In the last entry I described the electrical requirements of LEDs and how to drive them in the context of analog circuitry. When you want to indicate information with the brightness level of a single LED, as in my Transistor ADSR where the LED dir…
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Light-emitting diodes! They're all over our electronic equipment; but what are they all about, really? The underlying concepts are simple, but there are a lot of frequently-asked questions that show there's confusion among hobbyists about how…
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I recently switched to a new cable Internet modem, because the cable company (which provides my home Internet service) assured me that the package that came with the new modem would be cheaper for the same service compared to what I'd been payi…
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I'm sometimes asked about the environmental consequences of modular synthesizers. It's an interesting question with a lot of ramifications, and there's a lot of misinformation circulated. That may be inevitable given the nature of this busine…
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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…
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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…
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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…
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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…
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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…
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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…
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Visit the North Coast Synthesis SDIY page!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…
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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 prop…
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