We live in interesting times. For many years, people have been wondering if it would be possible to reproduce the old CEM (Curtis Electro Music) and SSM (Solid State Music) chip designs from the late 1970’s and early 80’s. We’ve always been told that there wasn’t enough interest to make such a thing commercially viable, […]
Articles
What is a “Multimode filter” anyway? It’s a filter which can provide more than one response. So it might offer a choice of 2-pole or 4-pole lowpass responses, or it might be switchable between lowpass and highpass, or it might have lowpass, bandpass, and highpass outputs. There are basically three techniques for building multimode filters, […]
This article is a look at sub-oscillators, a common tactic for fattening up the bottom end, particularly in synths with only one oscillator, or only one oscillator per voice. Classic examples include the Roland Juno 106 and SH101, and the Korg Polysix. More recently, sub-oscs turn up on a lot of modern analog synths since […]
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 […]
Can we make a modern reproduction of the classic top octave generator / top octave synthesiser chips of the 1970s, as used in classic string synths and combo organs? What would be involved? Can we improve on the originals in any way? This page is a summary of what I learned by doing it. A […]
This post is a place to gather my thoughts about one of the most important parts of synthesizer design: the timbral evolution of sounds. It also presents the results of my analyses of some classic synth sounds. There have been many methods developed over the years to achieve timbral evolution. The voltage-controlled filter is the first […]
To celebrate the 2016 return of the CEM3340 chip, I thought I’d do another page in my series looking at how various synths implemented classic synth chips (the others being CEM3320 Filter designs and SSM2044 LP Filter designs). This is especially useful right now, since many people have bought a few CEM3340s or V3340s or AS3340s for their […]
The Roland SH-101 is a late-era analogue monosynth which uses a microprocessor to perform keyboard scanning and various related functions, much like the Sequential Pro-One. Since the original uP is a 40-pin DIP, it would be possible to replace it with a more modern 40-pin DIP uP, like the PIC 16F777, or with a modern […]
Flangers are generally regarded as one of the most complicated pedals to build. A typical design has tons of chips and lots of circuit elements. Flangelicious isn’t like that. By using a microprocessor to generate an LFO-modulated clock signal directly, we can get rid of a lot of the non-signal path stuff and add features whilst we’re about it. […]
Recently I’ve been working on a four second digital delay with tap tempo and delay trails. There are lots of digital delay projects already, but the vast majority of them are based on the PT2399, which limits both the length of the delay and the sound quality. A quick summary of the features: 0 […]