tolerance of 1%, while some of the capacitors have 5% and others 1%. In the beginning of this post, we saw a picture of the circuit I built to use as a reference. ![]() But before doing that, let us take a look at how this model matches our real kick drum. We could create a more efficient model by simplifying all the circuit sections according to their behavior. In our previous analysis, we discovered that practically all semiconductors in the circuit are used as switches. On my computer, it takes 3.5 s to run a simulation of 4 s.It simulates 7 semiconductor components (5 transistors and 2 diodes).It requires solving 7 linear systems of equations and 1 nonlinear system.Here are a few insights about this simulation model: (Again, because it is a low frequency, you may need to play it using a decent sound system.) We can listen to the sound produced by this simulation in the following audio output. After that half-cycle, the resonator oscillates at the base frequency until the energy dissipates according to the set Decay. This half-cycle is about twice the base frequency of the resonator. In summary, we can see from the output that there is a small positive “click” followed by a negative half-cycle of a sine wave. This introduces in the resonator a pulse of –15 V (Section 7 output), and at the same time, the frequency of the resonator changes when reintroducing the 47 k resistor. When the resonator is about to complete half a cycle (which is around 4 ms), the pulse of Section 5 goes low. The capacitor of Section 7 starts charging to +15 V. The 4 ms pulse of Section 5 bypasses the 47 k resistor of the resonator by short-circuiting the transistor of Section 6. This makes the resonator start oscillating. We can see that after the trigger, the resonator is excited by a short pulse (Section 2) whose amplitude is given by the Accent amplitude. Here you can see the schematic I made for the bass drum: (Download this zip folder for all the necessary files to experiment with the code in this post.) Later, we’ll simplify and optimize the model to compare the resulting sounds of the different versions against the 808 kick drum hardware. We’ll start by creating a component-level model to get an accurate reproduction of the behavior. In this blog post, we are going to model and simulate the kick drum, one of the most emblematic drums of the 808, using Wolfram System Modeler. (Other drum machines may use samples, which are recordings of existing drums or percussion.) Over the years, I’ve been analyzing drum synthesis circuits, and the fact that all the drum sounds are generated by simple electronic components made the 808 very intriguing. If you are interested, you can find many videos about the 808, including this trailer for the 808 full-length documentary:Īll the 808 sounds are generated using analog electronics. For over 40 years, it has fascinated musicians, who have used this drum machine in their music. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |