"American amps are thick, British amps are raw." Talk guitar amps and you meet this rough scheme often. Fender is thick and sparkly; Marshall and Vox push the mids and break up rough.
But this isn't about national character or temperament. Thickness and rawness are an accumulation of the parts used, the circuits chosen, and the environment they were played in. This piece takes apart the design decisions that produced that "regionality," and reads the musical view implemented in it. A tendency is not a law — but a tendency has reasons.
Power tubes — 6L6 and EL34
The most symbolic thing is the choice of power tube.
American amps often used the 6L6 (and 6V6). The 6L6 has wide headroom, a firm low end, a thick, tenacious clean. Even saturated, it distorts relatively composed. Fender's big, roomy clean is inseparable from this tube's character.
British amps favored the EL34 (and EL84). The EL34 pushes the mids forward, breaks up earlier, and puts a distinctive grit and edge on the distortion. Marshall's "hit-you-in-the-mids" sound, and the chime and compression the EL84 gives the Vox AC30, come out precisely with this tube.
That said, "the EL34 pushes the mids" needs a caveat. This mid feel is less the tube's frequency response alone than an impression inseparably mixed with the circuit and speaker. How much is the tube's doing and where does received wisdom begin — I examined that split in detail in a separate article. Read this only as a "tendency."
Even within "tube power stages," this tube difference is one of the forks between thick and raw. And tubes were also chosen for availability and price. The EL34 was easy to make in Europe; the 6L6 was easy to get in America. The tendency of the sound is also rooted in the geography of industry and distribution.
Rectification — tube or diode
Another factor is the rectification method.
Some early American amps used tube rectification. Tube rectification produces "sag" — a momentary voltage droop when you dig in. The sound swells a touch late, giving compression and tenacity. That "lag" was one source of a thick, warm playing feel.
Choose the tighter, less-drooping diode rectification, and the attack is straight and the lows tight. Same tubes, and how the supply is built changes how the sound "draws time." Thick and raw aren't only about frequency — they're also the design of this temporal behavior.
Tone circuits and speakers
Tone-stack design split the regional sound too.
The so-called Fender-type tone circuit, common on the American side, tends to scoop the mids naturally. So the lows and highs stand out, giving that clear, sparkly, thick clean. The British side more often keeps the mids, so the sound pushes forward and has strong presence when it breaks up rough. A tone circuit is a choice of "which band to sacrifice," and the sound's character is engraved there.
Don't forget the speaker. In America, the sound of Jensen-type speakers that break up softly and early; in Britain, the sound of Celestion-type speakers with pushed, breaking mids — each decided the "character" at the final stage. As we saw before, the last color of a sound is set by the cab and speaker. Regional speaker culture is part of this scheme too.
Environment and music pulled the design
Behind the differences in parts and circuits is what music, at what volume, was ringing in that region.
American amps, raised amid wide halls, country, jazz, and early rock 'n' roll, were asked for a big, clean, thick foundation. Meanwhile, as British rock made a weapon of a loud, breaking sound, British amps didn't fear breakup — they polished rawness as character. Design isn't born in a vacuum. The music and environment being played pulled the choice of parts and the direction of the circuit.
So "America is thick, Britain is raw" isn't about temperament — it's the result of each region's intended musical view being implemented into an industrial product through the parts and circuits at hand. Thickness and rawness are characters made on purpose, not a ranking.
The label and the actual sound are separate
Here, one distinction is needed.
"British-style" and "American-style" are useful as an entry point when hunting a sound. But they're a rough map at best. American makers sometimes fit EL34s; British makers sometimes aim for a thick clean. High-gain amps from the '90s on have deliberately mixed both characters. A regional label only shows a tendency; it doesn't decide how a given amp actually rings.
When CSL explains a sound, it does use directional words like "British-style" or "American-style." But what it really keeps is the state of the sound one amp actually made under given conditions. Regional tendency is only a signpost, not a fixed sound. Which is why we record the state as it rang, conditions and all — not the label. Directional words and the actual recorded sound are handled separately.
In short
"America is thick, Britain is raw" isn't temperament — it's the accumulation of tubes (6L6 vs EL34), rectifier sag, tone-circuit scoop, speakers, and the music and environment they were played in. Each region's response to its intended music became the character of the sound, through the parts and circuits at hand.
And it's a tendency, not a law. Origin and brand are only labels showing a direction; the actual sound differs amp by amp. "British-ish," "American-ish" is useful as an entry point. But the sound past that door can only be checked one amp at a time — not by the label.