Building a Synthesizer, Introduction

The World of DIY Synthesizers

Posted on February 20, 2023

I’m building a synthesizer. I like synths and I like electrical engineering, so it seemed like a natural fit. But I’m not at the point where I’m ready to take on the design from scratch, so I wanted to find a kit. There are a lot of choices! In this post I’ll review some of the options and explain how I settled on a kit to buy.

A synthesizer is a function which computes an audio signal over time, given some (usually keyboard) input. Sometimes, as with a modern digital synthesizer which contains a general-purpose CPU, it does this using the standard model of computation which we programmers are all very familiar with. But in an analog synthesizer, it does this computation using an analog computer, which is a different model of computation that is not so common today. So over the course of this series I will also look into alternate computational models and think about what we can learn about computation from them.

I’m also going to be writing what amounts to a laboratory notebook as I work. The point of building this kit for me is to learn about electrical engineering in general and the construction of analog synthesizers in particular, not to get soldering practice. This may be more detail than many readers want! But I do think that for people who are building these kits it can be really helpful to hear what others discovered while building them, so I have a lot of detail and digressions in the series.

Modular Synthesis

From a DIY synth-builder’s point of view, a modular synth (see the glossary for a definition of “modular” in this context) makes sense because they keep the various parts of the circuitry well-segregated; instead of a big mass of ICs which are used for multiple different features within a synth, each module stands alone, which means that you can understand how each part works more easily.

From a musician’s point of view, modular synthesis may or may not be your thing. It’s certainly not mine! Programming a sound on a modular synthesizer is roughly equivalent to programming on the ENIAC:

The initial design of the ENIAC did not use anything like the software we know today. It was basically an assembly of “functional units” that were wired together in a particular way for each new problem. If you wanted to do a multiplication after an addition, you would run a wire from the multiplier to the adder.

As a musician, I far prefer playing software instruments. I have the musical attention span of a squirrel on “Mach 6”, and I like to be able to change from song to song at a whim. But as an (amateur!) electrical engineer, I can learn a lot from building hardware, especially if the circuits are fairly easy to understand. So a modular synth is a good fit for this project.

Some Options for Synth Kits

There are, thankfully, a number of choices of synth kits on the market, and there is a lot of variety in terms of what you’re building, what techniques you’ll use to assemble it, and what you’ll learn in the process. Here are some kits that I considered.

It would be a mistake to buy one of these kits based solely on the features of the synth. As I noted above, I am more interested (for this project) in learning about electronics than ending up with a synth I want to play every day. So I spent some time reviewing the manuals, which are mostly available online, and seeing which had the most engaging documentation. There is a wide range between “barely documented” and “a mini-course in electrical engineering” represented here.

Moreover, there are many resources which could make a “make or break” difference in terms of whether or not you’re able to successfully complete the kit, especially if you take on one of the more challenging kits. These include message boards and YouTube channels. It’s worth spending a little time to review what resources will be available to you should you need a “lifeline.”

At any rate, I ended up choosing the mks x es.EDU for a couple of reasons. First, my desire to learn about how the underlying electronics worked really narrowed the choice down to “those kits with the best manuals,” and that meant either mks x es.EDU or North Coast. Second, the mks x es.EDU system is just that: A complete set of modules designed to work well together.

The North Coast modules, by contrast, are better in terms of the number of features they provide, but are much more expensive (the oscillator module alone lists at US $342, whereas an entire mks x es.EDU system goes for €630.00) and are not designed to be purchased as a “system” which you can assemble and play. They’re modules, which you might want to use with other DIY modules or with modules you buy from other vendors. They are probably a better fit for people who want to build the synthesizers for music that they play, rather than people are primarily interested in building a synth to learn about electronics and synthesis, although I think both groups would enjoy them.

Ordering from Latvia

Although there are US dealers for the Erica Synths gear, they seemed to be out of stock of the entire mks x es.EDU system when I looked, so I bought mine directly from Erica Synths in Latvia. To my surprise and delight, my credit card company did not immediately reject the order. Everything went through, and shipping was quite fast! In less than a week, the box was at my door, in good condition and ready for assembly.

A box containing the synth kits

Little boxes containing each module kit

What You’ll Need, Besides the Kits

Although the mks x es.EDU kits are “complete” insofar as they include printed cirucit boards, components, panels, and (optionally), an enclosure, you will need additional tools and materials to assemble them.

Also, there will be additional parts and materials necessary for some of the individual kits; I’ll discuss those in later posts.

In the glossary I will explain some of the specific terminology and technology common in the modular synthesis world. If you already know about all of that, you might want to skip ahead to The mki x es.EDU DIY System


Each post in this series will include a “Resources” section with some useful links to places to learn more about the material discussed within the post.



Tags: synthesis, diy, electrical engineering