Notes and Links for Beginners Building Their Own Audio Equipment

This article is written for beginners who wish to get into the DIY aspects of the audio hobby, but don't quite know where to start.

First, you need to assess your level of experience with electronics. Do you have any familiarity with basic concepts like Ohm's Law, components (transistors, tubes, resistors, capacitors, etc), wiring, soldering? If not, there are many resources to help get you going. You just need to start slow and be patient. Here are some resources to bootstrap you:

• Some basic electricity theory and Ohm's law at Sparkfun

• How to read a schematic also at Sparkfun

• A good Instructables article on basic electronics

• Basic transistor theory, also at Sparkfun

• Vacuum tube theory at Electronics Notes

• A Learn to Solder Kit on Amazon - practice soldering without hurting anything

• And about 10,000 other websites and YouTube videos - Google is your friend!

If you have some experience with the basics (or even if you are an electronics guru without any audio background), here are some more advanced resources:

• Introduction to amplifiers at Electronics Tutorials 

• A good discussion of amplifier classes, also at Electronics Tutorials

• Designing Audio Power Amplifiers - Bob Cordell's definitive work on power amps

• Small Signal Audio Design - Douglas Self's book on low-level circuits (e.g. preamps)

• How to Build Custom Speakers at Instructables - a decent introduction with some good references

• And, of course, the Speaker Forums at DIY Audio

• Any topics that interest you in the DIY Audio Forums - there are thousands of posts (which can be a time sink)

• Also, see the Useful Links section on the home page.

• For an excellent deep dive into all things related to electronics, I recommend The Art of Electronics 3rd Edition. That is a link to the PDF version, but I recommend buying a hard copy, available from Amazon and others. Warning - it is huge - over 1200 pages, but is the most comprehensive book on electronics ever produced. It is well written and approachable. It is used in many college courses. If you can work your way through even 50% of the book, your knowledge of electronics will be on par with many experienced engineers.

DIY audio is not particularly cheap - you can buy adequate prebuilt consumer HiFi gear on a budget. But that is not the point. The hobby is more about building the best gear you can afford, and being able to tweak and experiment as much as you like in order to achieve as much of the illusion of live performance as possible. That, plus the satisfaction that comes with creating something on your own. For several hundred dollars, you can build a superb power amp that would rival something in the 3-4,000 dollar range, for example. And I should mention that for a lot of people, it is just plain fun.

I won't go into speaker building just yet - that requires (most often) woodworking skills and tools, so I'll start with working with electronic components - a good starter project would consist of a PCB and a complete kit of parts. If you can't get a complete kit, you'll need to have a BOM (bill of materials) and start chasing down components on Mouser or Digikey.

What you'll need - the basics:

• A good temperature-controlled soldering iron/station. Something like this.

  • If you are going to tackle anything with surface mount devices (SMDs) which I don't recommend for beginners, you'll need a hot air soldering station

• At least 1 and preferably 2 digital multimeters capable of reading true RMS - these need not be expensive. One example.

• A circuit board holder. I use this one.

• Small diagonal cutters and needle nose pliers

• Wire strippers

• An adjustable bench power supply to test your project. I would suggest looking on eBay for a used example like this. (note: this link might become obsolete, but the GW Instek supplies are pretty good).

• Hookup wire suitable for the project - I like silicone insulated wire in various gauges.

• Miscellaneous hardware like spacers and screws to mount stuff - assortments on Amazon.

• Medical grade isopropyl for cleaning flux off boards

• A source of test music - could be an old CD player, a computer, tablet, iPod, or even a cell phone

• Some test speakers/headphones (and a test amp if you are not building one) or speakers with built-in amps - some way to listen to what you are building

That's enough equipment needed to assemble some circuit boards and do a bench test. People might argue with the idea of a bench power supply for beginners, but I think it is a necessity. Much of the above can be obtained from Amazon, and there are usually multiple types of each category, so you can shop for the best prices.

As you get into it more, you'll probably want:

• An oscilloscope. Prices for decent scopes continue to decline. I bought a used Tektronix 465 (working) for $100. But there are some interesting new small tablet scopes like this one.

• A Variac - for power amps. It is helpful to ramp up the A/C input to make sure your circuit will not exhibit magic smoke prematurely. Alternatively, you can use the "dim bulb" method which consists of wiring an incandescent bulb (typically 60-75 Watts) in series with the AC input. This will limit the current in the primary circuit.

• A drill press for working on cases and chassis

• A bin of parts (which you will naturally collect over time)

• A heat gun for shrink-wrap tubing

• Crimping tools for connectors, both insulated and non-insulated

• An A/D converter for distortion measurements, or a dedicated audio analyzer (very pricey)

• A signal generator