Thick-edged box; copper control panel; diamond inputs

Probably around 300-400 made


Single channel; link voltage connector; slots in the aluminium preamp chassis to allow the fixing of transformers of different heights; metal grille at top of back panel; in chassis plinth, 6 holes for each transformer, to allow those of centre as well as corner fixing.


Produced: Second and third quarters of 1964. Chassis manufactured for JMI by Triumph Electronics, Purley Road, Croydon.


No dedicated schematic for the diamond-input version of the AC50 survives (and perhaps none was produced). The circuit is that of the two-input amp.


At least two amps have linear pots for their treble and bass controls, instead of the logarithmic pots specified in schematic OS/044. As ever, the wiring of the controls varies - in some amps it appears to have been reversed: ie. the controls work "backwards".



SMOOTH GREY TOLEX

Serial number 1161

Sold on ebay late March 2013, further details to follow.


Above, new pictures of the amp. Thanks to Guy.


Another two images, one during the course of tidying up; the other with companion on small box cabs - wonderful stuff. Smooth grey tolex.





Serial number unknown - currently in the UK (?)

Sold on ebay in 2007. Immaculate condition, complete with original cover and leads. Single speaker output. Smooth grey tolex.





Serial number unknown - currently in the USA

Smooth grey tolex. A replacement back panel incorporated the original connectors, otherwise good condition. Large output transformer. Thanks to Steve for the pics.





Serial number unknown. Currently in the UK.

Smooth grey tolex. Cab and amp sold separately by Ampaholics in 2013. The cab is in the UK (further pics to follow). Note the non-standard position of the logo on the amp. Image original posted here.





Serial number unknown - currently in the UK

Used by the Brighton band "The Revivers". Replaced handle; on the back panel (just visible in the photo) two speaker outputs, and the original mains connector. The images were originally posted here. Thanks to Graham for permission to use on this site.






BASKETWEAVE TOLEX

Serial number unknown. Currently in Australia


Pot codes "BL" = February 1964. Further details to follow.





Serial number unknown. Currently in the UK (restored by ESE Music in Kent)

Pictures from March 2011. Excellent condition. A few replaced components, but all "mustard" capacitors still in place. White warning plaque centred on back.





No serial number plate. Currently in the UK

A fine amp with its original green cover still intact. A replaced handle, speaker socket, and a couple of new capacitors, but otherwise all original. Single letters for the V O X logo, and a Bulgin mains socket. Cannon LNE and XLR mains sockets seem to be a thing of slightly later amps. Thanks to Chris for the pictures.





Serial number unknown. Currently in Japan.

Grille cloth and logo possibly renewed? No image of the control panel available.





Serial number unknown - currently in Japan

A nice amp paired with a repro cab and stand. Unrelated to the amp above - note the wear on the top leading edge.





Serial number unknown. Currently in Australia.

A great amp that popped up recently in England. Thanks to Guy for the pictures.





Serial number unknown - currently in the USA

Pictures from 2007. No shots of the box. Holes for capacitor clamps are diagonal, as in the amp photographed on a black background, above. Note also the lack of underchassis mounting bracket for the mains transformer, again, as above. The volume pot has the code BL = February 1964 as in the case of at least one of the thin-edged box diamond input amps - see the foot of the previous page.





Serial number 118x (?) - currently in the USA?

Sold on ebay in 2006. Originals mains socket and single speaker output in place. White warning plaque centred on back. Logo composed of separate letters: V O X. Note that there is no point of fixing on the upper edge of the back panel.





Serial number 1217 - currently in the UK (collection: Mike Handley)

Logo composed of separate letters - V O X - as in the amp above. Also as above, four-pin Cannon mains input and three-pin output sockets. Warning plaque centred.


Images of the amp from ebay sale, August 2015.





Serial number 1220 - currently in the USA

Image from J. Elyea, Vox Amplifiers, p. 128. Note the logo, composed of separate letters V O X, as in the case of the amps above and below.





Serial number unknown - currently in Germany

A beautiful AC50 and early T60 cab - note the separate letters of the logo on the amp, and the "barred" O (a sort of theta) on the cab's logo. The amp is currently (August 2012) for sale - see this page. Thanks to Jorn.





Serial number unknown - currently in Japan

Just this picture - originally posted here. A beautiful set, both amp and cab with BASS logos.





Serial number unknown - currently in the USA

One of the few amps to have retained its "BASS" legend. Note the Cannon ITT-32 mains connector on the back panel. Warning plaque centred.





Serial number unknown - currently in Australia

A handsome AC50 in an AC100 box. The photos above show the amp in 2011. The pictures below show the present, restored state. Thanks to Guy for the images. The amp now has a new OT and circuit-correct capacitors. Note the distinctive shield underneath the input sockets. The treble and bass pots have the code "BL" = February 1964.


The volume pot has the code GM = July 1965, probably a factory replacement, along with the Wima coupling cap.





Serial number 1232 - currently in Australia

An AC50 in excellent condition. The volume pot has the code "DL" = April 1964; treble and bass pots "BL" = February 1964. One piece VOX logo. The third but last picture shows the amp in its restored state. Thanks to Guy for the new images.





Serial number 1244 - currently in the UK


No pictures, but discussed on an old Vox Talks thread - click here for a copy. Copper panel, diamond inputs, grille cloth replaced, signs of a previous replacement handle, renewed corner protectors. Amp serviced by Eric Snowball of ESE Music, who replaced the Bulgin connector with a modern IE receptable. ES also serviced the amp near the top of this page.





Serial number unknown - currently in the USA

Another nice amp belonging to North Coast Music. For further images, see the Vox Showroom site.





Serial number unknown - currently in Europe

Good condition. Original connectors - mains and single output - on backboard. White warning plaque centred. Thanks to Julien for the images.





Serial number 1312 - currently in Australia

Sold on ebay in 2014. A really nice AC50, apparently untouched electronically. Small output transformer.





Serial number 1326 - whereabouts unknown

Sold on ebay in 2006. Complete with its original maroon (?) cover. Double speaker outputs. White warning plaque off to side.





Serial number 1387 - whereabouts unknown

Reported by J. Elyea.





BLACK GRILLE CLOTH


The amps below are probably the last of the diamond input units, produced in parallel at Triumph with the new twin channel AC50s (both small and large box). For early large box AC50s in brown grille cloth, see this page.



Serial number 1532 - currently in the UK

Sold on ebay in 2006 (seller in Falkirk, Scotland). Amp and cab are in full working order. The latter is designated LFA52, serial number 11296. Thanks to Laurence for the info.


Wonderful original condition is evident from the pictures. The speaker cab is probably a very early solid state Foundation Bass cab - the driver is a Celestion T1296 (first logged in the Celestion record book in October 1966), there is a port underneath, and the baffle screws have been sealed with yellow paint (a typically later practice). The logo however is still of the old style, so this is probably a transitional unit between the valve and solid state lines.






Serial number unknown - currently in France

A splendid amp and cab set possibly with original black cloth. Currently on offer here.






Serial number unknown - currently in the USA


Sold on ebay in 2005. Probably the original black grille cloth, tired and sagging. Two sets of pics, the second showing the amp restored to full working order, and converted to two inputs by the provision of a repro control panel (the two other holes for input jacks blanked off by it). Thanks to Glen for info on this amp.