24th February (3)

Three more amps added: one with a serial number in the (closely similar to number 3385); and serial numbers and .

24th February (2)

"Vox Sound Equipment Limited" AC50 no. 1068 . Thanks to Timo for the pictures. Interesting that numbers of these amps went to Scandinavia.

Serial number 1068 is in Finland, its import probably handled by the PSO company = "Pohjoismainen Sähkö Oy". PSO was a major Vox dealer from 1967 to 1969 - on the Vox solid state website.

24th February

Melody Maker magazine, 20th August 1966

Melody Maker magazine (really a paper), 20th August 1966 - advert placed by Len Stiles - an AC50, probably secondhand, for £45.


11th February (2)

The entry for now updated. Thanks to Paul for the pictures:

Above, a detail from the preamp, showing blue Hunts caps with date code "YNS" = 7th week of 1965. See for further details. From the evidence assembling so far, it looks as though Triumph ordered batches every ten weeks or so, presumably ordering a new one well before its predecessor was too depleted. The batches appear to have contained caps produced in different weeks (as one might expect). Triumph will have known fairly early on how many AC50s could be and were being produced per week.

But one cannot entirely rule out the possibility that new supplies were ordered fairly randomly, on spec. - more admin, more bother, but nonetheless possible.

11th February

A nice diamond-input AC50 with basketweave tolex - a little while now on ebay.uk. For similar amps, . Around 250-300 of these were made in the Spring and Summer of 1964. Most were paired with Foundation Bass speaker cabinets; a proportion however were sold for guitar.

Above, Chuck Botfield of the Rocking Berries, pictured in "Beat Instrumental" magazine, no. 28, August 1965. The speaker cabinet is an AC30, as it is in the picture (though not in the description) of the "Royal Guardsman" in the US brochure below - count the number of diamonds across the front: 17 1/2.

The trolley above appears to have parallel bars across the top, so of a newer sort than the one depicted below.

22nd January

Thomas Organ advert, early 1965

A Thomas Organ brochure from early 1965 - the AC50 as "The Westminster" and "Royal Guardsman" prior to the transferring of the names to amps in the solid state line.

Note, however, that the AC50/Royal Guardsman as described in the blurb is actually a new large box amp (twin channel) with a large box cab (33" wide). The picture is simply an old one re-used.

Below an advert for the AC50 / Royal Guardsman in the Chicago Daily Herald, 26th August 1965 - reduced from $730.00 to $660.00.

Chicago Herald August 1965, advert for an AC50 / Royal Guardsman amplifier

Vox dealers in the US were still selling (or rather selling off) English-made valve amps in late 1966 - see this entry below.

The amp below (entry for 15th Jan.) looks to have been assembled to look like the one in the brochure above. Cab and amp are certainly original, but not to each other.

15th January (2)

Notes on date codes in the blue Hunts capacitors used in AC50s have now been gathered together Further details will be added.

15th January

Diamond input AC50 in thin edged box

Recently surfaced, a diamond input AC50 mark 1 in a thin-edged box. The trolley is repro and the cab an AC30. A similar amp survives in the UK.

Pictures of an amp, trolley and speaker cabinet set - serial number in the higher 3000s - .

14th January (3)


Above, an AC50 currently in Scandinavia, serial number probably in the 7000s: late 1966 or early 1967. Note the hang-tag, supplied by Vox, slipped into the voltage selector slot. Scandinavian legislation had long required selectors to be removed from imported electrical devices. Further pics of the amp, disassembled, .

14th January (2)

Above, pictures of an early AC50 mark 2 in a small box (from the factory), currently on Reverb.com. Also .

The mustard caps have date codes "B4" = second quarter of 1964. One of the Hunts capacitors has the code "HNT" = 27th week of '64 = early August '64. It is likely therefore that the amp was made in late August, possibly September, of that year.

14th January

Further amps newly registered: , , and . A further batch to follow soon.

13th January (5)

Pictures of serial no. 3435 (its serial number plate mis-stamped) .


Just to gather together some fairly well known points. The earliest cabs had baffles made from birch ply. Speakers were silver alnico T1088s. See for instance, the cabs accompanying serial numbers and .

By the time we get to AC50s with serial numbers in the 3000s, a different arrangement prevails. Baffles are made of chipboard (particle board), and Celestions have been set aside in favour of ceramic Fanes. See the many examples . For a very short period however, ceramic Celestion T1217s seem to have been adopted (or at least tried out) - see .

A small number of cabs accompanying amps with numbers in the 4000s, however, have unpainted ply baffles - see for instance.

At some point in 1966, corresponding with serial numbers in the lowish 6000s, ply baffles seem to have been reinstated as a matter of course. At much the same time, Goodmans 241 speakers were bought in - see the cab .

Survival rates for early large-box cabs are relatively low - in all likelihood a consequence of the inability of the alnico speakers to stand up to the power put out by the amps. When the speakers failed, one imagines many of the cabs were put aside.

13th January (4)

Vox AC50 supplied by Cumiskey and Sons, Dundalk

A Vox AC50 supplied by J. Cumiskey and Sons, Dundalk (County Louth, Ireland). The premises were at 42-43 Clanbrassil Str. - photo below. Never has such a large dealer/supplier plate been so prominently applied. The amp is a VSL model, c. 1975.

13th January (3)

Also repeated from the Vox AC100 website - The Arlington Heights Herald, 17th September 1964 - three weeks or so after JMI had agreed to provide 1.5 million dollar's worth of equipment (£534,000 then) to Thomas Organ. Note "just flown in". AC50s along with a certain number of AC80/100 will have been among the first batches to arrive. The Herald was presumably reporting the arrival at Chicago - see below.

Vox advertisement from The Chicago Tribune, 13th December 1964. The Thomas Organ Studios at the Golf Mill Shopping Center was about 2 miles away from O'Hare International Airport.

Above, a copy of a Thomas Organ service bulletin of December 1964, still circulated as part of the "Vox Amplifiers Service Manual, Volume 1" in 1967 - the subject "Blown Fuses". In the UK, AC50s and AC100s normally had 3A fuses, so no change for the AC50 in the USA.

13th January (2)

Repeated from the AC100 website - The Pittsburgh Post Gazette, 23rd August 1966 - Joseph Horne and Co. still offering English amps. The AC100 (Super Beatle) for $869.95 - note the mention of two inputs and "tone circuits for split effects" (not sure what that signifies). The AC50 (Royal Guardsman). AC50 Foundation Bass (Westminster). AC30 SRT (Buckingham Super reverb twin) - note the mention of three channels, six inputs, which might just as well indicate a solid state T. Organ amp, but more likely given the context, a slope sided AC30 SRT, its cab with a split front and closed back ("separate compression type speakers").

Early US brochures, flyers and adverts for Vox amps - including an early dealer pricelist and parts list - are being assembled on this page.

13th January

Three amps with added: 3051, 3541 and 3709. 3709 is the highest so far still with a white warning plaque. Red plaques have come in by no. 3814. On the boxes of AC100s, the red plaque appears around serial number 740.