JMI flyer (with pricelist on reverse) sent out in September/October 1961. The full page is here.

The "Super Twin" was first announced in broad brush to the music trade in July 1961:

Music trade magazine, July 1961. See also this page.

"Stereophonic" was in fact a reference to the "Top Boost" circuit (separate controls for treble and bass) fitted to Super Twin amplifier sections. That the Super Twin was the amp in view can be gauged from the mention of "pressurised" speaker units independent of the amplifier - in other words separate cabinets with closed backs - - see this page. The comment "Production at the moment is in hundreds, and thousands are being prepared for a large order received from abroad" is intriguing. Perhaps Germany? - though it may have simply have been a means of putting the competition off the scent.

By the end of September however, the name had become the one we know today - the "Supertwin" - and Tom took steps to register it in law, presenting an application for a Trade Mark to the Patent Office on the 25th:

Application on the 25th September; published on 23rd January 1963 (so that any counter-claim could be lodged); formally registered as belonging to JMI on the 19th of June.

It took the Patent Office around two years to register it formally - a relatively long, though not uncommon, span of time. Unfortunately most of the paper records relating to applications were destroyed in line with one of the more draconian Public Records Acts, so it is not possible to see or know why some moved more quickly than others.

The first general (public) announcement of the Super Twin came, however, in "Melody Maker" magazine, 28th October, 1961 - the "Super Twin de Luxe" at 125 guineas (£131 and 5 shillings):

"Melody Maker" magazine, 28th October, 1961 - detail from the Vox pricelist.

The Super Twin - "Super Twin de Luxe" - as advertised in "Melody Maker" was a two-part set: a separate amplifier section, and a closed-back ("pressurised") speaker cabinet with 2x12" Celestion blue drivers (T530) to help the speakers cope with bass frequencies.

By late October 1961 two types were available: the Super Twin I, with one speaker cabinet (125 guineas); and the Super Twin II, with two identical cabs (175 guineas).

As the JMI typescript flyer signals, the new AC30 had been issued first to Adam Faith and The Shadows to try out and "feature".

Early units were slightly different from later production models in at least one respect. Grille cloth covered the whole of the speaker cabinet front (a "valance" front), as one can see in the pictures below:

Adam Faith on stage, NME Poll Winners concert, April 1962, photo by Harry Hammond, his archive now in the V&A photo library.

Vox publicity photo (Reg Clark) published by Jim Elyea. Shane Fenton (later Alvin Stardust) with The Fentones. Note the full valance front AC30 Super Twin speaker cabinets. Note too that the amplifier sections have leather handles. The middle amplifier has its grille cloth "sideways" - the diamonds are horizontal rather than vertical.

Standard later Super Twins (in common with AC30 Twins) had a split front. Valance front Super Twin cabinets can still be seen, however, in JMI literature through to 1963.

The image above was first used in late 1961 and appeared regularly in promotional literature in 1962 (catalogue and flyers) and into 1963, one of the last occurences being the "Choice of the Stars" catalogue.

Initially amplifier sections had the new top boost circuit with controls (treble and bass) provided in a cut-out on the back panel. As has been noted, Jennings for a time termed the effect "stereophonic" - see this page. Later, top boost became an option rather than a standard fitting.

In May 1962, JMI advertised the new Super Reverb/Twin/I and Super Reverb/Twin/II. Controls were on the back panel in a cut-out; reverb pan and driver transformer mounted on the underside of the amplifier's slider board. Early examples are scarce.

The controls on the back panel of AC30 Super Reverb Twin serial number 2803.

The first Super Twins (Is, IIs and early SRTs) had serial numbers in the high 4000s, and they were numbered in sequence with plain AC30 Twins through to around serial number 10000. Thereafter Super Twins were given a sequence of their own beginning at 2500. One does find "stragglers" however, Super Twins into the 13000s still with numbers belonging to the standard Twin sequence.

Cabinets were covered in both beige and black pebble covering early on; handles were leather, one apiece for speaker cabinet and amplifier section. Beige gradually gave way to black. Injection moulded rubber handles came in around serial number 7000.

The pages on AC30s with serial numbers in the 5000s and 6000s, are here, and here.

If anyone knows of further early Super Twins that should be incorporated on this page, do let me know.

Serial number 4969 B - currently in Germany

An early AC30 Super Twin amplifier section. The "6" on the serial number plate is actually an upside down "9". Possibly the original black covering. Sold at some point by Freedmans of Leytonstone (London). The main Hunts filter cap in the preamp has the date code "HSW" = 25th week of 1961; the smaller blue bypass cap has "HWW" = 21st week of 1961. Note that amps covered in black occasionally had black plastic corner protectors. Amps covered in beige had none.

Serial number 5002 N - formerly in Italy, currently in the UK

An early Super Twin, grille cloth replaced, and probably an old recovering. Perhaps originally a Super Twin II. Note the twin speaker sockets (connectors made by Geloso). The speakers in the cabinet are from late December 1961. In the power section: the main Hunts filter cap. has the date code "HSW" = 25th week of 1961. The blue Hunts 32uf cap. underchassis has "WYW" = 10th week of 1961. AC30/6 schematics indicate a 8uf underchassis; but most amps have 32uf. The Welwyn 22K resistor has the date code "SE" = May 1961.

Serial number low 5000s - currently in the UK

Typical early elements: phantom cut-out in the chassis near the rectifier valve; Haddon transformers; rectangular Egen trimmer unit for the tremolo; box with square corners on the back panel; black WIMA Tropydur capacitors. The main Hunts preamp filter cap has the date code "YWW" = 1st week of 1961; one of the blue Hunts cathode bypass caps has either "WHW" or "WHH" = 12th week of 1961 or 1962, more likely the former. The amp still has its original Westrex inspectrion tag.

Serial number 5156 N - currently in the UK

Super Twin amplifier section serial number 5156N, probably early 1962. A replaced output transformer. The Hunts filter cap has the date code "HSY" = 25th week of 1960. In common with serial number 5002 above, the chassis has the phantom cut-out for the rectifier valve. Thanks to David for the picture and info. Further pics to follow.

Original serial number low 5000s - currently in Japan

Recently sold by "Howl Guitars" in Tokyo, an early Super Twin amplifier section, beige cloth, early 1962. The amplifier chassis, made by Westrex, has Haddon transformers, the earliest type of copper panel, white EL84 sockets, and the phantom cut-out for the rectifier valve. The serial number plate, with its three long panels and peculiar attempt at hand stamping, a later addition to this amp however.

Serial number 5204 N - formerly in Germany

Pictures from 2006. A Super Twin amplifier section with its original footswitch. Transformers are Haddons. No back panel Top Boost.

Serial number 5219

A Super Twin, original speakers probably still in place. Cabinet vinyl originally beige but painted black. Corner protectors added.

Serial number 5238 N - currently in the UK

An AC30 Super Twin amplifier section with Top Boost on the back panel. Thanks to Marc for the picture.

Serial number 5311 N - currently in the USA

A nice Super Twin with top boost on the back panel. Chassis assembled by Westrex. Transformers are Albions. In the preamp, there are several black WIMA Tropydur capacitors still in place. The blue Hunts capacitor in the second but last picture has the date code "YAH" = 9th week of 1962.

Serial number 5327 N - currently in the UK

Good and well used, with original footswitch. Probably from May/June 1962. Chassis assembled by Westrex; Albion transformers. The tone pot has the date code "DJ" = April 1962. The Celestion blues have cone code RIC 1 JC (possibly JL). Note the ribbed black PVC handle on the amplifier section (as serial number 5002). Serial number 5327 is also illustrated on this page. Thanks to Jim for the pictures.

Serial number 5329 N - currently in the USA

Older pictures of the set.

An early Super Twin with original cover for the amplifier section. Chassis assembled by Westrex. Transformers made by Albion: OT is part no. OH083/DT; mains is OH114/DT; and the choke PE241/DT. An add-on top boost circuit has been added (controls on the amp's back panel).

Serial number 5355 N - currently in the USA

A Super Twin head. Good to see some of the original black WIMA Tropydur capacitors still in place. The original footswitch is present too.

Serial number unknown - currently in the USA

A fantastic early twin, pictures just a little too small to make out the serial number. Some fabric has been added inside the speaker cab (to help reduce vibration).

Serial number 5367 N - currently in the USA

Serial number 5370 B - currently in the UK

Smooth black/charcoal vinyl. New handles and grille cloth on the amplifier section. The date codes on the Celestion blues are 01KH and 14KH = 1st and 14th September 1963, considerably later than the amplifier and probably the cab (assuming amp and cab go together). Note that the speakers have been out at some point and rotated by 90 degrees - normally the Vox logo is horizontal.

Serial number 5648 N - currently in the UK

Recently (September 2021) on ebay, AC30 Super Twin serial number 5648N, Top Boost on the back panel, beige vinyl painted black at some point. Chassis assembled by Burndept. Chassis number 1033. Woden transformers with date code "HT" = August 1962, one of the pots "GJ" = July '62. WIMA capacitors in the preamp. Ready for sale in late 1962. Speakers - one reconed in this instance - generally have later date codes than components in the chassis. Bought new in 1963.

Updated

Serial number 5676 N - currently in the UK

Black dimpled vinyl; a new-style handle to replace the original strap; and two later black vents. Electronics serviced in 2022 - mains and output transformers replaced, some other components renewed. The most striking thing is the vertical logo, as found on certainly early T60 speaker cabinets.

More recent pictures. Chassis number 01185, so assembled by Burndept, though all transformers now replaced. In the preamp one of the Hunts capacitors has the date code "HHH" = 22nd week of 1962. The tone pot apparently has "GJ" = July 1962.

Updated

Serial number 5854 - currently in the UK

A Super Twin, originally beige vinyl, now painted black. The inside face of the back panel is untouched. Grille cloth is new. Top boost controls added on the back panel, along with three later cut-outs, one for a plate with speaker and footswitch sockets, another for a Bulgin mains socket. The output transformer is a later, perhaps factory replacement, Woden date code "HV" = August 1964.

A post on FB (2022) indicates the Woden date code has now been cleaned off.

Serial number 58xx - currently in the UK

A good solid looking Super Twin, probably a Super Twin II originally (note the too factory-made holes for speaker connectors), some readjustment on the serial number plate though. Haddon transformers. In the preamp, WIMA red-print signal caps.

Serial number 5872 N - currently in the USA

The AC30 Super Twin amplifier section cabinet with this serial number on its plate now contains an AC30 chassis from 1964 (marked in red "T" for Treble).

Serial number unknown - currently in the USA

Serial number unknown - currently in the USA

Serial number unknown - currently in the USA

Serial number unknown - whereabouts unknown

Speaker cab missing its handle. The cabinet of the amplifier section has distinctive discolorations on its top.

Serial number unknown - currently in the USA

Note the plastic (rather than leather) handle.

Serial number 6056 B - currently in the UK

A Super Twin, the speaker cabinet now with later silver Celestion T1088 speakers (lacking VOX labels). Both cabinets are covered in the same heavy lightly patterned black vynide. The BASS flag on the amplifier section section is directly underneath the VOX logo, as on a number of other Super Twins from 1963.

Serial number 6313 - currently in the USA

Serial number 6716 - currently in the UK

A Super Twin amplifier set. Smooth black vinyl. Plastic corner protectors on the cabinets. Chassis assembled by Burndept. Note the new-style plastic handle on the amplifier section.

Serial number 6855 - currently in the UK

AC30 Super Twin amplifier section 6855 (Normal), paired with a slightly later Foundation Bass speaker cabinet (18" driver). The amp has been recovered, and regrilled to match the regrilled speaker cabinet. Thanks to Tessa for the pictures.

Serial number 6928 B - currently in the UK

Black dimpled vinyl, leather handles, speakers with April 1963 date codes. Thanks to Bill for the pic. and info.

Note

Serial number 7167 N - currently in the UK

A nice Super Twin amplifier section. Dimpled black vinyl. Factory top boost. Thanks to Sean for the pictures.

Serial number 7806 N - currently in the USA

Serial number 7086N. Note the new-style plastic handle = early 1963.

Serial number 7925 N - currently in the UK

The amplifier section of a Super Twin. Black "dimpled" or "pebble" vinyl. Chassis assembled by Westrex. Mains transformer replaced. The gold-coloured TCC bypass caps in the preamp have the date code "UC" = March 1963.

Serial number 8177 N - currently in the UK

Top Boost added on the back panel at factory. Pebble (dimpled) vinyl.

Serial number 8274 N - currently in the UK

Albion transformers, mains replaced.

Serial number 8311 B - currently in the USA

Albion transformers. One of the blue Hunts preamp valve bypass capacitors has the date code "HHH" = 22nd week 1962.

Serial number 8368 - currently in the USA

Serial number 8423 N - currently in the UK

Possibly originally a Super Twin II. Note the double speaker sockets on the back panel - now replaced with jacks.

Serial number 9394 N - currently in the USA

Basketweave vinyl. Both amp and cab have features which generally come in later - black vents and silver alnico speakers.

Serial number 9664 B - currently in the USA

Further pictures to come.

AC30 Super Twin, serial number 9664B.

Serial number 9677 B - currently in the UK

A Super Twin, Bass flag on the amplifier front. The Woden mains transformer has the date code "JU" = September 1963. The output transformer has "LU" = November 1963.

Serial number 9885 - currently in the UK

Further pictures to come. The Woden transformers have the date code "AV" = January 1964. Chassis assembled by Burndept.

Serial number 9952 - currently in the UK

Picture to follow

Serial number 9979 - currently in the UK

With an original set of covers. Top boost controls on the back panel of the amplifier section. The speaker cabinet appears to have been rewired.

Serial number 10472 N - currently in the UK

Still part of the main AC30 numerical sequence, a Super Twin.

Serial numbers unknown - 1963

NEW

Serial number unknown - currently in the UK

Chassis assembled by Westrex; Haddon transformers. The preamp is in good order: WIMA signal capacitors; TCC electrolytics, one with date code "UC" = March 1963, another (the main can) with "UE" = May 1963. The wooden case, covered in basketweave vinyl, has rounded corners to its backboards. The amp at one time had factory supplied Top Boost on the back panel (now removed). Thanks to Ian for the pictures.

On to the page on Super Twins, 1964.