Exponential converters are basic building blocks used in many synth circuits, but for many of us, they are incomprehensible black boxes. The basic concept of how an exponential converter works is very simple; but the simplest possible circui… [Read more]
In my last entry I talked about the rules for simplifying series and parallel circuits. Two resistors in series can be replaced by one with a value equivalent to the pair of them; two in parallel can similarly be replaced; there are other rules… [Read more]
When I started breadboarding the Coiler VCF (see my new videos about it...), I ran into a problem: the design called for a couple of 6800pF (also known as 6.8nF) capacitors, and I didn't have any of those on hand. I didn't want to rush out and… [Read more]
One of the most common beginner SDIY questions is which parts are frequently used and worth buying in large quantities to use on multiple projects. The people who ask this question think they're going to save serious amounts of money by buyi… [Read more]
It is often said that the secret of Taco Bell's success is that they only use six ingredients: refried beans, seasoned ground beef mixture, cheddar cheese, sour cream, lettuce, and corn tortillas. Everything on their menu is just some… [Read more]
Most transistor circuits are quite straightforward. If you look at the schematic of something like the North Coast Transistor Mixer, you can easily recognize common patterns - an emitter follower here, a common-emitter amplifier there - w… [Read more]
It's a fairly common question "What tools do I need to get started with synthesizer do-it-yourself building?" and most people who ask or answer this question seem to think it starts and ends with a soldering iron. That tunnel vision then become… [Read more]
This is Part 11 of a series that started with Part 1. Trying to divide modules into "analog" and "digital" may be a losing game, and it's certainly a recipe for flame wars on Web forums, because strictly speaking, "analog" and "digital" are… [Read more]
This is Part 9 of a series that started with Part 1.Although the Moog ladder and basic two-pole state-variable designs cover very many synthesizer VCFs, there are still a number of other kinds worth mentioning. In this, probably the last article of… [Read more]
You can understand most op amp circuits with just three simple rules. If, through negative feedback, the op amp can bring its inputs to equal voltage, then it will do so. Otherwise, it will drive its output near whichever power supply voltage co… [Read more]
This is Part 8 in a series that started with Part 1. Voltage-controlled filters (VCFs), as I've said before, are critically important in modular synthesis because more than any other type of module, they define the sound of a synthesizer voice.… [Read more]
There's a recurring thread that comes up again and again in SDIY fora, where someone asks how to "mod" an existing device that is not voltage-controlled to give it a CV input. Sometimes this question is asked in relation to a specific product, in wh… [Read more]
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