Dating vox ac30 top boost
As rock raged through the late ’50s, though, a more powerful amp was needed.In late 1959, Denney and Jennings first tried using two more powerful EL34 tubes in a short-lived AC30, then simply doubled the AC15’s output stage to four EL84s to give birth to the amp we know and love today.Early AC30s sound great in their own right, but the model evolved to its optimum form when the Top Boost tone stage was adopted—first as a back-to-factory add on in 1961, then as a standard model option in 1964.The Top Boost circuit adds another preamp tube to the signal chain, as well as a simple yet powerful EQ stage with Treble and Bass controls that are very active and interactive in use, upping the chime factor and adding a little grind when pushed hard.The resulting amplifier was dubbed the AC30/4 Twin.Boasting 30 watts, two 12” Celestion speakers, four inputs, and two channels – Normal and Vibrato, the AC30/4 Twin was a hit amongst Rock ‘n’ Rollers in London, and quickly established VOX as the most desired amplifier in all of Britain.The AC30’s cathode biasing and lack of negative feedback give plenty of sparkling, slightly unchained chime to the guitar’s upper-mids and highs, thanks to the way they encourage second-order harmonics as artifacts of distortion.This offers a flattering tonality at low and middle volume levels, and a creamy, textured overdrive when cranked.
This song, and the frenzy that was to follow this young group in the months to come, would result in VOX becoming the most sought after guitar amplifier in the world.
From popular reissue to favorite boutique-amp inspiration to pride of place on every modeling amp’s selection menu, the mid- ’60s Vox AC30 with Top Boost is one of the most copied, emulated, and reproduced amp designs ever created.
Hell, if imitation is the sincerest form of flattery, the AC30 has been red-cheeked for decades.
Rather than design an entirely new amplifier from scratch, Denney decided to stick with what he knew was a winning design and doubled the power of his beloved AC15.
To accommodate the increased power of this amplifier, Denney saw it fit to expand the dimensions of the amplifier’s cabinet and add an additional speaker.