In August 1969 Tom Jennings expanded his range of small-format lightweight solid state amplifier sections with the official release of the 050 (for organ) and B50 (for bass). These joined the O100, B100, and PA100, which had been first in line. The page on the Jennings B100 can be found here.

Pictures taken at the Frankfurt Trade Fair in late February 1969 tend to indicate, however, that development of the two smaller amplifiers was largely complete by that point. It is difficult to tell for certain though. By mid 1969, the B50, B100, O50 and O100 all took the same form, the only distinguishing feature externally being the name of the model on the fascia, top right.

A detail of a picture taken at the Frankfurt Musikmesse, late February 1969, two new-style amplifiers right of centre. Resolution is not quite good enough to tell definitively whether these are the new O50 and B50, or simply new versions of the O100 and B100.

The range was in fact modular. The 100 watt amplifiers had identical power sections, as did the 50 watt amps. The only significant differences lay in the type of preamp provided: one for the two organ amplifiers; a second for the B50 and B100; and a third for the PA amps. For an overview of the JEI "O" and "B" series amps, see this page.

A brief preview of the Russell Hotel Trade Fair of August 1969 speaks of Jennings amplifiers with a "flat response". These were in fact the O50 and O100, described by Jennings in the catalogue of 1969 (extract at the head of this page) as having an "even response".

Detail from a preview report, printed July 1969.

Detail from the "Jennings News" newspaper-format catalogue produced to accompany the company's display at the Russell Hotel Trade Fair, late August, 1969. The page of the O50 can be found here.

The slight mis-wording in the report above, suggesting the amps with the "flat" response were something other than the organ amplifiers, was corrected in the preview of the Fair of August 1971:

Detail from a preview report, printed August 1971.

Prices

Prices in February 1970. Note the presence of a Jennings O100 designed for organ. The O100 was probably designed alongside the B100 and exhibited at the BMI fair in August 1969.

Prices in December 1972. Note that the B100 has come down in price by £100. The O100, which is on the other side of the page, is listed at £95.

As mentioned above (and on other pages), Tom's range of solid state amps was largely modular, the 0100's power section for instance being identical to the one used in the B100 and in the PA100. From an electronic standpoint, only the preamps were different.

The six amplifiers in the range - O50, O100, B50, B100, PA50 and PA100 - all had preamp output and power amp input sockets, providing an unusual degree of versatility for their relative positions in the market.

The power section of a PA100 (identical to the O100's) can be seen on this page. Details of the preamp of an O50 (again identical to the O100's) are here.

The 50 watt amplifiers had two loudspeaker sockets, the 100 watt amplifiers had four. Impedance selectors were not however provided.

Chassis are likely to have been assembled for JEI under contract by Triumph Electronics in Purley. Geoff Johnston, owner of Triumph, had done a good deal of work for Tom in JMI days. A little more is said - with illustrations - on this page.

In contrast to the bass amplifiers, no speaker cabinet was provided with or recommended for the O50 and O100. The buyer was left to make his or her own choice.

General views

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