Positive Feedback ISSUE 36
march/april 2008

The DIY Chronicles: Wire it up and fire it up!
by Gary L. Beard

Number One

An Introduction

As of today, I proclaim myself to be an official Do-it-yourselfer (though it is probably far more accurate to refer to myself as a Do-it-with-helper). As I sit here writing about my leap into the silvery hole of solder-slingers, there is a bit of apprehension that requires, ahem [cough, cough], my amplification:

I, Gary Beard, not-quite-of-sound mind, promise never to feign electronics design or assembly expertise at a level beyond grossly incompetent beginner. Further, I will do my level best never to write anything of a technical nature without having checked the factual particulars first; nevertheless, despite good intentions, mistakes can be made by the blissfully unaware--like me. So please, please, please, never assume accuracy of technical information without confirming it yourself. You've been forewarned!

Prologue

At the outset, I should note that this is unequivocally not a series of "How to get started in DIY" articles. There are myriad fine "how-to" books and articles written by highly knowledgeable and skilled designers/builders, so you don't need a hack like me giving you bad advice. I write articles for audiophile amusement and bemusement. You can expect relating of my experiences, positive and negative (which takes on a whole new meaning in the next installment), as well as helpful hints that might save other virginal DIYer's from false starts. With regard to my own DIY, here is a point of significance: As the H&R Block buzz goes: I have people—experienced people—cultivated relationships with good audio-folks who are helping me bungle my way through building glorious gear. I pray I will not make an electronic mockery of their helpful nature and expertise!

Greek Philosopher Plato once wrote that necessity is the mother of invention. I live by that credo. In fact, when it comes to a new knowledge-acquiring experience, I am the student equivalent of a reverse engineer; I am a "reverse learner"! I hate to study for studies sake; so many times I jump right in and blunder my way into relative success by learning whatever is necessary as I go. I have made a name for myself asking stupid questions and while I might leap before I look once in a while, there is usually a concurrent crash-course of study. I'm lazy, not brainless. Eventually, even an old dog like me learns not to pee on the rug, or at very least, wet the hardwood instead. One thing I won't mess around with is safety. I already knew a little about electricity before I started and I do not—nor should you—take safety practices lightly *(See Standard Disclaimer statement below).

D. I. Why?

If you've read my last couple of articles you know that my DIY journey began in earnest when I caught the fever by rebuilding a 1959 Eico HF-86 tube amp. I did a reasonably good job, but needed much assistance from "my people". I learned how to solder (badly), how to check resistors (easy) and how to equate a schematic to the reality of point-to-point wiring (not so easy). Except for the momentary rush of melting a meter test lead in a shower of sparks when an alligator clip slipped, it was incredibly relaxing. Much time has passed since that minute of exhilaration when I first fired up the old Eighty-Six, yet I will never forget that initial thrill. I knew then that I wanted to feel DIY-high again and decided "building" my own gear would be a grand and adventurous hobby.

 I now have an evolution of projects to be built; each one a bit more complex in terms of my own decision making. A kit build would have been the most sensible starting point, but when good audio-Samaritan, Larry Moore, chief designer of Ultra Fi (www.theultrafi.com), offered to help me build one of his amps as my first project, it was almost too good to be true. His design, a behemoth of a single-ended tube amplifier based on the 845 tube, will be my first "ground up" project and arguably my most exciting anytime soon-- perhaps ever. At this very moment, I am about 80% complete with assembly and should light the wick in the next few days. I can't wait to fire it up!

Once the 845 project is finished and enjoyed for a while, my next build will be a clone of Nelson Pass' Firstwatt F4 (www.firstwatt.com ). The F4 is a Class A MOSFET Impedance converting amplifier and should be a fine solid state companion to my new 845 tube amp. Unlike the Moore amp which had a defined parts selection and a chassis already built (which I am really grateful for), this project will require my involvement beyond strict schematic assembly. Although information abounds on how to build this amp, I will be the ultimate authority on parts selection, wiring layout and chassis design. An Intact Audio (http://intactaudio.com) Autoformer Volume Control and a few other smaller projects are also in the planning stages.

Currently, I am brushing up my knowledge of electrical theory and attempting to gain basic understanding of electronic circuits so I can read the signposts of audio schematics. It is a given that you need reference materials. If you are lazy like me, there are many great audio DIY websites which have links to other websites with fundamental electronic information, specific audio teachings, designs, designers and of course, info on books to buy! These net sites include such well known hangouts as diyAudio www.diyaudio.com , forums like Audio Asylum www.audioasylum.com and Audio Circle www.audiocircle.com , and for you headphone fanatics, Headfi www.head-fi.org . Add to these sites and their links, the free web encyclopedia, Wikipedia, and you have what amounts to net-based "Cliff" notes of audio electronics 101. All these places can be terrific resources as long as you remember that the Internet is the wild west of the information superhighway and everything read comes with a 6-shooter of an asterisk. Don't get your head shot off.

The Beautiful Art

From this preparatory point, the only way to learn esoteric audio design is to keep reading, asking questions and doing it yourself. In my upcoming articles, I might try and stumble my way through entry-level explanations of audio engineering if need be, but since I am just beginning to gain microscopic insight into audio circuits, getting too technical would be an unfortunate mistake and a slap to the faces of the grizzled vets of audio design. They are the true practitioners of this beautiful art; I can only hope to be... So follow along as I stumble down the DIY path from humbled beginner to the victorious uncorking of champagne as listen to my own DIY creations for the first time.

From wiring it to firing it, I can't wait to watch it glow and hope it doesn't blow!

I invite you to join me for the moment of truth.

Gary L. Beard

*Disclaimer: There are lethal voltages present inside audio equipment, so if you are unaware of the dangers inherent in working with electricity and untrained in safe working procedures, you should not attempt any DIY projects, no matter how simple!

I am writing this series of articles for entertainment purposes only and the content within should never be considered a guide or "how-to" instructions for others to build and/or work on audio components. If you are interested in beginning a project, there are many books and other media that cover the basics in a thorough manner. Search them out and use them before you begin!