early prototype chassis found; Beatles connections part 1


A fabulous early chassis has been found, in Switzerland of all places, which raises all sorts of questions.  We’ve been trying for years to find out more about the Beatles amps, but it was impossible to get any information on the rumoured survivor.  This example now gives us a real insight into those amps.

Was this the style that the Beatles amps used?  Could it even be an actual Beatles amp?  We know guitars and gear were lent out and ‘went missing’ from various places.  Without any provenance though (this amp was just found in a basement), or any pics of the known surviving beatles amp, all we could do was to examine it as closely as we could, and see where it would take us.

The first thing that leapt out was the odd cut-out corners on the back; we hadn’t seen anything like this before. This didn’t necessarily mean it wasn’t a legit triumph/vox produced amp – but unlike other features, this seemed to be a one-off. These must have been awkward and time-consuming to produce; what was the point of all the time and effort?  The Beatles amps had a removable back panel.  Back in the VoxTalks days, it was presumed that this was so the chassis could be removed from the back for servicing..but the tops of screws were visible holding the panel on.  These obviously went into some kind of support – but these support struts at the back would have blocked the removal of the chassis. The chassis could never have been removed from the back then.  It seems the removable back panel was to make it easier to swap valves, and change the bias. This nice idea was dropped in production though; the single handle was swapped for two, to make it safer and easier to carry, and the whole thing was made wider and taller.  Probably this was for ventilation; they were already heavy units, with their big transformers. The transformers on this Swiss one were even bigger; with little ventilation in the cramped space (the prototypes were smaller, roughly 730-sized), they must have got very hot inside & on top.

It was great to finally see the slanting valve bases in detail; until now we’d only seen limited views of them, obscured by the rear panel. It was presumed before that the slanting bases were to help ventilate the amp; but now, with these ones at least, we can see that the slanting bases seem to be enclosed, so….little help with the ventilation there.  Again, it seems to have been to help with replacement of the tall kt88 valves – the Beatles units were less tall than the production run; they seem to have designed these to allow just enough space to swap out the big kt88s.
One of the most remarkable things though is those transformers; they are (even) bigger than normal.  They are the same height, but much deeper, with shorter ends.  This must have made them even heavier.  Mal was a powerful guy, but seems to have remarked on the weight of them to the driver, Alf Bicknell.  (see  – it-was-almost-50-years-ago-today-moving-the-beatles )   If the Beatles amps had transformers like these, it’s no wonder he complained – he can’t have been looking forward to having to carry these on the planned tours.

The cut-out corners (the overhanging metal cover over the valves has also been cut away) seemed to have been cut to fit around the support struts for holding the rear panel on the back.  There’s a problem though; there are only a handful of clear photos of the amps, especially the back – but one photo with Lennon at Abbey Road does show the lower corner of the rear panel.  The ‘problem’ is that the chassis doesn’t fit around the strut; it seems to just reach it, and then stop. Making and riveting cut-outs like these would seem then to have been a complete waste of time and effort, if the Beatles amps had been the same.  It’s hard to tell what was behind the corner though…  with a bunch of mostly very old photos of the backs of the Beatles amps enclosed in their boxes, it would be very hard to prove if there were any redundant cut-outs in the corner behind.  The same was true of the transformers; there are no photos of just the inner/under chassis.

If there were these redundant cut-outs on the Beatles amps,  the lower strut of the rear panel blocks the view of them.

Back of an early box, with the rear panel removed.  This box is larger & longer of course, so the MAINS switch is easier to get at here (the one in the Lennon pic is right by the edge), and this chassis doesn’t have slanting valves, or cut-out corners.  The cut-out in the new Swiss amp seem to suggest that the rear panel was originally planned to have been flush with the back.  You can see from the Lennon pic that the Beatles ones ended behind the strut anyway, like this one, so the cut-outs would have been redundant.  Note too the Bulgin power socket, sometimes used by Triumph.

It’s hard to discuss the possibility of something you can’t see though, so even though the front of this Swiss amp looks to be from the same template and maybe production run as the ones used on the actual Beatles amps, it was difficult to go much beyond that.  The front had the same characteristics we’ve discussed in other amps with proto fronts; different font for the labels or ‘legends’ making it look faint in photos, different placement of legends, smaller VOX logo, different design of diamonds.  It looks to have the same panel then, and the same slanting valve design, which is itself pretty remarkable.  Without an x-ray of the Beatles amps though or a photo of the insides, it seemed that it would be hard to go much further than that.  Or at least, that’s what we thought, at first.

To be continued…..



early prototype chassis found; Beatles connections part 1 | 2018 | Uncategorized