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Supro S6651

Supro S6651 Big Star
 
Ca. 1966 Supro S6651 Big Star

Ca. 1966 Supro S6651 Big Star. Photo and amp courtesy of Brad Klukow.

Don’t we guitarists just love gear that looks like it was salvaged from our mom’s kitchen circa 1961? Give us something in high-gloss pastel, with Formica styling, gas-cooker knobs, plenty of chrome, and an emblem lifted off a fridge door and we go weak in the knees every time.

When it comes to kitchen kitsch, this mid-’60s Supro model S6651 Big Star amplifier is hard to beat. What better color for a groovin’ control panel than turquoise (unless maybe it’s Surf Green)? And those chrome-centered knobs are plenty big enough to grope mid-gig with a modicum of accuracy!

And being a Valco product, it naturally sounds great. No, it sounds nothing like the “poor man’s Twin Reverb” that plenty of used examples have been sold as over the years, and has little of the pristine, shimmering jangle and twang of the big, clean Fenders of the day. Instead, the Big Star has a warm, thick, slightly gnarly tone that distinguishes many of this defunct Chicago amp maker’s products. Any time a ’60s Valco-made amp raises its head these days, the sepulchral image of Jimmy Page recording early Led Zeppelin classics seems to drift up and envelop the room, but this is unlikely to have been a piece of Page gear (he’s more likely to have used a model with 6973 output tubes, or something in a 1×12” at least). But if star associations are required, it can be said that Eric Clapton dabbled with this or a similar Supro in the studio (possibly the reverb-less Galaxy), and Joe Perry has also been seen fondling the turquoise. Although this was built to be one of Valco’s larger amps in the day – being 2×12” with a pair of 6L6GCs in the output stage – it really isn’t up to much more than club gigs or studio work, without mic’ing through a good PA system, at least. It is louder and just plain bigger sounding than the average Valco out there, but isn’t primed for the most efficient use of its firepower. And for the tone-hungry among us, we’d consider that a good thing.

Working from the output forward, consider that the Big Star’s 6L6s are cathode biased with no negative feedback, a configuration that hadn’t been seen in a 6L6-based Fender amp, for example, for more than 10 years, since the 5E5 Pro of 1955. Given the relatively low voltages that these big bottles dined on, too, around 370 volts DC at the plates and 320 volts DC on the grids, and the rather lean output transformers that Valco is largely known for, we’re only going to see about 30 watts at best, running downhill on a freshly waxed board! What this setup loses in volume, though, it makes up for in brown, gritty sonic goodness and pliant, tactile feel. It isn’t overly spongy, given the solidstate rectification, but certainly offers a compressed edge to the attack when you roll up the Volume and hit it hard. The amp’s original Jensen C12N speakers acquitted themselves well as in regard to crispness and sparkle, too, though overall the Big Star is still no twang machine.

Supro LogoThe preamp stages in each of the two independent channels, though outwardly fairly simple, pack plenty of Valco-style quirkiness. The Standard Channel is nothing unusual, though it still exhibits this maker’s propensity to do things its own way, but the Reverb-Tremolo Channel is masterfully odd. The unsuspecting Volume control hides a dual-ganged potentiometer that simultaneously controls the first gain stage (after the first triode in that channel’s own 12AX7) and the output from a second gain stage that follows the reverb circuit and Tone control. Later examples used a 12AX7 to drive the reverb, but this one uses a 6973 output tube. Its reverb is arguably a bit fuller as a result, although none of these have a delay sound to write home about. The Tremolo, however, so often a stand-out feature of these Valco-made amps, is a real treat, and runs from soft pulse to throbbing groove.

The circuits between the amps that Valco made for the many different brands it supplied were usually very similar, but the amps distinguished themselves by their looks, and models sold as Gretsch, National, and Supro always had individual styling that made each special. All looked pretty damn cool, with more out-and-out panache than many of the major-brands exhibited at the time, we might argue, but this Supro Big Star is certainly one of the sweetest (the original silver grillecloth on our well-gigged example appears to have been replaced with Fender-style grillecloth, but no matter). Players and collectors tend to fawn over the early-’60s Supros rather more, partly thanks to any supposed associations with Jimmy Page, and partly just because… well, if vintage is cool, more vintage is generally assumed to be cooler. But these later Valco-made amps packed many of the same characteristics, and offered much of the same tonal responses of earlier models with similar tube complements. Plenty might think they’d prefer an earlier tube-rectified model, too, but “solidstate” in the case of this Big Star’s diode bridge shouldn’t be considered any kind of sonic second-rate. A little extra firmness in an amp like this is often a good thing, and you’ll get all the dirty sag you need when you crank it up.

Amid all the hype over the Thunderbolt or the model 1624 of a few years earlier, pause to consider the younger siblings like the Big Star and the Galaxy – potentially great values in vintage Supros, and truly fun examples of tube amps made just a few years before this great Chicago manufacturer’s sad demise.

Circa 1966 Supro S6651 Big Star

Preamp tubes: four 12AX7, one 6973 reverb driver.

Output tubes: four 6L6GC.

Rectifier: solidstate

Controls: Volume and Tone on each of two channels, Reverb, Tremolo Intensity and Tremolo Speed on Reverb-Tremolo Channel.

Speakers: two Jensen C12N ceramic speakers.

Output: approximately 30 watts RMS.


Dave Hunter is an American musician and journalist who has worked in both Britain and the U.S. He’s a former editor of The Guitar Magazine (UK).


This article originally appeared in VG February 2010 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.

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