Photo by Ariel M. Goldenthal
Players buy guitars looking for feel, for tone, for inspiration, and for just a little bit of magic. Sometimes that magic is in the form of the mojo that resides in a great pawnshop find. And sometimes the magic is in its resemblance to a guitar hero’s chosen instrument. That’s just as true whether it’s a vintage Martin flattop like the one Stephen Stills plays, a Jeff Beck or Eric Clapton signature model Strat, or a Gibson archtop. Musicians looking to buy a great old jazz guitar immediately think about the gear and tone of their guitar heroes: Charlie Christian’s ES-150, Wes Montgomery’s L-5, or the ES-175s favored by Jim Hall and Joe Pass. They all played Gibson archtops, the classic jazz box.
But what amps did those jazz guitar heroes use? Gibsons? Not usually. For the most part, they used Fender amps, most often the Twin Reverb. The result is that while Gibson archtops are valued by players and collectors alike, Gibson amps aren’t. And that’s just as true of the low-power amps.
Just as guitars become icons because of their association with great performances, so too do amps. That’s where the difference in perceived values between Gibson and Fender starts. And it’s where Clapton and “Layla” figure in. If you Google “recordings small amps,” one of the first pages to show up will be “10 Huge Sounds Recorded on Small Amps - Gibson.” Click, and you’ll be taken to a gibson.com page with that title where you can read about amps used on Clapton’s “Layla,” Joe Walsh’s “Rocky Mountain Way,” Aerosmith’s Honkin’ on Bobo, Billy Gibbons’ “La Grange,” and Jeff Beck’s “Cause We’ve Ended as Lovers.” They are all Fender Champs. And yes, you read correctly, all this information is on gibson.com.
It might be tempting to conclude that this is proof that Fender Champs are great amps and Gibsons aren’t. It might be tempting to go further and conclude that only Fender Champs of whatever iteration can produce a compelling, warm, and textured sound because the Gibson sound is too clean. But—and this is where it gets interesting—these amps are incredibly similar from an electronics perspective. My Gibson 1956 GA-5 Les Paul Junior has three tubes: a 6SJ7, a 6V6, and a 5Y3 and not much else: a power transformer, an output transformer, a power switch, two input jacks, a volume control, seven capacitors, eight resistors—that’s it. A tweed Fender Champ FC-1 has three tubes: a 6SJ7, a 6V6, and a 5Y3, a power transformer, an output transformer, a power switch, two input jacks, a volume control, seven capacitors, and eight resistors. As far as I can tell (and admittedly, I’m no electrical engineer), they are the same amplifier!
What about that “clean” thing? First, a quick tube-amp review: When guitarists refer to a clean tone, they generally mean a tone free from obvious distortion. But, as Curtis Craig, a professor at Penn State and a sound media designer and composer, explained to me, a perfectly clean tone—a pure tone, one free of any harmonic overtones—would sound like a tuning fork or signal generator. It would have no color, no timbre, no characteristics of the plucked guitar string that produced it, and it would not be a fun listening experience.
What we call a clean sound from a guitar, even an unamplified one, actually consists of a fundamental frequency and four or five audible harmonic overtones. The signal is not pure, so it’s technically a distorted signal, but we perceive it as warm, not as distorted. A plucked A will have a fundamental frequency of 110 Hz and a second-order harmonic overtone of approximately 220 Hz. By way of contrast, a trumpet produces about 20 harmonic overtones, and an overdrive pedal produces several hundred harmonic overtones.
What makes tube amps so cool is what they do with these harmonic overtones. A solid-state amp might produce the same number of audible harmonic overtones as a tube amp, but the relative power of the higher order (above seven) harmonics will be different in the tube amp from what it is in the solid-state amp. Craig says, “This is where the ‘black magic’ comes in: People attribute a warmer sound to an amp when there is relatively more power in the lower order harmonics [two, four, six], or when there is lower power everywhere except the original signal [the fundamental].”