Vox AC50 Amplifiers, late 1964 and early, large box in serial number order

Vox AC50s from later 1964 and early 1965 in serial number order

Valve rectified, large box

This page gathers together, in order, known valve rectified AC50s from later 1964 and early 1965 with serial numbers in the range 1750-2200. No valve rectified Vox PA50s, which will have had numbers in this sequence, have so far come to light.

A principal defining characteristic is that serial number plates are part hand-stamped and part machine stamped:

"AC50" is hand stamped, the serial number itself is normally machine stamped.

The only exceptions so far, Vox being Vox, are numbers 1966, a large box amp, and 2088, which is, unusually, in a small box. Model and serial number are both hand stamped.

The amps encompassed on this page, as on the first overview page for AC50 Mark 2s, were all made under contract for Vox by Triumph Electronics. Triumph was based in Purley. For most of 1964, finished chassis were shipped in batches to the Vox Works at Dartford - 119 Dartford Road.

Boxes were then provided, the speaker and mains leads in the amp soldered to the sockets on the back-boards, and serial numbers assigned. Since the chassis were not stored in order of production, one regularly finds older ones with higher numbers than newer ones. They were boxed up simply as they came to hand from the shelves.

In 1965 amps will have been sent from Purley to the Vox / Burndept Works at Erith. The despatch department was on the top floor of the building.

Before the amplifiers were sent out, the serial numbers were noted in ledgers (now lost), along with the destination / name of the shop or person who had purchased or ordered, and type.

The driving force for production continued to be demand from America - the "Million Dollar" deal forged with Thomas Organ. In late 1964 production of the AC50 was also taken up at the Vox / Burndept Works in Erith. Details of amps assembled there are being collected together here.

Notes

Various elements are still variable: grille cloth is mainly black, but brown is found sporadically; old-style black escutcheon panels are found on the backboards of these too. Grey escutcheon panels are the norm, however.

Voltage selectors can be slot or domed rotary. The link selector is gone.

Plastic "black bat" mains switches made by Arrow supercede the metal switches of earlier amps.

Potentiometers with date codes "GL" and "HL" = July and August 1964 are found through to amps with serial numbers in the very early 2000s. By no. 2072, we have "JL" date codes = October '64.

Triumph employees often signed the underchassis of amps in pencil. DE = Dave Earp. RW = Roger White. Both Dave and Roger signed serial no. 1449, below.

Excluded from the register below are the majority of amps with unknown serial number, and those with fake serial number plates. Unknown serial numbers (early amps) are on this page.

SURVIVING AMPS

Continued from the page on large box AC50s produced in late 1964, serial numbers in the 1300s to 1750.

Serial number 1763 - currently in the UK

Mains transformer replaced and logo probably from its Foundation Bass cab. The preamp is more or less untouched. The 0.1uf mustard caps have the date code B/64 = second quarter of 1964. Voltage selector gone.

Serial number 1766 - currently in the USA?

Mains lead hard wired. Original XLR output sockets in place. Possibly a slot voltage selector, though hard to be absolutely sure from the small pictures from ebay.

Serial number 1768 - currently in Norway

On the serial number plate, the model hand-stamped, the number machine stamped. Note the slot voltage selector. The original Cannon XLR sockets are still in place. Thanks to Bjorn for the pictures.

Serial number 1775 (?) - currently in Canada

A highly-polished AC50. Hand-stamped serial number. A couple of ancillary speaker output jacks added on the escutcheon plate.

Serial number 1786 - currently in the UK

A replaced choke, but otherwise in excellent condition. Note that batches of AC50s, including this one, have rectangular silver mica signal caps, probably Lemcos (up by the tone controls). The two main filter caps in the preamp have the code "HUT" = 26th week of 1964 - June '64.

Serial number 1796 - currently in the UK

Voltage selector removed. The amp designation "AC50" is hand-stamped on the plate; the serial number itself machine-stamped.

Serial number 1800 - currently in the UK

Sold on ebay in late 2014. Accompanied by a solid state Foundation Bass cab. Hand stamped "AC50"; machine-stamped serial number.

Serial number 1815 - currently in the UK

Great condition. The preamp is entirely untouched. Original mains lead (hard-wired) still in place.

Serial number 1821 - currently in the UK

A second set of pictures showing the cab's first generation Celestion 18" speaker sprayed in its later 1964 colour - "poly grey" or silver. The earliest units produced for Vox were blue.

Serial number 1847 - currently in Japan

1/4 inch jack sockets instead of XLR connectors - apparently original. Note that an amp on the previous page (with a link voltage selector) has an output panel of the same sort (white circular surrounds for the jack sockets). Machine-stamped serial number. Images originally posted here.

Serial number 1852 - currently in Europe

Slot voltage selector. The serial number is machine stamped on the plate, but the designation "AC50" is hand stamped. Latest code visible on the mustard caps is B64 = second quarter of 1964. One of the pots (normal channel, treble) has the code "BL" = February 1964. One of the Hunts caps on the bias board has the code "HDT" = 28th week of 1964 = July '64. The main preamp filter cap on the left has "INT" = 37th week of 1964 = September '64. The one on the right has "?UT" - perhaps "IUT" = 36th week of '64.

Serial number 1855 - currently in the USA

Evidently in good condition.

Serial number 1876 - currently in the UK

One of the filter caps in the preamp has the code "HUT" = 26th week of 1964 = July '64.

Serial number 1881 - currently in Japan

Grille cloth renewed. Front baffle has a vent. White warning plaque; jack sockets now on the back panel escutcheon plate. Mains cable hard-wired.

NEW

Serial number 1889

Paired with a post-JMI Foundation Bass cabinet. Slot voltage selector. In the preamp, Hunts capacitors with date code "HNT" = 27th week 1964. The Mullard mustards have "A4N" and "C4N", first and third quarters of 1964 for their manufacture. Two of the original yellow-print Mullard preamp valves have paint code "LJ" = September 1964.

Serial number 1891 - currently in the USA

Grille cloth renewed. White warning plaque on the back panel; original rectangular Cannon speaker sockets still in place. At some point a hole was drilled in the back panel through the serial number plate.

NEW

Serial number 1904 - currently in Europe

Serial number 1915 - currently in the UK

Hand-stamped "AC50", machine-stamped serial number. By the 1970s a Vox factory reverb - the type designed primarily for AC30s - had been fitted to the amp, but unfortunately it had become unusable, producing noise even when off, so was removed. The controls remain. Thanks to Grant for the pictures and details.

Serial number 1925 - currently in the UK

Hand-stamped model designation, machine-stamped serial number. Thanks to Luke for the picture.

Serial number 1938 - currently in the UK

Formerly owned by Noel Gallagher, as the amp below. Sold on Reverb in late 2017. Original dome voltage selector in place (and the original Cannon XLR speaker connectors on the back panel).

Serial number 1946 - currently in the UK

Formerly owned by Noel Gallagher. Sold on Reverb in late 2017. Voltage selector removed. Note the early box - two cut-outs in the baffle behind the grille cloth.

Serial number 1958 - currently in the UK

On the serial number plate: model hand stamped, number machine stamped. Certainly valve rectified. One can see the valve bases through the slots in the baffle. On the back panel, note the grey plate for the speaker output sockets.

Serial number 1965 - currently in the USA

Visible date codes: pot "GL" = July 1964; Hunts cap "INT" (?) = 37th week of 1964; Mullard mustard capacitors "A4N" = first quarter of '64. The original Cannon XLR speaker sockets are still in place on the escutcheon plate.

Serial number 1966 - currently in the USA

In company with number 2088 further below, model number and serial number hand stamped on the serial number plate. Some obvious changes externally. No details of the electronics.

Serial number 1973 - currently in the USA

Model and serial number are hand stamped on the plate, a relatively late instance. The speaker cabinet seems to have been issued without a logo (no sign of glue on the cloth or drilling in the baffle. Thanks to Johnny for the pictures.

Serial number 1982 - currently in the UK

Serial number plate hand-stamped ("AC50") and machine stamped (serial number itself), New capacitors added in 1973 and probably the replacement mains transformer at that time too. The mustard capacitors have the date codes "B4" and "C4" = second and third quarter of 1964.

Serial number 1988 - currently in the USA

Excellent condition externally - the original Cannon XLR speaker sockets still in place on the back panel.

Serial number 1999 - currently in the USA

Paired with a US Vox cab (Berkeley).

Serial number 2020 - currently in the UK

Valve rectified, recently sold - a replaced handle, voltage selector removed, but otherwise in good order.

Serial number 2031 - currently in the UK

Late 1964. Note that V O X is in individual letters on the amp, as no. 1999 above, and no. 2069 below. The cab is late JMI, from 1967. Thanks to Dave for the pictures and info.

Serial number 2038 - currently in the UK

Grille cloth renewed early on; a replaced output transformer, otherwise in excellent order. Chassis signed off by Dave Earp ("DE"), who worked at Triumph in the mid 1960s. The main Hunts filter caps have date codes "HIT", "HNT" and "IIT", respectively 23rd, 27th and 33rd weeks of 1964. The smaller 25uF 100v ones don’t seem to have date codes on them.In the preamp, Mullard mustard capacitors with "A4N" and "B/64" date codes = first and second quarters of 1964 for their manufacture. Pots have date codes "AK", "GL" and "IL" = respectively January 1963; July and September 1964. Thanks to David for the pictures.

Serial number 2069 - currently in Australia

Brown grille cloth. Individual letters for the logo V O X. The underchassis is signed "DE" = Dave Earp who worked at Triumph in the mid 1960s. The transformers have paper stickers with their codes: mains is JMI M 007A; output is JMI D 008A; and choke is JMI X 009A. One of the Hunts 16+16uf filter capacitors has the date code "TIT" = 43rd week of 1964. Thanks to Glen Lambert for the pictures.

Serial number 2072 - currently in Italy

As above, individual letters for the logo; but black grille cloth. Replaced mains and probably output transformers. Pot codes are JL = October 1964. The same blue Hunts capacitors as in the amps above. Sold on ebay in mid 2012.

Serial number 2086 - currently in the UK

As serial number 2088, below, a late instance of a small box. The transition from small to large took a while to work through. In the preamp of number 2086, Mullard mustard capacitors with date codes "A4N", "B/64" and "C/64", respectively first, second, and third quarters of 1964. Mains and output transformers replaced with US-made units. The fittings on the back panel will originally have been the same as those of number 2088. Thanks to John for the pictures.

Serial number 2088 - currently in the UK

A standard grey panel twin channel Mark 2 chassis in a small box (from factory) - a late instance. Model and serial number both hand-stamped.

Serial number 2143 - currently in the UK

Serial number 2147 - currently in the UK

Single letters for the V O X logo as in the amp below. Distinctive Triumph transformers visible through the top grille. A new chassis in an older box.

Serial number 2164 - currently in Sweden

A few changed components here and there, but otherwise good. The amp belonged in the 1960s to the bass player of the Swedish band The Sleepstones. Thanks to Lenny for the pictures.

Serial number 2172 - currently in Europe

"AC50" still hand-stamped on the plate.

Serial number 2175 - currently in Scandinavia

Pictures from this page.

Serial number 2187 - currently in Europe

Changed at some point from valve rectified to solid state. The output transformer may be a factory replacement. In the preamp, Mullard mustard capacitors with date code "C4N" = third quarter of 1964. The panel for the speaker sockets on the back of the amp is black.

Serial number 21xx - currently in the USA?

Single letters - V O X - for the logo, as in the case of a number of amps on this page. Voltage selector unfortunately missing. Black escutcheon panel for the XLR outputs.

Reboxed

Now in box with serial number 3527 - currently in the USA

An early chassis with link voltage selector in a later box. Note the mis-aligned screw holes on the top edge of the back panel.

On to valve rectified AC50s made by Burndept, serial numbers in the 2000s.

Back to valve rectified AC50s serial numbers in the range 1300-1700.