Valco made a habit of reproducing the same amplifier circuit in different guises for competing companies. They pop up in National clothing, as well as Harmony, Gretsch and Airline garb.

Like so many now-classic guitar amplifiers, the Valco heads were designed as a bass amps, and instead have proven to be some of the great guitar amps of all time. Early in his career, Albert Lee played a Supro Thunderbolt, which inspired Jimmy Page to get a Supro. The consensus seems to be that Page also got a Thunderbolt, though some Pageholics say it was the smaller Coronado model. At any rate, it’s what he used on the entirety of the first Led Zeppelin album, paired with a Telecaster, which he also used on the “Stairway to Heaven” guitar solo and subsequent tracks. All I can say is a Tele paired with a Valco sure nails that sound. Ry Cooder also used to use one.

Though the Valcos' multi-branded variations went through several cosmetic changes and some minor component ones, there were basically two flavors to choose from: the early models which had a tube rectifier and a single tone knob; and the second designs of the mid-‘60s, which had separate bass and treble controls and a solid-state rectifier, which gives it more output and a tighter bass end. That's what this specimen is.

Somehow, with 2 12ax7s and 2 6L6s, some beefy transformers and not a hell of a lot else, Valco came up with one of the most responsive, throaty amps around, which when cranked lands somewhere between the articulation of a blackface Fender and the musical crunch of a plexi 50-watt Marshall, with your pick attack having a lot to do with which way it goes.

A few salient quotes from Mr. Page...

The Telecaster that Beck gave you, which you used on the first Led Zeppelin album, sounded more like a Les Paul.
“That’s the amp and everything. I could get a lot of tones out of the guitar, which you normally couldn’t. If you crank it up to the distortion point so you can sustain notes, it’s bound to sound like a Les Paul. I was using my Supro amp for the first album, and I still do. The “Stairway to Heaven” solo was done when I pulled out the Telecaster, plugged it into the Supro, and away it went.”

What kind of amplifiers were you using for session work?
“A small Supro, which I used until someone, I don't know who, smashed it up for me. I'm going to try to get another one. It's like a Harmony amp, I think, and all of the first album was done on that.”

Albert Lee told Vintage Guitar mag:
“You couldn’t walk into a British music store and buy a new American guitar at the time, because there were still import restrictions; they were lifted in ’60 or ’61. And when that happened, stores like Selmer’s, in the West End of London, got a tremendous range of Gibsons, and that’s where I bought my first amp, without even seeing it or trying it, but I took a chance because it was an American amp, and put a deposit on a Supro with a 15" Jensen. It turned out to be a really cool amp.”