In late 1962 / early 1963 Jennings set plans for a new model of amplifier in motion: the AC10 Super Twin Reverb. A circuit diagram - OS/026 - was drawn up, and in February 1963 the amp was advertised to the public, initially in "Melody Maker" magazine, then at trade shows and in catalogues.

The unusual thing was that Jennings decided to "mothball" OS/026, which embodied a circuit copied in large part from Ampeg's Reverberocket of 1961, and build the AC10 SRT as a standard AC10 chassis (and circuit) augmented with the reverb assembly that had been developed initially for the AC30 SRT (in early 1962). OS/026 was put to use some months later however - in the Domino Super Reverb. A year after that the circuit was at last used for its intended purpose - the AC10 SRT issued with a trapezoid cabinet for the amplifier section.

Various questions obviously arise: (1) why copy an Ampeg design?; (2) why was the circuit not used for the AC10 in 1963?; and (3) why the change of direction in late 1964? Answers to (1) and (3) are fairly self evident. The Ampeg circuit was evidently judged to be good (and presumably suitable); and in respect of (3), the Domino Super Reverb simply did not make money. The new AC10 SRT of late 1964, which had the same circuit as the Domino, was brought to market at over £30 more.

The new AC10 SRT was exhibited for the first time at the Russell Hotel Trade Fair in late August 1964. It is pictured at the show with a printed standee on top of the amplifier section.

But circling back, there is a further question, which should by right take precedence over the other three: how did JMI - or more specifically Dick Denney - come to know the Ampeg Reverberocket in the first place?:

Ampeg (and Denney)

In October 1962, the Laurie Jay Combo figured among the many endorsers of Jennings guitars and amplifiers - matching black Phantoms and a Vox Transonic ("AC30 Transonic") with integrated tremolo. The piece below embodies the earliest dated "real-world" (rather than studio or trade show) picture of the Transonic that has so far come to light. Jennings was surpassingly good at getting its equipment into the hands of bands featured in TV programmes.

October 1962.

By early 1963 however, Jay had evidently defected to Rose-Morris and Ampeg. The advert below is one of the first for Ampeg in the mainstream British music press.

January 1963. Pictured are a B15 bass amplifier and what appear to be two Reverberockets (sometimes called the "Reverb Rocket").

Although details of how the deal came to be struck remain to be clarified, it is clear that Rose-Morris had taken on distribution of Ampeg in the UK by the summer of 1962. A B15 and Reverberocket can be seen on the company's stand at the Russell Hotel Trade Fair in late August 1962

August 1962, Rose-Morris stand at the Russell Hotel Trade Fair, Ampeg B15 and Reverberocket centre foreground.

Dick Denney will, without a shadow of a doubt, have seen these amps. The Jennings stand - which he oversaw - was just a few along from Rose-Morris's. Quite what the specific steps were that led him to have the circuit of the Reverberocket drawn out as OS/026 in February 1963 are still anyone's guess. It does not seem unreasonable to think though that seed was sown at the Fair.

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