Let’s continue our deep dive into analogue drums with a look at something even earlier – the Korg KR-55. This is a preset drum machine from 1979. It uses a Read-Only Memory (ROM) to store patterns, but it has no processor, unlike the Boss Dr. Rhythm we looked at. Consequently the digital side of this […]
The TR-909 uses a hardware implementation of an LFSR as its noise generator. We’ve dealt with LFSR noise generators in a few other articles, but we’ve only looked at firmware implementations, so it might be fun to see how the same thing is done in hardware. The circuit is composed of three parts; the shift register […]
The Electric Druid range of chips now includes four noise generators, so the table below summarises the differences between them to help you select the best chip for your application. White Noise Outputs Pink Noise Outputs Digital Control? MN5837 replacement? NOISE1B 1 0 No Yes NOISE 2 1 1 No No PENTANOISE 5 0 […]
It’s been around ten years since I developed the original Druid NOISE 1B chip to produce good quality white noise. Finally it gets an update, and the new NOISE2 chip can produce pink noise as well as white noise, so there’s no need for external “pinking” filters. Here’s what it sounds like, white noise and pink […]
In general, we’re trying to keep noise out of our circuits. Somewhat inspired by this thread on DIYStompboxes, I thought it might be fun to build a circuit that could generate that “vintage background noise” sound so that I could make things sound like they’re being played back off a phonograph cylinder or an ancient […]
A pure white audio noise generator using an 8 pin PIC 12F675 This pages describes a simple digital noise source that produces pure white noise over the whole audio band – out to more than 40Khz, in fact. With filtering, you can derive pink noise and other colours. The circuit diagram included below was developed […]
The linear feedback shift register is one of the most useful techniques for generating psuedo-random numbers. I’ve used this method for creating noise generators and as an element in the random modulation generators I spent a long time developing for my Protowave synth. If you’re not really clear how an LFSR works, have a look […]
