On Burndept Electronics, which shared a building with Vox off West Street in Erith, Kent, see this page.
The earliest Burndept-made AC50s have one set of white jack input sockets (normal channel) and one set of black (brilliant channel).
Serial number plates are fully machine-stamped - both the "AC50" and the serial number itself. The Burndept works was a far more orderly place than Triumph, and the sequence of numbers generally (always a qualification) goes hand in hand with the order of production.
Woden transformers and chokes are used instead of the unmarked silver-shrouded units that Triumph employed from the beginning of AC50 production.
Chassis have serial numbers stamped on the flat of the aluminium underneath the input jacks.
WIMA capacitors feature in the preamp instead of "mustards". Main filter caps on the upper chassis are often upright radial types rather than horizontal axial.
Dedicated mains sockets now figure on the back board. Previously the mains leads had been hard wired to the "ON" switch and fastened to the slider board with a clamp.
Below, a register of amps. If anyone knows of others that have not yet been included, do let me know.
Serial number 2269 - whereabouts unknown
Grille cloth replaced, and voltage selector removed. Arrow black plastic bat switch.
Serial number unknown - currently in the UK
The Woden output and mains transformers have the code JV = September 1964; the choke has HV = August '64. Pictures originally posted here.
Serial number 0236 (2036?) - currently in the USA
Burndept chassis number visible in the last picture. One of the white input socket nuts survives. Still holes in the chassis for upright filter capacitors, but the new style of axial clamps now in place. The transformers are Wodens, with unpainted shrouds - note the corner fixings. The code on the choke is "HV" = August 1964. The box is a North Coast Music replacement.
Serial number 2500 - currently in the USA
Thanks to Gene for the note on the existence of this amp
Serial number 2530 - currently in Europe?
Sold on ebay some time ago. A slightly split slider board, but otherwise in good condition. Voltage selector set to 225v.
Serial number 2532 - currently in Italy
Currently in Italy - link here. Valve rectified, two white input jacks, and a replaced logo, more in line with the date of the Dynamic Bass cab which accompanyies.
Serial number 2553 - currently in Europe
One of the white nuts from the normal channel input jacks has been moved to the brilliant channel.
Serial number 2555 - currently in the UK
Serial number 2559 - currently in the USA
A full rig in nice condition. Pictures from J. Elyea, Vox Amplifiers. The JMI Years (California, 2009), pp. 432-434. Preamp valve sockets replaced, tall feet added, and a new axial filter cap to replace one of the original upright units, but otherwise pretty much intact. The choke has the date code "JV" = September 1964.
Serial number 2562 - currently in the UK
Individual letters making up VOX. Original connectors on the back panel. The white jack plug rings have been swapped to the treble channel. Bias adjustment points have been added on the shelf.
Serial number 2609 - currently in the USA
Great condition. Only a few capacitors changed in the preamp. Woden transformers with the code "JV" = September 1964. Original Cannon mains connector still in place.
Serial number 2620 - currently in the USA
Sold on ebay US in 2011. Chassis number 0120. Code on the choke is "JV" = September 1964. The code on one of the pots is "IL" = September 1964.
Originally accompanied by a Foundation Bass cab in the same cloth. Perhaps a special order as the amp is almost otherwise unchanged.
Used by Hank and the Hankstirs in the studio.
Serial number unknown - currently in the UK
A beautiful looking amp, though pictured after an unfortunate bump. Images originally posted here.
Serial number unknown - whereabouts unknown
Sold on ebay in 2005.
Serial number 2644 - currently in the UK
Chassis number 0240. A replaced mains transformer, and a few other components here and there. The Woden output transformer and choke remain. Pot codes "KL" and "IL" = September and November '64.
Serial number unknown - currently in the USA.
Sold on ebay in September 2012. Burndept-made - note the Woden transformers. The choke has the code "JV" = September 1964.
Serial number 2952 (?) - currently in Spain
A high serial number for a valve rectified amp with white input sockets. Pictures originally posted here.
Serial number 3088 - currently in the USA
Sold recently (April 2017). In company with the amp below it, a straggler in terms of valve rectification. Triumph had gone steaming ahead with solid state rectified amps. Without any date codes, it's difficult to place this amp. But it seems likely that Burndept was simply using up available chassis as they came to hand.
Serial number 3226 - currently in the USA
Chassis no. 0272. Probably one of the last valve rectified AC50s to be made. The Woden logo is just visible on the mains transformer. Excellent condition.