My formal education in audio was gotten at The Conservatory of Recording Arts and Sciences. During my time, there was only one campus (Tempe). We had an SSL 4056 G+ in studio A, which was great fun to use. I’m not really into the “analog mystique,” but I’ll be doggone if there isn’t something neat about all the knobs, buttons, and lights on a large-frame console.

All of us received a copy of the SSL instruction manual, and I still have mine. I haven’t looked at it in quite a while, but I remember it as one of the most lucid and helpful instruction books I’ve read. In it was a gem of a thought regarding troubleshooting. To paraphrase:

“If you run into trouble with your SSL console, you should first be sure that you have not pressed the wrong button. The console happily sits in the studio, day after day, without being moved, kicked, or dropped. It is unlikely that the console has actually suffered a failure.”

The technical writers at SSL may or may not have realized it (I think they probably did realize it), but what they said has generalizable implications for troubleshooting all manner of equipment failures:

While it is entirely possible for any device or component in a device to fail, the components and devices most likely to fail are those most exposed to physical wear of some kind.

This concept was very much on display when I started having problems with an amplifier at my regular gig.

Why Is It So Quiet In Here?

The amplifier in question was the QSC GX5 that runs our FOH mid-highs. I first noticed a problem when we were running a loud-ish show (not really loud, but a bit louder than average). I wasn’t getting enough clarity from the singer, so I “got on the gas” with his fader. I didn’t notice any real improvement, which mystified me. I cast about a bit, looking for a reason why pushing the fader around didn’t seem to be changing things. I happened to glance over at the amp rack, which revealed that the GX5 did NOT have power applied.

(As a side note, the basic audibility of everything in the show, even without the main part of the FOH PA, suggested that the onstage combination of band-sound and monitor wedges was in a good place.)

Anyway…

The GX5’s power switch was in the correct position, so I thought “maybe something is causing the amp to ‘thermal’ and shut down.” I tried cycling the switch.

Hooray! The power LEDs came on, and the amp slowly ramped up to full output availability. I resolved to get the dust out of the amplifier as soon as possible, which I did the next day.

And then the amp wouldn’t start up.

I tried flipping the switch again. Nope. I flipped the switch again, and gave the top half an extra-firm press.

“Click!” The amp started.

I figured that something was just getting “weird,” and that I could live with a little quirkiness. This went on for a couple of months, until a point was reached where the amp just would not get power. I yanked the unit out of the rack, unscrewed the case, and started looking around. Nothing seemed burnt or ruptured, so that was encouraging. I set the switch in the “on” position, and began wiggling wires. (Yes, I was careful to wiggle the wires in a way that would not get me killed.) Maybe there was a short somewhere. Maybe one of the wires to the switch had a break at the crimping. Maybe if I just tweaked one of those wires, it would-

“Click!” The lights on the front panel illuminated, the cooling fan whirred, and the amp was oka-

Nope.

I tried again. I got ahold of the same wire, moving it (and the “tab” contact on the switch) around a bit.

“Click!” The amp came to life. And then I got my tipoff: I heard the sound of electricity arcing inside the switch case. A thin stream of smoke also started to rise from inside the switch. Everything inside the amp was fine, but the user-accessible bit that turned the insides on was not well at all.

Switched Switches

Fast-forward a bit, and the amp was its old self again. A new switch was occupying the space where the old one used to be, and the new part was in much better shape. The old “rocker” had, over time, started to feel very soft when toggled between on and off. This change had occurred so gradually that I hadn’t noticed, but the comparison was undeniable. The new switch’s rocker button had a much firmer feeling of engagement when pressed; the old switch had simply worn down early.

This brings me back to the concept I presented earlier. Of all the parts in the amp, the one bit that was handled at every show was the moving part that allowed power to flow to everything else. Nothing else in or on the amp received more regular, physical stress – with the exception of the fan, perhaps. It was the most likely thing to go. Sure, something in the power supply could have failed. Sure, an actual amplifier component could have popped or fried. It can happen. Amplifiers can lead a tough life, full of heat and high-current.

It’s just that you’re so much more likely to have breakage occur in the parts that move. Of those moving parts, the ones most likely to die are those most subject to the stress of being “handled.” It’s very easy for a $3 switch to stop a $400 amplifier – at least temporarily. Don’t panic.