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Vox AC30 website updates

June 2025

28th June

Thanks to Helen, new images of AC30 Super Twin serial number 6328N, probably ready for sale in the first weeks of 1963. The latest component date codes currently known are of November 1962.

A new page for pictures of the amp will be created in the next few days. The main page on early Super Twins is here. AC30s with serial numbers in the 6000s (Twins and Super Twins) are here.

AC30 Super Twin serial number 6328N.

27th June

The four different types of speakers in AC15s produced in late 1960 and 1961: the Celestion CT3757; hammertone T530 (pre-blue); Goodmans Audiom 60; and Celestion blue T530.

The Goodmans Audioms appear for a short time only - amps with serial numbers in the mid 4200s: 4230N (split front); 4254N and 4261N (TV Front, two-tone covering).

The CT3757s and hammertone T530s seem to have been fairly old when fitted - i.e. they had been in stock for some time, a case in point perhaps being serial number 4229, its CT3757 dated September 1960.

Speaker from AC15 serial number 4229, "20JE" = 20th September, 1960.

Some care is needed, however. The chassis of serial number 4229 looks suspiciously similar to that of serial number 4270, sold on ebay some years earlier.

So-called serial number 4229. Note the black smudges on the green TCC cap and the series of capacitors to its left on the board.

Serial number 4270, cabinet painted black at some point in its past and chipped in various places. Compare its preamp with the pic above.

Serial number 4270, some of the more incongruous capacitors since changed, but note the wiggly wires leading to the speaker terminal block. New holes have been made in the aluminium lip to match those of the box of so-called serial number 4229.

Two cabinets, one AC15 chassis. Which box does the speaker belong to? To judge from four sets of pictures of these amps, serial number 4270 [ 1st July: not 4229 as noted previously].

The Celestion B024 in serial number 4177 is likely to be a later addition. The wiring is not original.

26th June

To add to the pages on third circuit AC15s from mid 1960 to mid 1962, a short list of amps, by serial number, with original Celestion blues (T530) of known date:

4318: 15th June 1961.

4438: 18th July 1961.

4482: June/July 1961.

4567: 19th March 1962.

4633: May/June 1962.

So far as one can tell amps from 4318 into the low 4400s sometimes had Celestion CT3757s rather than T530s. The latter are likely to have been reserved (used in the first instance) for AC30s.

What look to be the original blues survive also in numbers 4452, 4489, 4510, and 4543, dates unknown at present. In company with single-speaker AC15s, a certain number of Twins were fitted with blues too. Fan-frame Goodmans Alcomax (NOT Economax) drivers were not the invariable choice.

The page on RIC cones, used by Celestion into 1963, has now been updated and tidied up.

25th June

A correction to the entry for the 23rd: the first tap on the AC15 mains transformer pictured is 105v, not 115v. The page on third circuit AC15s has now been updated, the section on speakers slightly rearranged, some of the material posted below slipped in at relevant junctures. More to come on speakers shortly.

At present, the earliest AC15 known (verifiably) to have a Celestion blue is serial number 4318 - gasket dated "15FF" = 15th June 1961.

AC15 serial number 4318.

24th June

Two types of third circuit AC15 chassis. The first (earliest) type has a relatively narrow lip below the front edge of the control panel, around 1/4" deep. 550 or so of these chassis were made, serial numbers in the low 4000s to mid 4500s, black and early copper control panels, early/mid 1960 into early 1962.

Black panel AC15 from later 1961, chassis assembled by Westrex.

The second type of chassis has a larger lip, around 3/4" deep, with cut-outs for cage nuts (for the back panel fixing screws) inset. Serial numbers in the mid 4500s to the end of the run.

Copper panel AC15 from 1963, chassis also assembled by Westrex.

The change from narrow to wider chassis lip took place a little earlier where AC30/6s are concerned - mid 1961, noted on this page. AC30/4s had a narrow lip through to end of production (late 1961).

23rd June

The Haddon mains transformer of Rod's AC15 - part number "OF 031", taps provided for 105v (green); 145v (unconnected); 160v (yellow); 205v (brown); and 245v (blue). The presence of a tap for 145v is puzzling. Which country or place had this supply voltage? The question was asked here too of other equipment.

[25th June - the first tap is 105v, not 115v as originally stated.]

At the voltage selector on the control panel, the choices are: 110v, 160v, 205v, 225v, and 245v, clearly out of step with the transformer. JMI's solution? - to link both the 225v and 245v settings on the selector to the 245v tap on the transformer. A slight reduction in power for Europe.

22nd June (2)

Thanks to Giovanni, a couple of shots of one of the latest Vox Reverb units currently known, late 1966 or early 1967, "VOX" logo at left (normally at right on later units) and a "REVERB" runner on the grille cloth.

A new page on these Reverb units is coming soon.

22nd June

A quick overview of the dated components in the AC15 chassis pictured further down this page:

EGEN POTENTIOMETERS: channel I volume - "CI" = March 1961; tone pot - "HI" = August 1961.

HUNTS ELECTROLYTIC CAPACITORS: "HIY", "TYY", "TIY", "SWY", "YHW", and "WWW" = in order, 23rd, 40th, 43rd, and 51st weeks of 1960; 2nd and 11th weeks of 1961.

WIMA TROPYDUR CAPACITORS: "70", "80", and "110" = July, August, and November 1960 (manufactured in Germany).

WIREWOUND RESISTORS: "5905" = May 1959.

VALVES: ECC83 - "B0K" = November 1960; EZ81 - "B1F" = June 1961; and ECC82 - "B1H2" = 2nd week of August 1961. The Mullard EF86, print rubbed and faded, has "J4", which may mean "B1J4" = 4th week of October 1961. "J4" cannot be part of the date code system used by the company in 1960.

21st June

A detail of the tone pot of the AC15 chassis pictured below on the 18th - date code "HI" = August 1961, the latest component date code currently visible. The Celestion blue, unfortunately now gone, will have been later still though (speakers consistently have later date codes than the electronic components used on chassis). A full list of the other component date codes to follow. The amp as it originally stood is unlikely to have been ready for sale before late 1961.

Tone pot, date code "HI".

20th June

A better image of "The Sons of the Piltdown Men" with their early Vox Continental. The volume pedal is one of the chrome Fender pedals that Jennings rebadged as "VOX" - in all likelihood without permission.

Picture printed in September 1963. Does the organ body have a third hinge for the outer lid above the point where the leg braces meet?

19th June

A quick shot of the label from the output transformer of the AC15 pictured below. Other examples can be seen on this page.

Haddon part number OA 063.

18th June

Thanks to Rod, some pictures and details coming of a long unused AC15 chassis from the second half of 1961, a serial number probably somewhere in the 4400s. The speaker was originally a Celestion blue. Very few components were replaced over the years.

17th June

AC30 Twins with serial numbers in the 18000s and 19000s now have their own pages. The entries for 18513T, 18661T, 18715, and 18747TB have been updated. 18744TB (thanks to Giovanni), 18819TB, and 18908T are new.

16th June

A small pic - for the moment - of the "The Sons of the Piltdown Men" with an early Vox Continental organ (September 1963 or before) has been added to this page. The supports for the music stand are just visible on the lid. A larger image will be available soon.

15th June

New material relating to EKO, E.M.E., and Recanati, will now be set out on this page. It should be possible in due course to add a section on Earle C. Wolfe, lead member of the Thomas team at the factory. Wolfe oversaw for Thomas production of both organs and guitars, sometimes inspecting (and signing off) equipment at shop floor level.

In many respects, Recanati was a Thomas and EKO operation. Jennings seems to have been involved mainly at key junctures.

14th June

Picking up from yesterday's entry, one of the principal questions arising is that of how EKO came to be chosen in late 1965 to make certain lines of Vox (Jennings) guitars and organs? - the "why" of course being the need to ramp up supply for Thomas in the USA.

The answer may lie in EKO's presence at the NAMM show in Chicago in early July 1965. Jennings, there with Thomas's "Vox Division", received a huge order from Thomas for new equipment at the show. Commenting on the order a few weeks later in the British music trade press, Tom signalled the impending need to increase production. Had Oliviero Pigini and Ennio Uncini outlined EKO's forthcoming plans for expansion to Tom and Joe Benaron in Chicago? Was EKO the obvious choice?

Remo Serrangeli, who published a fascinating account of the making of Vox guitars at Recanati from 1966-1968, seems to indicate that Thomas Organ had taken the lead at the beginning, sending advisers to instruct the Italian workers to make three-piece guitar necks instead of the single-piece construction favoured by Jennings.

June 1965.

Below, published in the American music trade press in December 1965, a shot of the architect's model for the new EKO factory planned at Recanati. The photo in yesterday's entry is likely therefore to be from mid 1966 or later. No shot of the "old" factory (in which the first runs of Vox guitars will have been made) has so far come to light. It may be that parts had been destroyed in a fire (reported by Serrangeli).

December 1965, evidently not a drawing.

That the first runs of Vox guitars were made in the autumn of 1965 is clear enough - when Serrangeli joined EKO in September "a new range of Vox guitars....was added to the normal EKO production". Although little is known of the original arrangement made by JMI and Thomas with EKO, it is possible that it also encompassed - or at least envisaged from the outset - the making of organs.

If it did, the fire at the Vox Works in Erith in early December 1965 will have pushed all that to the fore. It is probably no coincidence that the first EKO circuit diagrams for the Continental (single manual) were drawn up in that month, the earliest of them 9 days after the fire.

During the course of 1966, the Jennings-Thomas-EKO arrangement became E.M.E.

13th June

Some notes on E.M.E. ("Elettronica Musicale Europea"), a joint manufacturing venture set in motion by Jennings, Thomas Organ, EKO, and the Italian government in 1966. Below, a note published in the English trade press in November 1966:

November 1966 - the broad outline and envisaged benefits.

Although EKO is not mentioned explicitly, production took place in the company's factory in Recanati - picture from this useful historical overview.

The new (E.M.E.) factory heralded in November 1966 was, in the end, set up in Montecassiano rather than Recanati and did not come into being until late 1968, by which time Jennings was out of the picture.

Where organs are concerned, E.M.E (perhaps one should really say EKO) - as has long been known - was charged with assembling Vox single and dual manual portables, the former from early to mid 1966, the latter from 1967 (main production run). Also to be factored in is the likelihood of pre-production runs, ie. in the case of the Super Continental, a certain number of units made prior to 1967, some perhaps shipped as test cases / "first builds" to the USA and Europe. It may be that such things will eventually come to light.

The EKO circuit diagrams for the single manual Continental were first drawn out in December 1965, copied from Jennings originals. Material naturally continued to be sent out in the months that followed. A sheet produced by Jennings in November '65 was redrawn by EKO in June '66. Later Italian diagrams are marked E.M.E. and have "Thomas" rather than "Jennings" in small.

12th June

A small spread of new and updated entries have been added to the page on later AC10 Twins. Further material to be incorporated soon. It may be necessary to split serial numbers in the 3000s off onto a short page of their own in due course.

11th June

Thanks to Jim, a shot of the warranty documentation issued with Italian-made Super Continental serial number 0429 by Thomas Organ, no dates present unfortunately. The pic has been added to the new page linked below.

10th June

A page has now been started to bring together material relating to the manufacture of Vox Super Continental organs in Italy. This will be linked up in due course with a forthcoming page on the production of Vox Super Continental IIs in Erith, and probably also with pages (to follow) on the production of single manual Continentals in the USA (the V301H) and Italy (the V301E).

9th June

A slightly better image of the earliest shot of a Continental in an American shop: the Hal Morris Music Mart (Hal in the picture), Lansing, Illinois, April 1965.

April 1965. In the background, an AC50 Foundation Bass set. On the wall, a copy of the earliest Thomas Vox illustrated catalogue "The Million Dollar Sound".

8th June (2)

Power supplies in Italian-made Vox Super Continental organs. Supers destined for the USA evidently left the E.M.E. factory with supplies that worked primarily from 117V (as stated on the serial number plate):

Italian-made Super Continental serial number 2117.

Italian-made organs destined for Europe left with plates supplied by Jennings as indicated in the entry for the 7th June below (note 5). These gave the operating voltages as 110/250V.

Italian-made Super Continental serial number 1774.

Was it possible for owners to adjust the operating voltage for Italian Super Continentals sent to the USA? - i.e. was there somewhere on the power supply a jumper for 117/250V (or perhaps 230V rather than 250V)? So far pictures would suggest not.

The Super Continental seems first to appear in Thomas pricelists in July 1966, presumably having been displayed at the NAMM show in Chicago (10th-14th July) and at the company's promotional event at the New York Hilton ten days later. The earliest shop advert that has come to light however is from March 1967 - after that a growing stream of adverts across the USA. Distribution may have been slow (and unexpected) initially.

Billings, Montana, March 1967. "Didn't know it was coming" could of course just be sales patter, but....

To judge from serial numbers and the dates on inspection stickers, E.M.E. only began shipping Super Continentals in sizeable numbers to the USA in 1967. As mentioned below, number 52 (0052) was inspected at factory in February.

8th June

A quick way to distinguish English-made Vox Super Continentals (I and II) from Italian-made: the position and form of mains switch.

Detail from the JMI promotional photo.

Early English-made Super Continental, light within the body of the switch.

English-made Super Continental II, c. 1967/1968.

On Italian-made Super Continentals, lamp and switch are side by side:

Serial number 0816, inspected at factory in Italy in May 1967.

Promotional photos published by Thomas Organ seem invariably to show Italian-made Super Continentals, below a Mark II from the standee featuring The Monkees:

Detail from the Monkees standee, early 1967.

7th June

Some notes, provisional for the time being, on Vox Super Continental (dual manual) organs:

1) - Relatively few dual manual Continental Is were made in Erith, sales probably confined to the UK and perhaps Europe. Serial numbers began at 5000. Super Continental IIs (introduced in 1967) followed in the same sequence.

2) - The lowest serial number of an Italian-made Super Continental that has come to light so far is 0052, the sequence presumably beginning at 0001.

3) - Final inspection of serial number 0052 took place at the E.M.E. factory in February 1967. Number 0816 was inspected in May 1967, and 1017 in August '67.

4) - Early runs of Thomas Organ serial number plates contain a spelling mistake - "DARTFORT" for "DARTFORD". This was remedied in a new type of plate brought into use by number 2117, mention of Dartford omitted - see below. Both types of plate were probably made up in Italy - note the presence of a comma rather than a decimal point in "0,125 AMPS".

5) - One regularly finds Italian-made dual manuals with English-made serial number plates. The actual numbers registered seem always to be part of the Italian sequence however. It is likely that Jennings provided these plates for the organs shipped by E.M.E.to Europe.

Italian-made Super Continental serial number 1017.

Italian-made Super Continental serial number 2117.

6th June

Entries for five more AC30 Twins with serial numbers in the 12000s have been added: 12064T, 12329N, 12365N, 12845TB, and 12928N. Select pictures to follow, as ever.

The entry for AC30 Twin serial number 16845, made up from at least two different amps and currently on sale in California, has been updated.

5th June (2)

A couple more things in relation to the previous entry. The contacts are likely to have been formed from nickel silver ("German silver") wire, used by Jennings for its valve console organs from the mid 1950s. The "Model G" is expressly said to have had German silver.

In December 1955 Les Hills and Bob Wittington applied on behalf of Jennings for a patent for a new form of contact assembly. This was granted in January 1959. Although the conductive rubber strips described in the patent document and various other elements are not present in the Continental, the design is essentially the same. As for immediate or intermediate precursors, the starting point for the Continental may well have been the solution arrived at for the Jennings "Model H" of 1958/1959 (also a 49-note keyboard).

Plaque on the front of the contact assembly, Continental from mid 1963.

5th June

Below, a detail of the key contact assembly of the Continental from mid 1963 featured on pages gathered here. The signals from the note generators are always on but earthed to ground in the assembly until a key is pressed.

When a key is pressed, four versions of the note are passed to the drawbars - effectively tone shapers and mixers - to the left of the keyboard.