VOX AC100 - UPDATES AND NEW INFO
July to December 2020
Some new material added on the page on 115-119 Dartford Road, the Vox Works, principal among which the two pictures below, taken by Derek Underdown, c. 1955. Thanks to Toni Standing, Derek's daughter, for permission to use them on the site.
Numbers 117 and 119 Dartford Road. Number 117 is still the Fish and Chip shop. Jennings had acquired the building by 1956.
The rear portion of number 117 with the "huts" behind number 119. In the 1960s, the "huts" housed among other things the Artists' Loan equipment - i.e. the amplifiers and so on lent out to groups. At least one surviving AC50 (which had gone out for a time to the Chris Barber band) is known to have come from these huts - purchased at a Dartford Road sale, c. 1967.
It turns out that the "Million Dollar Deal" of August 1964 - see this page - was not the first of that amount claimed by Jennings. Below, a news item in "Accordion Times", January 1953.
In 1964, one million dollars was £534,000; in 1953 $1m was around £383,000 - still a considerable achievement if the order actually did come to pass. The suspicion is it did not though. Univoxes are not common in the USA.
"Accordion Times", January 1953.
"Melody Maker" magazine, 29th March, 1952, an early ad for the Univox, which was added to the Jennings catalogue in early 1952.
Keith Relf of The Yardbirds, National Jazz and Blues Festival, 6th August, 1965. JMI provided at least four AC100 SDLs for the event. During The Who's act, six can be seen on stage - further pictures on this page.
1st December (2)
Brenda Lee, probably the Royal Command Performance, London Palladium, 2nd November, 1964 - on stage one of the JMI loan AC80/100s (with basket-top trolley). Also on the bill were: Tommy Cooper, The Bachelors, Cilla Black, Millicent Martin, Kathy Kirby, Morecambe and Wise, Gracie Fields, Jimmy Tarbuck, The Shadows, Cliff Richard, Bob Newhart, and Lena Horne.
The Beatles were in Belfast on the evening of the 2nd, along with Sounds Incorporated, which had sometimes served as Brenda Lee's backing band. Sounds Incorporated backed Mary Wells on the Beatles' November tour.
"The Searchers", Palace Theatre, Douglas (Isle of Man), July 1964, Tony Jackson on bass - his amp either a thin-edged AC50 or AC80/100 on top of a Foundation Bass speaker cabinet. Front of stage, a T60 or 2x15" cab.
Detail of a picture from the Isle of Man photo archive.
A great detail from a picture taken in early August 1964 by Leslie Bryce of The Beatles Book - one of the two new black-fronted AC80/100s (and speaker cabinets) consigned to John and George by JMI around the 20th of July.
The amps were first used in Stockholm, 28th and 29th July - see this page. George used the one pictured below for the two concerts.
As the serial number of the other amp was 180, the one below is likely to have been either 179 or 181.
Serial number 179 or 181 (?). Detail of a photo by Leslie Bryce of The Beatles Book.
Just to note that AC100 serial number 1689 survives in Spain. Its electronics have been renewed, though the transformers are the originals.
An advert placed in "Melody Maker" magazine, 5th March, 1966, by Sound City. Note the PA equipment available - Vox PA50 and PA100s with column speakers, 4x10" and 4x12". The 4x12" columns were new in August 1965.
"Melody Maker" magazine, 5th March, 1966.
A page - available here - has now been started on banners issued by JMI to dealers, shops, and so on. They were often displayed also at Trade Fairs and promotional events. English banners are three feet wide. Those produced in (or perhaps for) the USA are wider.
Both banners are 3 feet wide.
Pics of AC100 serial no. 532, built according to the "100W Amplifier" circuit diagram but converted to cathode bias in recent times, are now here.
Pictures of serial number 797 from late 1965, now added here. A good number of AC100s with numbers in the high 700s and low 800s were evidently exported to Italy. This one was sold and used in England.
Replacement transformers for the AC100 continued to be offered in both Germany and the USA long after the model ceased to be sold / promoted - from 1966 in the USA, and from 1968 in Germany. Below details from two German Vox catalogues (March 1968 and mid 1969), and from the Thomas Organ dealer parts register of April 1969.
Detail from the JMI German catalogue of March 1968. The catalogue as a whole is available here. In 1968 188DM was equivalent to around £20-£21.
Detail from a "Vox Sound Equipment Limited" fold-out German catalogue/brochure of mid 1969.
Detail from the Thomas Organ Vox dealers pricelist of April 1969. Price to dealers is on the left, retail price on the right. In 1969 $20 was equivalent to around £9-£10, and $34 equivalent to £16-£17 - so a little cheaper than in Germany.
Below, pictures of AC100 serial number 532, built according to the fixed bias 100W Amplifier circuit in the late summer of 1965, and converted in recent years to cathode bias.
The first "100W Amplifiers" had white warning plaques; a small run followed without. With serial number 532 the plaques return (number 531 has none).
The "100W Amplifier" circuit was the first fixed bias circuit. The AC100 Mark 2 followed soon after, introducing the brimistor, a form of thermistor designed to reduce inrush current.
Just to note that two fixed bias AC100s came up for sale recently: in the USA, serial number 532, originally built to the "100W Amplifier" circuit but converted in recent years to cathode bias; and in the UK, serial number 797, an AC100 Mark 2.
Whether serial number 532 was long in San Francisco, as serial number 531 was, is unknown at present. Nothing is known unfortunately about the history of 797. Pictures to follow.
Pictures from the Spanish magazine "Discobolo", 1st June 1967 - the "Festival de Idolos", Madrid, Palacio de los Deportes, May 1967, sponsored by the department store "El Corte Ingles".
Note the four AC100 cabs and trolleys on stage, along with a 7120 cab and trolley. No sign of the amps though - perhaps on the stage apron by one of the risers.
Below, some old pictures of the scarce Thomas Organ Vox pricelist of autumn 1965 - effective 21st September 1965. The list tallies best (though not item-for-item) with the "British Sound" catalogue. In much the same way, the pricelist of April 1965 fits the earlier "King of the Beat" catalogue.
The "King of the Beat" for instance has the Vox Berkeley valve (tube) amplifier with two inputs. The "British Sound" has the "Berkeley II" transistor amplifier with three. The "King of the Beat" also has the "Kent", the AC15 renamed, later deleted from the Thomas Organ range.
A growing collection of Thomas Organ documents can be found on this index page.
Although there is no shot of the price of the AC100 (the "Super Beatle" in the USA), one can compare other prices with those set out in April 1965. The "Bristol Bass" (T60), called with a large degree of imagination a "powerful amplifier" in September 1965 - one might also say nerve - is $749 without covers or stand. In April 1965 it was $635. Quite a rise.
Some more to come later on the deletion of the AC100 from the Thomas Vox catalogue and the appearance of the solid state "Beatle", an engineering prototype of which was assessed by Dick Denney in Sepulveda in early November 1965.
A detail from the JMI flyer for the Russell Hotel Trade Fair, August, 1965: - the PA mixer (Mark III), and the new LS60 speaker columns with 4 x 12" drivers, designed to accompany the Vox 100W and 150W PA amplifiers.
The page on Vox mixer units has been updated. Mark 1 and Mark 2 mixers are extremely scarce these days.
An alternate version of the JMI flyer for the BMII Trade Fair, August, 1965 - pages 1 and 4. The version in red and black - on this page - is probably earlier. On page 4 of the red and black version there is no "JMI" in the "NEWSLETTER" banner.
Pictures (screengrabs) of the two AC100 SDLs that Juan y Junior acquired in late 1965 / early 1966. The first set of pics comes from their film vehicle of October 1968. The last is from 1970.
Also on stage two Vox UL7120s. At least two other Spanish groups had a pair of 7120s.
Note the red warning plaque on the back of the AC100 amplifier section and the three-line serial number plate.
The picture immediately above is from a promotional film of 1970.
Pictures of the Jennings PO.1 Pulsation unit (rotary speaker) that recently came to light are now available on this page.
The new page on the Jennings (JEI) J71 organ has now been started. Thanks again to Ben for pictures of the superb example illustrated.
Just to show the deletion of the AC100 from catalogues printed for the German market in 1967:
JMI German catalogue, March 1967, page 2.
JMI German catalogue, printed September 1967, page 3. The T60 had also been phased out.
Coming shortly, further pictures of a superb Jennings J71 organ, complete with its cables and pedals, and a Pulsation PO.1 unit. Thanks to Ben.
Some more on the question of when Jennings acquired 115 Dartford Road. The answer is 1953, soon after the previous occupant (an Estate Agents) vacated. The "Unity Works" is mentioned in adverts in "Melody Maker" magazine, late 1953; and an artist's impression of the front figures below, 6th Nov. 1954:
"Melody Maker" magazine, 6th November, 1954.
A detail from the JMI catalogue printed in September 1967 for the German market, 1968.
Two hybrid PAs are encompassed - the MC50 and MC100 - solid state preamp (with meter) and valve power amp; and above them, two fully solid state units, the new PA50 and PA100. These last were promoted in the UK catalogue of April 1967.
The fact that prices are noted against the solid state PAs tends to suggest that they were actually available. To date none has surfaced, however. It seems likely that if reasonable numbers were made, they did not sell well.
Further pictures of serial number 241 (AC80/100, black panel, late 1964 or early 1965) are now available here.
The text of the piece on JMI published in the Telegraph magazine, 14th May, 1965, is now available on the page on Tom Jennings.
Two adverts in "Accordion Times" show that number 115 Dartford Road had been acquired by Jennings by January 1955, and number 117 by 1956. The page on the Jennings works has been updated.
Detail of a Jennings advert in "Accordion Times", January 1955 mentioning "Unity Works", which was number 115 Dartford Road.
Detail of another Jennings advert in "Accordion Times", January 1956, one of the first, if not the first, to mention the complex as a whole (i.e. numbers 115-119) explicity.
The page on AC80/100s with black panels is in the process of being updated and expanded with further details on components and so on.
It may be possible to add pictures of an amp currently in Florida. At any rate, additional shots of serial number 241 will be added soon.
18th September (2)
Nestling in a huge batch of Melody Makers from the late 1940s and early 1950s, the issue for 16th December, 1950, recording the opening of the Jennings shop at 100 Charing Cross Road. The event was also signalled in the Jennings house magazine - "The Accordionist and Harmonica Player" - see this page.
"Melody Maker" magazine, 16th December, 1950. The celebration lunch, 6th December. Allan Billington was the first manager of the shop. Later, in 1955, the Jennings "London Accordion Centre" was opened in the basement.
Just to say the list of Vox dealers has now been given a separate page here. Notes on sources, recording where possible the year (perhaps month) in which particular businesses are known to have been or become dealers, will be added in batches.
17th September (2)
It may be necessary to give the list of Vox dealers a page of its own, partly for convenience, partly to provide space in some form for the group of dealers named in "Billboard" magazine, 4th October, 1967 - posted on the Vox Supreme website ( on this page, entry for 18th June). The touring party will have seen the JMI solid state amps
"Billboard" magazine, 4th October, 1967.
Four more "Exclusive Vox Dealers" added to the list on this page:
Greencastle (Indiana), Houck's Music; Yakima (Washington State), Lee's Music Shop; La Crosse (Wisconsin), A&W Music; Dayton (Ohio), Bernie's.
Advert in the "Amigoe de Curacao", 19th September, 1966. Curacao is in the Dutch Antilles off the coast of Venezuela. The 120 watt amplifier mentioned though not pictured is probably at this date the UL7120. The AC100 was never described as being more than 100 watts.
Seven more US dealers - all termed "Authorised" or "Exclusive Vox Dealer" - added to the list on this page:
Fresno (California), Sherman Clay Music; Rochester (NY State), Midtown Records Musical Instrument Dept.; Chicago (Illinois), Roselle School of Music; St Louis (Missouri), Northland Music Center; Richland (Washington), Alan's Music; Billings (Montana), Ed Schaeffer's Piano and Organ Center; Akron (Ohio), Akron Music Center; Cuyahoga Falls (Ohio), Akron Music.
Below, a photo by Peter Keen published in the "Weekend Telegraph" magazine", 14th May, 1965 - testing at Dartford Road. In the booth on the left, a large box AC50, on the right an AC100.
In the foreground, T60 amplifier sections and speaker cabinets, an AC30, two more AC50s (probably not AC100s), and a pile of covers.
"Weekend Telegraph" magazine, 14th May, 1965.
Below, a snippet of a report from "The Spririt Lake Beacon", 18th August, 1966, posted in full just under a year ago - 15th Sept., 2019.
One of the intriguing things about the report is the mention of the "Vox" warehouse in Evanston (north east Chicago). In fact, this is likely to have been the main "Warwick Electronics" warehouse, mentioned in the biography of Lawrence (Larry) Haggerty, President of Warwick. Warwick owned Thomas Organ.
That Hampton called Evanston is suggestive. Perhaps he knew that English-made valve amps - for The Yardbirds, an English group - were likely to be in store there. Evanston "determined that the right equipment was available". American-made solid state amplifiers were rapidly replacing English-made equipment in the shops at this time.
On a broader level, it may have been Evanston that received, in the first instance, the shipments of Vox equipment flown to the East Coast from England in the last third of 1964 (Sepulveda receiving the shipments flown to the West).
But where exactly in Evanston was this warehouse? Searches have so far turned up next to nothing.
"National Cyclopaedia of American Biography", 1967, s.v. "Haggerty, Lawrence George".
"Spirit Lake Beacon", 18th August, 1966.
Six new entries added to the list of US Vox dealers - Philadelphia (Pennsylvania), Wurlitzer/Steinway Pianos - (thanks to Joe for the info); Hazelton, Penn., Staff Music Center; Munster/Lansing, Illinois, Hal Morris Music; Phliadelphia (Penn.), Gilbert Music Co.; Long Beach, California, Gilbert Music Co.; Albuquerque, New Mexico, King Music Co.
Screengrabs from a video of the great Billy Sheehan at the Hollywood Guitar Center on the 21st of October, 2010. On the back wall an AC100 SDL.
It may be possible to identify the amp by the way the grille cloth was fitted to the box - the arrangement of diamonds on the front - and the position of the "VOX" logo in relation to the diagonals. As the fitting of grille cloth and so on was done by hand, every amp is slightly different.
If a better grab of the front can be got from a different snippet of video, it will be added here.
A good detail from a different piece of video. The amp has corner protectors with single pins, so prior to mid 1966:
The picture below from "The Kentish Times", 4th July, 1964, records Lonnie Donegan's visit to 115 Dartford Road on Monday 30th June 1964. Dartford Road often had visits from musicians, ranging from the band of a local Kent branch of the Salvation Army, to chart names, as Donegan was. Is that an AC80/100 behind him?
Mr R. D. Clark is of course Reg Clark, General Sales Manager of JMI. This image will be replaced by a better one as soon as possible.
The number of diamonds vertical on the front tends to suggest that this is indeed an AC80/100. One can just see the white piping of the lower edge underneath the guitar cable which trails across the front above it.
A note on the black-topped transformers used by Vox in AC100s from early autumn 1965; in AC50s from 1966; and in the solid state range from late 1966 / early 1967. They were all made by the same company. Many units still retain their three letter date code - stamped in white on AC50 and AC100 transformers, and in black on those of the solid state amps.
AC100 serial number 520, an early "100W Amplifier", made in the early autumn of 1965. Black transformers and non-Woden choke.
First, just to recapitulate the part numbers assigned by Vox to the transformers. These were stamped on for Vox by the manufacturer (i.e. they were not the manufacturer's numbers):
AC100 mains: 66775.
AC100 output: 66776.
AC100 choke: 66429 - often a Woden choke (with itw own number) was used instead however.
AC50 mains: 66522.
AC50 ouptut: 66523.
AC50 choke: 66524.
Supreme and Super Foundation Bass (solid state) mains: 13759 (corrected).
Supreme and Super Foundation Bass (solid state) driver : 13478A.
Just to give these two instances from the solid state range. Transformers for the other models also begin 13xxx.
The easiest place to see the white date codes in AC100s and AC50s is on top of the choke. The first letter is the year, beginning with "G" = 1964, "H" = 1965, "I" = 1966 and "J" = 1967. The significance of the other two letter is not fully resolvable yet. The last may be the month - "A" = January and so on on. No letter higher than "L" has come to light so far. But a good many end in "B".
The choke of AC100 serial number 531. One can just see the white date code: "GTB"
A dead output transformer from an AC100 made in late 1965 / early 1966. The code is "HGL".
AC50 serial number 6474, mid 1966, its choke stamped "IQB".
AC50 serial number 7430, early 1967, its choke stamped "JQB".
A Super Foundation Bass mains transformer, mid 1967 - stamped "JSB".
The white date stamps on mains and output transformers are often hard to see, either having faded, or being low down close to the base of the chassis. But it may be possible to post details of others. Further notes on these transformers to follow.
San Francisco, May 1991: Sherman Clay had at least two AC100s, priced initially at $975 each, then $695. In all likelihood these were just the amplifier sections:
"San Francisco Examiner", 22nd May, 1991.
"San Francisco Examiner", 24th May, 1991.
Some general shots for the time being of the all valve metalclad PA100 mentioned in the previous entry. A couple of pages of details are on their way.
In spite of what one may read, these amps were not uncommon in their day. Adverts for new ones figure fairly regularly in "Melody Maker" magazine in the late sixties and early seventies. The rapid advances in PA technology in this period, however, doubtless led to the eventual junking of many. Survivors are thin on the ground these days - a great shame as the amps are constructed extremely well. For others, see this page.
8th August (2)
Coming soon, pictures of a further all valve "metalclad" Vox PA100, assembled for Jennings by Triumph Electronics in early 1967 (pot codes of December 1966). The amp was used regularly by the English band "Moonstone" in 1972 and 1973, but only sporadically thereafter. Alan Pyne, who had taken over 119 Dartford Road when "Jennings Electronic Industries" gave up the ghost in 1975, revalved it in 1979.
This PA100 is of the final type assembled for JMI by Triumph. Phenomenally heavy, as they all are due to their massive transformers (made in this case by Drake), its speaker outputs are standard 1/4" jacks rather than Bulgins.
Pyne's label inside the metal case.
Below, select pictures of the Vox catalogue issued for the German market in March 1967 - "III/67". Various amplifiers in the 4- and 7-series range are encompassed, along with the new solid state line (last couple of pages). The complement of fully valve amps is small as one might expect: the AC30, AC50 and AC100. The PA amps (PA50 and PA100) are hybrid, much as the 7-series - transistor preamp, valve power amp.
One could buy the amplifier sections and speaker cabinets separately - unlike in the USA where sets only were supplied new (1964-1966).
In early 1967, there were around 11.2DM to the pound. The AC100 SDL in Germany therefore cost the equivalent of £357; the amplifier section alone £205; and the speaker cabinet (and presumably trolley) £152.
The list prices in the UK at the time were £252 (AC100 SDL complete); £105 (amplifier section); and £147 (the SDL speaker cabinet). The JMI retail price list of April 1967 can be found on this page.
Page 2. Note that the AC100 is entitled "Super De Luxe - Beatle - Bass". The description describes the standard SDL however.
Serial number 226 now registered here. As one might expect, the amp is similar in certain respects to serial number 225 - thick-edged box, no corner protectors. Probably made for export to the USA in the last quarter of 1964. Perhaps in company with serial number 225 initially a JMI demonstration/loan amp too. But that for the time being has to remain surmise.
Serial number 226. Grille cloth and logo are later replacements.
27th July (2)
An aerial shot of Dartford Road taken in 1953. Number 115, formed of two adjoining parts (one behind the screen wall), is indicated by the arrows. To the right, on the corner, is the garage. At the time the photograph was taken, number 115 was an Estate Agents. The buildings were acquired by Jennings by 1958 at the latest, becoming the works or "Unity House". For more, see this page.
A note on the cabinet-maker P.A.Glock, which made the thin-edged boxes for the AC80/100 (and some of the thick-edged too).
Up to 1954, the business was based in Belvedere, Erith. Prompted by the need for more space, Glock moved in that year to 1b London Road, Crayford, just over a mile up the road from the Jennings works on Dartford Road. The company remained in Crayford until 1991 (not 1989 as previously stated).
The red dots mark the respective positions of the P.A.Glock works in Crayford (top left), and the Jennings works on Dartford Road (lower right).
1b London Road, marked as "Factory". A little to the north were the Crayford Saw Mills.
1b London Road, Crayford, photographed from the air in 1934 (i.e. twenty years before Glock moved there).
A new page begun on the JMI buildings at 115-119 Dartford Road, further material to be added shortly.
"Squeeze Box" magazine, May 1949. A detail from the Jennings advert on the back page - 119 Dartford Road, Tom Jennings's first premises.
A rare early colour picture of an AC80/100 - The Stones, Brussels, 18th October, 1964, rehearsing at the American Theatre for their appearance on Belgian TV (BRT). Picture from "Muziek Expres" magazine, April 1965.
The black-fronted AC80/100 was provided by JMI for The Stones' short European tour - Brussels (18th October) and Paris (20th October). It presumably returned to JMI shortly thereafter. The Stones did not use it again. For further pictures, see this page.
A couple of adverts relating to Vox in US newspapers, June 1965 - free copies of Vox Teen Beat vol. 1, no. 1 available at the House of Pianos and Organs, Miami (Teen Beat vol. 1, no. 2 did not appear until later in 1965); and a promotional event in Honololu led by Paul Revere and The Raiders.
Further ads from June 1965 will have a page of their own soon in the newspapers 1965 section.
"Miami Herald", 13th June, 1965.
"Honolulu Star Bulletin", 25th June, 1965
A pair of Line Source 40 column speakers turned into a pair of stand-up cupboards, the original (?) green covers still present:
16th July (2)
A new page begun on Tom Jennings, collecting together for the time being articles on or by him from the 1950s and 1960s.
"Melody Maker" magazine, 16th December, 1967, reporting the appointment of a receiver for Royston Industries and Jennings. The interesting thing about the piece is the explicit mention of the extent of Royston's debt ("overdraft") - £1.6 million, a sizeable sum in those days. Other sources generally only say "heavily in debt" or words to that effect.
See the material gathered together on the page on Jennings Musical Industries in late 1967 and 1968.
"Melody Maker" magazine, 16th December, 1967.
Below, photos of the Dave Clark Five, during their residency in late January and early February 1964 at "The Royal", Tottenham, with a couple of custom JMI PA speaker cabinets. Good colour footage was shot by a Pathe newsreel team (available on the Pathe website).
Vox made sure its logos were prominent everywhere - adding new ones (somewhat hastily) to Mike Smith's organ in places where normally there was none. The cabinets, which both have swivel side stands, look as though they contained two twelve inch drivers.
From left to right, two AC30 Super Twin cabs driven by one of the group's AC50s; one of the two custom cabinets to the left of the curtain; a LS40 speaker column swung upright (and therefore upside down) on its stand.
The other custom cabinet on the left hand side of the stage.
Shortly before the residency at Tottenham, the band was photographed with a couple of smaller cabinets with Vox swivel side stands - probably 15" speaker units given the apparent depth of the cabinet. But the grille cloth is plain.
The Locarno, Basildon, 5th or 12th January, 1964.
Thanks to Walt, pictures of an early AC100 Mark 2. The serial number plate (with the number 785), warning plaque, and trolley are reproduction - but the number cannot be far off the original.
Thanks to Bill, pics of an AC100 made by Triumph in 1967, signed (as numbers of chassis were) by Graham. The amp is registered here.
The unusual placing of the "BASS" runner can also be found on a small number of AC30 Super Twin amplifier sections.
Chassis with metal guard round the EL34s. Guards were introduced in late 1965 / early 1966.
Note the eyelet preamp tagboard. The red capacitors were made by RTC ("Radio Telegraph Company"). Triumph had used these in the AC50s it produced for JMI in 1964.