How to teach myself audio electronics
November 24, 2009 3:19 PM   Subscribe

I'd like to teach myself electronics with a focus on audio. I'm starting with this book. What should I do/read from there?

I have also ordered some prototyping supplies which are in the mail. I know how to solder. I have built one guitar pedal from a kit, which was a breeze, and I've soldered together some microphone cables, but that is the extent of my electronics experience. My short term goal is to build a real analog tape delay. I'd really like to understand all the components and how they work together in order to get a big picture understanding of these things. I want schematics to make sense to me.
posted by Charlie Lesoine to Technology (11 answers total) 30 users marked this as a favorite
Your book link takes me back to this page.
posted by elmay at 3:32 PM on November 24, 2009

I hear Forrest M. Mims' Getting Started in Audio Electronics is a very good introduction. I haven't been able to find a copy. The original version published by Radio Shack is also incredibly beautiful.

Tangent is a true DIY audio electronics teacher/guru. He has some good book reviews and a Getting Started in Audio DIY intro/tutorial. Also the Tangent Tutorials videos are great - they cover the tools you need, various soldering and desoldering techniques and many good and important things. Perfect for watching on an iPod on the bus / train.

I have gone down the exact same path you are starting on, and man has it paid off. This is what I did: I built a small CMoy headphone amplifier. It taught me what an opamp is, and the very basics about supplying power to electronic components and what capacitors can do, strengthened my understanding of voltage, current and resistance, and taught me to shop for parts. A very gentle and practical introduction. It's probably at a similar level as the guitar effect, but if there weren't opamps in the guitar effect, I'd do this one - opamps are very important and enlightening to discover. Also this is such a good walkthrough. Tangent adds just the right amount of detail for a beginner.

I built a PIMETA, a little bigger headphone amplifier. It taught me about more complex builds, and a little bit more about power supplies, like how you get power from a wall socket without killing yourself. Also about output impedance and more about opamp feedback loops, rail decoupling, signal and power ground, positive and negative power rails. Feedback loops are the primary manner of creating analog effects and synthesizers. You shape the feedback signal to get the desired effect - including synth oscillators.

I built a simple TREAD power supply for the PIMETA, which taught me about AC and DC, and put it all in a case which was just enormous fun and highly educational. Magically eye-opening.

I built a small, elegant 41Hz Amp6 20W Tripath hi-fi amplifier. It taught me about a bit higher-power stuff, e.g. current demand and power reserves, and how to select a ready-made power supply. It also taught me about analog filters - very useful! There are very simple and pure capacitor/inductor highpass and lowpass filters on the inputs and outputs of these amps. Mathematically simple, so you know what's going on and can play with the equations and tune components, and also you build the filter, so you really gain a much deeper understanding. This was very important for me.

I built a medium-power Amp4 Tripath hi-fi amplifier with surface-mount components and heatsinked it to a metal case. I powered it with LiFePO4 batteries, which are a pretty cool battery chemistry.

And meanwhile, I hung out on forums and tried to help beginners that I had a chance of telling something new - that really helped the knowledge to stick.
posted by krilli at 5:22 PM on November 24, 2009 [10 favorites]

... and during all this, schematics started to make sense for me.
posted by krilli at 5:23 PM on November 24, 2009

I'm just starting out along the same path of enquiry you are, and I've found that the more schematics you look at the more the start to make sense. I'm interested in building synthesizers, so I stared downloading service manuals from old, out-of-copyright synths and poring over the schematics, trying to get a feel for what went where, and why. trying to isolate the larger structures, differentiating the oscillator from envelope and amplifier.

So I'd say that krilli's suggestions are solid, with the addition that you might also try immersing yourself and waiting for the practice and the theory to come together.
posted by lekvar at 5:39 PM on November 24, 2009 [1 favorite]

Horowitz and Hill's "The Art of Electronics" is one of the best books available for gaining a general electronics background.
posted by ZenMasterThis at 6:22 PM on November 24, 2009 [1 favorite]

What company did you order your pedal kit from? has a really interesting/informative forum.

Craig Anderton's Do-It-Yourself Projects for Guitarists includes instructions on how to convert a tape recorder to a tape echo. He also has (it's been a few years since I read it) the more informative Electronics Projects for Musicians. Some of the parts might be hard to find from the second book, but you should be able to find equivalents online.

Handmade Electronic Music actually did a really good job of helping me understand how audio works in a circuit.

I haven't read any of these, but they might interest you.

It might sound cheesy, but one thing that helped me to understand/build things from schematics was to buy an electronics learning lab from Radioshack. I started out by following the step by step instructions, and then began going solely by the schematic.

Finally, if you've got a decent library near by, look for the section with 70s era Tab books on how to build synths, the synth books seem to cover the different things you can do to sound electronically.
posted by drezdn at 7:38 PM on November 24, 2009 [1 favorite]

Horowitz & Hill is great, and I highly recommend getting a copy, but it's probably not the book to start with (unless you have a teacher or something). It's invaluable once you've gotten an idea of things though.
posted by hattifattener at 8:06 PM on November 24, 2009 [1 favorite]

Do you really understand electricity? The book There Are No Electrons looks uber-cheesy, but it's a great primer. As far as audio electronics, the diy forums on head-fi have a lot of helpful and knowledgeable people.
posted by paulg at 8:30 PM on November 24, 2009 [1 favorite]

No recommendations on books, but I some observations for you, if you are interested.

Schematics identify individual components and their interconnections. They are a documentation convention with their own rules. Not everyone knows all the rules.

The rules are not legally enforced, of course. Schematic designers may faithfully construct a circuit that does not / cannot work. Twenty or thirty years of looking at them will get you to the point where you can read them second nature, but like language, sometimes stuff is accidentally omitted, poorly organized and sloppily conceived. Give yourself a lot of slack if you feel overwhelmed or puzzled.

In my career, when a schematic landed on my desk for a new product, I'd call the designer and chat... 'What are you doing here? Why is this part this size? What are these unused options? Did you know you have a floating input? yada, yada." After a few hundred, they get easier. Community helps. It's like playing guitar.. you get better with exposure and practice, and you learn to appreciate the good ones, and read beyond the bad ones. One day, you start recognizing the impossible ones and the erroneous ones.

Also, FWIW, there are parts in the real world that aren't on the schematics. Thermal effects, printed circuit board traces, wiring and the physical values of those things, at DC and in fields. Things like parasitic capacitance, inductance, series resistance, contact resistance, thermocouple effects. All of these are in a real circuit, and real circuits are in the ambient world of radio and interference. Lots of stuff doesn't show up on the drawing, but does affect the operation of the circuit.

That's what makes this all so fun. One can get to mediocre in a few years. Getting substantially beyond that is a haul.

One more thing... these days, schematics interconnect large symbols (Integrated circuits) more than small ones (discrete components and semiconductors.) The stuff inside those black chips is important, too, but often ignored by designers. It's a whole 'nuther planet in there. Same rules, different scale, highly variable presentation.

TMI. Sorry. Off to bed.
posted by FauxScot at 9:15 PM on November 24, 2009 [1 favorite]

Before you purchase anything, you really should check out Rod Elliot's collection of audio pages. I have read most of the other links that posters have put up here, and they are good resources, but less general than Elliot.

Very good introductory articles on electronics in general and audio in particular
posted by sol at 3:29 AM on November 25, 2009 [2 favorites]

Response by poster: I'm amazed at the depth of some of these answers. Thanks everyone!

@ elmay: Forrest M. Mims' Getting Started in Audio Electronics

@ krilli: The brand new copy I got in the mail yesterday is exactly like the original on the inside, lovingly hand written and illustrated. Thankfully only the cover has been updated.

@ drezdn: Yes it was a byoc envelope filter/fixed wah
posted by Charlie Lesoine at 5:20 PM on November 25, 2009

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