If there’s one amp that bears testament to the fact that what goes down on the concert stage is often much different than the alchemy brewed up behind the magician’s curtain of the recording studio, it’s the mid-’60s Model 24, made for Supro by the Valco company of Chicago. While the albums Led Zeppelin I & II had rockers around the world saving their pennies to purchase Marshall stacks and Les Pauls, Jimmy Page was laying down a hefty chunk of that fat, crunchy guitar tone with a Telecaster through a little 20-watt Supro Model 24 1x12 combo much like this one. Yeah, there’s been a lot of speculation over the years about which Supro he used, but most reliable accounts point to this model—or similar—being the most likely contender. But if you remain skeptical, you likely haven’t plugged into one of these before: Crank the volume beyond noon and lay into it, and this deceptively pretty blue box issues a guttural growl that remains punchy and tight however hard you hit it, with a thick, meaty overdrive that stands proud in the heaviest mix. The extra cool factor in all this is that the Supro 24 tone, while dynamic and exciting, won’t be mistaken for anything else. It’s not “a mini Marshall” or “a poor-man’s tweed Deluxe;” it is entirely its own beast, with a unique character that helps it grab the listener’s attention, all thanks in no small part to the fact that the Model 24 is put together like no other popular vintage amp of the era, other than a handful of other Valco creations.
This amp’s true glories take place on the inside, but before diving in let’s pause a moment to appreciate the exterior: the original Trinidad Blue vinyl is the stuff you really want to see on this model, and the silver pinstripe grille takes it all over the top. Add the silver control panel and it’s a sweet look for a deceptively fierce performer, but that’s part of the fun.
Remove the upper back panel and the chassis interior reveals the rat’s-nest wiring familiar to any player who has probed half a dozen B-list amps, with a boatload of round ceramicdisc tone capacitors where you’d normally see costlier, name-brand axial caps in Fender, Vox, or Marshall amps. But these circuits were plenty clever, too, and actually very well constructed for their price point. The preamp stages in the Model 24, with a Volume and Tone control for each of two channels, is different from any other popular circuit of the day, so add that to the component choices (budget grade, but characterful as a result) and you’re headed toward an amp with its own standout voice. Run all of that into the Model 24’s output stage and you’re brewing something utterly individual. With their tall, narrow glass envelopes and 9-pin bases the amp’s 6973 output tubes might look like EL84s at first glance, but they function very differently and contribute to a different-sounding amp as a result. These deceptively stout tubes are capable of taking much higher voltages than EL84s, and remain far firmer and punchier at higher volumes, too. They also succumb to less sag and compression than the more common EL84, and boast a thicker midrange and a somewhat darker tonality overall. Good new-old-stock 6973s are getting hard to find, which is one of the pitfalls of contemporary Model 24 ownership, but Electro-Harmonix makes a usable new replacement. Add Supro’s deep, swampy bias-modulated tremolo, and you’re in tone heaven.