Valves and Hooks

One of the joys of having a bit of time off is that you can follow an interesting idea or thread to its illogical conclusion. There’s no concern about deadlines, work products, or meetings to snap you back to reality, pulling your head out of whatever cloud (private, public or hybrid) it was in at the time. Most recently, the interesting idea was thinking about how everything I learned in my first electrical engineering course can be explained by rock and roll, and the illogical conclusion involved the words “lethal voltage.” But I’m getting ahead of the story.

Amplification and sound reinforcement has always been a sideline interest. I’m pretty sure it started when I was taking clarinet lessons and always had fifteen spare minutes on either end, waiting in the music shop, to look at the electric guitars and basses and dream of being Ace Frehley or Gene Simmons rather than Benny Goodman (and if anyone comments that Billy Joel’s Scenes from an Italian Restaurant has a clarinet solo, I’ll force you to listen to “Lite FM” until your ears beg for mercy). First real hook was doing sound for a school event in the gym that let me run microphones and house music. Three years at WPRB-FM doing commercial production, engineering, and listening to everything from bluegrass to Blue Oyster Cult helped; at the same time I was taking intro level physics and EE courses and learning how the sounds were actually produced and amplified. The hook was set, deeply.

Two events propelled me forward in my love of all things loudness-related. First was the epiphany of understanding how an electric guitar produces sound. In my high school-physics addled brain, this made no sense — a steel string vibrating without microphone or any direct electrical connection to an amplifier produced sound. Throw in a real physics class taught by someone who understood magnetism (and therefore made it part of the curriculum) and a lot of time working on balanced inter-studio lines at the radio station and I finally “got” how pickups work, and in reverse, how speakers produce sound. The second event happened about three years ago, when Bubba and I were auditioning effects pedals at Sam Ash (OK, he was auditioning, I was paying for them). Each effect was merely shaping the waveform coming off of the guitar, and looking at the schematics I saw things that jolted quarter-decade old memories of Professor William “Supersonic” Surber, one of the highest output, greatest signal to noise ratio teachers I’ve ever had.

Everything I learned in that class could be explained by an effects pedal or an amplifier. I now wish I’d paid better attention every time he said “we used to do that with tubes.” One of my longer-term projects — setting the next hook — is to do a short lecture of basic EE circuit forms using nothing but an electric guitar, effects pedals and an amplifier. Let’s face it – learning about voltage controlled filters is not something everybody wakes up and wants to do, especially when it’s mid-November, you’re hung over from a Thursday night party, and you’re worried about the differential equations problem set you didn’t finish yet. I’d teach “VCF via FCA” – that is, Frampton Comes Alive, using the wah effects on Show Me The Way to demonstrate how a voltage controlled filter works. We’re well past visual or literal learners; we’re into audio processors.

Back to that too much time on my hands bit (modulo the Styx reference, thank you). I’ve discovered Ted Weber Loudspeakers and his tube amplifier kits. No pre-printed circuit boards, no step by step instructions. These come with a bag of parts, some basic construction foundations, and enough braided wire to hang yourself. You must love any website that warns potential builders to be comfortable working with potentially lethal voltages. Men will cook if dangerous open flame is involved (this explains tailgating, winter time grilling, and s’mores) and men will use science if other lethal side effects are possible (hence McGyver, James Bond, and audio engineers). I will wield Ohm’s Law like Thor’s hammer, but in a gentle way.

I talk a good game but I’m still a nerd at heart, and I ordered some basic literature on tube amplifiers just to refresh old EE knowledge and help me decide if I’m going to be paying the electrician and sheetrock contractor to repair whatever damage I cause when I power on my kit. The first book on the reading list is Morgan Jones’ Understanding Valve Amplifiers. I had a bit of trepidation, because (a) “valves” is both a very British and very dated (not always redundant) phrase for “tubes” (b) the author refers to himself in the third person in the intro and (c) he uses “whilst” in each of the first three sentences. But later in the first chapter, he is explaining how you might be fooled doing something as simple as measuring the current going through a light bulb, because the resistance of the bulb increases dramatically as it warms up. This is why light bulbs fail when hit hit the light switch: they get the most current going through them when cold.

It was one of those “so that’s how it works” moments. I’m hooked. Again. Time to clean up the soldering iron and clear a workspace, because I’m ordering the kit.