1964 Selmer Zodiac Croc skin Twin Fifty 2x12 Truvoice 2x12 50w
For a period of time at the very heart of the British guitar boom of the late 50's and early 60's, Selmer was the leader in the field of Amp builders, though it’s all too easy to forget. Briefly ahead of Vox, certainly ahead of the fledgling Marshall, this was a company that had it all to lose as the new decade dawned. And they gradually did...
By the mid 60's Selmer was struggling for position against a pair of strong rivals with growing international reputations, while releasing what would be its most recognized and most collectible models – the short-lived crock-skin combos of 1963 to ’65.
The most popular of these, the Zodiac Twin 30 and Zodiac Twin 50, were most likely released in direct response to the Vox AC30 and Marshall Model 1962 (a.k.a. “Bluesbreaker”) respectively. Good efforts they were, too. But while they made some waves at the time, they ultimately failed to blow either rival out of the water and did little across the pond. In the wake of this “defeat,” Selmer amps, though still great by any standard, slid into B-list status and started down the slippery road toward demise.
Regardless, models of all eras have continued to appeal to players and collectors for six decades, but fans are likely to drool most profusely over the combos like this 1964 Zodiac Twin 50. More often seen is the Zodiac 30, a combo based around a pair of cathode-biased EL34's, nominally what we refer to as “class A,” as famously used by Jack White to record the White Stripe’s Elephant album.
Obviously these mid-’60s Zodiacs looked very different from anything before, or after, too. Their blend of mock-crocodile and black vinyl covering gave them an extremely outré look, further accentuated by the spacey green “magic eye” tremolo speed indicator on the front, which pulsed in time to the trem rate. Even if the large gold metal Selmer badge on the bottom panel tied the amp to ubiquitous and less-than-hip trombone-case cosmetics, these were pretty outrageous packages, in an age and industry that was ramping up for plenty of outrage.
Pre- and power amp are built on separate chassis, mounted in the top and bottom of the 2×12 cab. Each of the 2 channels opens the gambit with a single ECC83/12AX7 gain stage, without any cathode bypass cap, which keeps the tone a little tighter and lighter at this point, but the two differ considerably from there.
Channel 1, intended for a mic or a second instrument, runs through a treble-bleed tone control that’s a little more involved than the average, then a volume control, then through a second gain stage comprising an EF86 pentode preamp tube, before scooting on to the octal plug that takes it south to the PI and the output stage.
Channel 2 though is where things really get wild. After the first gain stage, the signal hits a six-pushbutton tone section that offers a Rotary Control option, High Treble, Treble, Medium, Bass and Contra Bass. These are achieved by tapping a network of tone caps that shape the voice between gain stages, a circuit not unlike that of some large Gibson amps before it, or indeed the six-position rotary Tone control on the lead channel of the Matchless DC30 several decades later. From here, the signal hits another EF86 pentode, then a tremolo circuit with Speed and Depth controls, then on to the bottom chassis via the octal plug.
In the bottom chassis, the octal plug ferried the signal to a rather unusual split-phase inverter that employed another ECC83, then on to a pair of EL34's that were pushing around 445 volts DC at the plates – not a ton for these output tubes to handle, but pretty hot for the cathode-biased Zodiac Twin 30!
As cool as these amps are and as much as you might want one, their prices have escalated significantly over the past decade to the point they rival vintage AC30's. A difficult situation for the would-be buyer of a nifty Zodiac Twin 30 or 50, but it brings some measure of justice to round out the history of these exquisite and unique “also-rans.”