Production at Triumph seems to have been pretty variable, with different ideas and directions being tried out. Roger White and David Earp worked on ac50s and ac100s in the mid-60s. Then, when work got slack, they were ‘lent out’ to Brooklands, the nearby company that made the faceplates (and later on circuit boards for solid-state models). As well as 7/4 series panels, Brooklands made panels for the vox domino & ac4. Edward Rook (Brooklands) had gone into screen printing; panels were sprayed, then fed by conveyor through a baking unit.
( Initials on ac50 chassis, Roger White, & probably his friend David Earp, click to enlarge )
Before moving to Brooklands, Roger and David worked on amps like the ac50 for supplying to Vox. Roger was there roughly from 1963-66; he remembers his first pay-slip as being for “.. 3 pounds, 17 shillings and sixpence, as it wasn’t a full week. I’d go through boxes of el34s, matching good push-pull pairs…I’d test them, making sure they got to 50 watts, the valves just glowing cherry red, before the sine wave started to flatten off on the scope. We used to stand the little ones up on their sides; they’d store a charge though, and we soon learnt not to pick them up by the transformer after some nasty shocks.
I remember the reverb units; ceramic cartridges with a bit of bent wire, coiled & soldered to the head of a brass OBA or 2BA bolt. There was total feedback on the first one, until they realised they needed to wind it in one direction towards the OBA/2BA, then in the opposite direction to the other end.
The assembly benches were below street level; there was a little light from a bit of glass-embedded pavement above, where you could just make out the shoes of people walking along. (infra-red heaters were suspended from the ceiling). I remember once Steve Rolfe was testing an ac4 or domino or something..he’d just stood up, when a capacitor exploded, leaving a black sooty mark on his white coat. Another time David Earp was leaning back on the rear legs of one of the tall chairs, while someone (Rolfe?) tested a 50-watt chassis on the bench..an electrolytic had been wired back to front or something and suddenly exploded; there was an almighty bang. Dave, in a great cloud of smoke, fell back on his chair, and banged his head on the floor. Afterwards he had to get a pair of tweezers and pull bits of metal foil from the cannister out of his arm.
chassis markings, probably early production
Triumph had a metal-working area for bending, drilling and punching the chassis, in the building on the other side of the piano shop. There was a massive fly press there..a heavy piece of kit, that could punch out the big holes for the transformers. You could hear the banging, even with the piano shop between us.
Me and Dave were asked one time to go out from Purley to a place in Coulsdon, on Station Apporoach road; Triumph wanted us to clean out an old shop, where they were going to produce or test the Beatles amp. I think they wanted somewhere where they could really wind the wick up”. (crank the amp up to high volume).