North Coast News

Exponential converters and how they work
2018 Oct 12th

Exponential converters and how they work

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]

Level up on circuit simplification
2018 Sep 22nd

Level up on circuit simplification

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]

Combining components for new values
2018 Sep 19th

Combining components for new values

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]

Common parts to keep in stock
2018 Aug 23rd

Common parts to keep in stock

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]

The vanity of "Having A Lot Of Parts"
2018 Jul 30th

The vanity of "Having A Lot Of Parts"

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]

Transistors for the Perplexed
2018 Jul 8th

Transistors for the Perplexed

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]

Tools for getting started with SDIY
2018 Jun 26th

Tools for getting started with SDIY

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]

One minute op amp analysis
2018 Mar 11th

One minute op amp analysis

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]

Voltage control modifications
2018 Feb 25th

Voltage control modifications

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]