13th September

A series of updates coming soon - around eight or so AC50s, late 1964 to late 1967 / early 1968.

2nd September

Images of AC50 serial number 1393 can now be seen The amp's cabinet was one of the first to be fitted a black escutcheon plate for the speaker connectors - two Cannon XLRs (replaced at some point with jacks for convenience).

1st September

Some pictures coming shortly of AC50 Mark 2 serial number 1393, thanks to Andy. The amp is an early large box AC50.

Model and Serial No. both hand stamped.

27th August

Just to signal for the time being that AC50 Mark 2 serial number 1873 exists. Thanks to Andy for the info and the picture.

Note that both "MODEL No." and "SERIAL No." are hand-stamped. From around serial number 1750, serial numbers were generally machine stamped, indicating that Triumph had started sending finished chassis to the Burndept / Vox Works in Erith, where there was a stamping machine.

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

Serial number 1873, probably in company with a few others (serial number 1966, for instance), was evidently sent out from 115 Dartford Road instead, where the only means of registering numbers was with hand stamps.

18th August

Carla Thomas on stage with The Mar-Keys, "Stax Volt Revue", April 1967 - an AC50 driving two Foundation Bass cabs. In another picture, an AC50 Super Twin can be seen on stage too.

The photo was taken by Jan Persson, a well-known Danish photographer; the venue Copenhagen - but the performance is not the one featured in the video that is claimed to be Copenhagen, 7th April, 1967.

Photo by Jan Persson from Getty Images.

9th August (2)

Some early pictures of AC50s in the USA taken at the two legs of the Vox "Battle of the Bands" competition (one of Marv Kaiser's promotional initiatives), late March to 16th April, 1965.

The two main venues were the San Mateo County Fairground and the Hollywood Palladium. The competition, part of the 4th Teen Age Fair, culminated at the Palladium on 16th April, the winner: Captain Beefheart. Further details can be found on the Vox AC100 website.


In view, a large-box AC50 Foundation Bass set; a large-box AC50 Super Twin speaker cabinet with a thick-edged small-box AC50 (?) on top - could just be an AC100; and a slope-sided AC30 SRT.


The Challengers, a popular surf band, on stage at the Palladium playing for TV between heats of the competition. One can see a large-box AC50 amplifier section in the foreground, and mid stage, an AC100. The speaker cabinets were elsewhere on stage.

Captain Beefheart, 16th April, 1965, Vox equipment all round - at least one AC50 Super Twin (without trolley) on stage. Picture from Vox Teen Beat magazine, no. 1.

9th August

Also posted on the Vox AC30 website (23rd July), an advert placed by the "House of Pianos and Organs" in the Miami Herald, 12th December, 1965.

The AC50 has its new American name: "The Royal Guardsman", assigned some months earlier. The drawing, representing a sort of idealised AC50 Super Twin of mid 1964, is highly anachronistic.

In late 1965, $750 was the equivalent of around £240. The JMI retail price list of November of that year has the AC50 Super Twin at £184.

Vox AC50 in the Miami Herald, 12th December, 1965
Vox AC50 in the JMI pricelist of November 1965

29th July

AC50 serial number 1768, valve rectified, late 1964 / early 1965. On the serial number plate, the model is hand-stamped, the serial number machine stamped. Now registered . Thanks to Bjorn for the pictures.

21st July

Immediately below, the end-page advert in the second edition of Shirley Douglas's, "Easy Guide to Rhythm and Blues for Bass-Guitar" (1963). Douglas was a long-time user of Vox equipment and both 1960s editions of her guide are well illustrated with pictures of fellow Vox users.

As can be seen, the advert is in effect an updated version of the ad. that appeared in "Beat Instrumental" magazine, August 1963, tailored, in the inclusion of the Phantom Bass rather than a Phantom Guitar, to Shirley. The interesting thing is that the price of the AC50 Foundation Bass set is given prospectively as 145 guineas (£152 5s 0d) - the amplifier was still in development at this point.

The only indications of actual price prior to mid 1964 come at present from a German flyer and the price tag that accompanied serial number 1101, an early four-input AC50 - pictured below.

In 1964 in Germany the AC50 Foundation Bass was DM2248, around £202 at the time, shipping and import taxes doubtless playing a part in the total. In England, its price was £165.

The pricelist of September 1964 probably gives the price - £173 0s 0d - of the new large-box amplifier.

Vox advert for the Foundation Bass cab, Beat Instrumental magazine, August 1963
Vox advert for the Foundation Bass cab, Beat Instrumental magazine, August 1963

Shirley Douglas, "Easy Guide to Rhythm and Blues for Bass", August 1963 - end page and detail.

Vox advert for the Foundation Bass cab, Beat Instrumental magazine, August 1963

"Beat Monthly" magazine, August 1963.

14th July

Player unknown at present, but a great Burns bass and small-box four-input AC50 with T60 (?) speaker cabinet. Photo probably from 1964. Large reproduction of a panel from the Bayeux Tapestry in the background, but with added text - a beer advert?

12th July

Pictures of serial number 7430, ready for sale in early 1967 and imported to Norway early on, . Thanks to Bjorn.

Detail of the preamp of serial number 7430.

6th July

Pictures of a valve-rectified large box AC50 from late 1964 or early 1965, the chassis assembled by Burndept Electronics for Vox. Note the white plastic jack plug nuts - typical of Burndept during this period.

The output transformer and choke are Wodens, date code "JV" = September 1964. The mains transformer is a replacement.

The amp was repaired / serviced in 1983 for the princely sum of £13 and something.

21st June

Some updates on their way.

Just a quick note on slider boards, following on from the entry for 6th November 2019, .

A number of boards, as below, have a sticker stating "Taylor-Made Woodware". Although such boards have so far turned up only in amps exported early on to the USA, the company that made tham must have been English - note the presence of "Regd", a form of copy protection, presumably for the trademark rather than the piece of wood.

One also finds the "Taylormade" stamp inside the wooden boxes of certain English-made radios, the example a little further below being the Ekco BPT333. Ekco (E.K. Cole Ltd) was based in Southsea.

Whether the "Taylor-made" boards came with the amps in which they survive, or, conversely, were supplied to Thomas by JMI as replacements for damaged or broken originals, is not known at present.

Slider board in serial number 3619

Detail from the picture of the Ekco BPT333 below.

11th June

Thanks to Bjorn, there are pictures now of , still the "old-style" rather than "American" logo. The date code on the red CCL capacitors in the preamp is "L6" = December 1967. The amp is therefore likely to have been made in early 1967.

4th June

Pictures of serial numbers 6106 and 6107 now registered . Thanks to Rob for 6106, which was evidently assembled by Triumph. 6107 was assembled in Erith by Burndept.

3rd June

Just to signal (no affiliation) AC50 Foundation Bass serial number 6010 currently on complete with its original covers.

22nd May

Below a detail from a feature - "Region Business in Pictorial Review" - in the Hammond Times (Northwest Indiana), 13th April, 1965: Hal Morris Music Mart in Lansing, Illinois, with an AC50 Foundation Bass, T60 set, and Continental organ.

Note on the back wall behind the necks of the guitars, Vox dealer photos (English bands), and to the right a copy of the Vox "Million Dollar Sound" catalogue.

The "Million Dollar Sound" catalogue, the reference being to the deal that JMI signed with Thomas Organ to supply $1million worth of equipment (around £534,000 at the time). The copy above came from Zeb Billings's Music Store in Milwaukee.

17th May (2)

Some quick shots of the Radiospares (RS Components) equivalent to the - the TH-1A Thermistor, produced from the late sixties through through to the early eighties.

The dot indicates that the piece had been checked. Thermistors and brimistors (simply a thermistor by another name) have no polarity.

17th May

A small batch of new amps now registered: an amp with a number probably in the ; ; ; .

Serial numbers 6281 and 6238 have identical supplementary red warning plaques in Swedish.

10th May

Some updates coming soon. In the meantime to signal the existence of AC50 Mark 2 serial number 1925. Thanks to Luke for the pic.

Hand-stamped model designation, machine-stamped serial number.

Below, pictures from an ancient ebay auction of a couple of Celestion T1088s from an early large box AC50 guitar speaker cabinet. The seller auctioned off the Midax horn and crossover capacitor separately.

Date code "17FJ" = 17th June 1964. So very early silvers in an early AC50 large box cab.

29th April

Four AC50 speaker cables: one from early 1964 (accompanying serial number 1034); one from late 1964 (serial number 1354); the other two accompanying an amp from 1966.

JMI must have bought in miles of this cable. It was of course not only used for AC50s but AC10 and AC30 Super Twins, and AC100s. Although the ridges and green-grey colour are distinctive, it is not known at present which company supplied it.

Original cables belonging to serial number 1034. Serial number 1015 also has its originals.

The two pictures above are of the cable from AC50 serial number 1354.

Cables from an AC50 from 1966, the XLRs at one end replaced early on with Radiospares jack plugs, either for two cabinets belonging to the solid state range (which were the only Vox cabs to have jack sockets), or perhaps two cabs made by another manufacturer.

24th April

Some details of a valve rectified AC50 assembled by for Vox in late 1964 (or perhaps very early 1965). Thanks to Pete for the pictures and info.

Transformers: Woden date codes "HV" and "JV" = August and September 1964.

Egen pot codes: Treble and Bass (1M linear) - part number 66520, date code "IL" = September 1964. Volume (500k log) - 66181, "JL" = September 1964. Bias pot (250k linear) - 66548, "JL" = Sept. '64

Hunts capacitors: date codes "INT" = 37th week of 1964; and "T HT" = 42nd week of 1964.