The Vox T60 - development and history

The purpose of this page is to give an overview of the key points in the development of the Vox T60 amplifier, part of JMI's wider move into transistorisation. Quite when work began on the design of the amp, or rather its electronics, is unknown at present. Late 1961, early 1962? Perhaps much earlier. It is worth noting that by 1959 Jennings had already developed a transistorised assembly for its D2 "Entertainment" organ - see this page. That the T60 was well advanced by the summer '62 is clear at any rate.

First, a pre-production unit was offered to and accepted by Jet Harris - "star" endorsement - the amp forming the centrepiece of a couple of adverts placed in "Melody Maker" magazine in mid August. Jet is said ultimately to have used the speaker cabinet as a planter in his garden, not liking the sound one bit. More on that to come.

August 1962. The picture on the left was published in a music trade magazine, no side handles visible in the speaker cabinet; on the right, a detail from one of the adverts placed in "Melody Maker".

Second, at the end of the month a slightly more advanced version was exhibited at the "British Musical Instrument Industries" Trade Fair at the Russell Hotel in London. A page on the Fair can be found on the Vox AC100 website. Immediately below, a picture of the promotional amp and speaker cabinet at the hotel, along with the Transonic and the Jennings valve amplifiers available at the time.

August 1962.

Late August 1962, part of an advert placed by JMI in the music press to promote its display at the Trade Fair, the new transistorised equipment listed.

Below, a shot of an early - possibly pre-production Transonic - issued to the Laurie Jay combo in advance of their appearance on television. Jennings was extremely good at getting equipment equipment into the hands of bands that were due to appear on shows.

Laurie Jay combo, October 1962.

The next stepping stone is November 1962, a note in the music trade press to the effect that a new range of transistor amplifiers - the T60 a forerunner - was "well under way". It seems unlikely that very many T60s were ready for sale before 1963.

November 1962.

Early T60 speaker cabinets had two 15" speakers, 15 ohms apiece, wired in parallel for a total of 8 ohms. The nominal output of the T60 into 8 ohms was 30 watts. If two 8 ohm cabs were used, wired in parallel for a total of 4 ohms, then the power output of the amplifier doubled to 60 watts, not exactly a desirable thing. Early transistors often had flaws. Stress and undue heat could lead to "thermal runaway", ie. destruction.

The potential for using doubled-up cabs was nonetheless mentioned in adverts through to 1964:

Detail from a JMI brochure of late 1963.

The greatest boost to sales however - probably by a long shot - is likely to have been the setting up of Paul McCartney with a T60 and cabinet in March '63. The trolley seen in the matted picture below was used only once on stage so far as can be determined - at the Fairfield Hall, Croydon, in April.

JMI promotional brochure from 1963 with image of The Beatles, Paul with his T60 set, received from JMI in March '63.