This is a vintage 1965 Supro Thunderbolt model S 6420 electric bass guitar amplifier. This particular example is in well-preserved all original condition, and is in particularly fine cosmetic shape. Though originally intended for bass, the Thunderbolt has since become one of the most popular vintage guitar amps. Of the several variations of Valco-made Thunderbolt-style amps, the tube-rectified S 6420 is without a doubt the ultimate option. Additionally, this version is the rarest, with the solid state rectifier being a much more implemented approach in comparison. Great examples are somewhat hard to come by, and whether you’re having a problem finding studio magic or that missing piece of the puzzle that is your live rig, this would be a fantastic solution. Furthermore, of all the Thunderbolts we’ve listed, this is both the cleanest and best-sounding!
Serial Number: 1-34486
Transformer Codes: 5246517
Speaker Code: 220539 (Jensen C15PS, 1965)
The Thunderbolt Amp utilizes: (1) 5U4, (2) 6L6 and (2) 12AX7 original RCA tubes through an original 1 x 15″ Jensen C15 speaker. Yep, every last tube, all of which have ’65 date code stamps, is original to this amp, so the entire matching set is still intact and perfectly functional.
The grill cloth is in perfect structural condition, and the tolex is in correspondingly excellent shape. The chrome control panel is clean with some very typical surface oxidation, and the corresponding screened text is very nice. There is little oxidation on the hardware. The thin white stripe/band is very clean, intact, and nice. The original 15″ Jensen speaker is in excellent shape and sounds amazing. The cone is original, and it does not exhibit speaker fatigue nor voicecoil distortion.
This is easily the best-sounding Supro Thunderbolt we’ve advertised, and we have owned approximately 20. With better bass response, and an unbelievably rich overdrive, it sounds absolutely fantastic. Incredible with humbcuking pickups or standard single-coils, this is vintage tone at its best, and it is certain to become your new favorite amp.