Vox AC30 website updates
Thanks to Sean, pictures of Super Twin amplifier section serial number 7167 N, from mid 1963. A previous owner used the amp in sessions with Joe Meek.
A black panel AC30/6 from late 1960, sold in Italy in 2014 - pictures here - and again relatively recently on Reverb. The speakers have date codes 16JE and 23JE = 16th and 23rd September 1960. Note however that the "VOX" label is heavily scratched. The Celestion label on the BO24, on other hand, is comparatively clean. The solder on the BO24 speaker terminals is not original. The pink and yellow speaker wiring is however.
Details of the JMI catalogue and pricelist printed for the Frankfurt Trade Fair - the "Musikmesse" - of March 1968 (the date of the catalogue). This was the last trade show of any sort that JMI attended. Soon after, the company ceased trading, to become "Vox Sound Equipment Limited" (VSEL) in the late summer of 1968.
The AC30 Top Boost. Six inputs, three channels with their own volume controls, two of the inputs for vibrato, operated by a footswitch. General tone control and dedicated treble and bass.
The two types of stand (in order) are swivel and fixed.
The page on AC30s with serial numbers in the 17000s, late 1964 / early 1965, is now up. From 1965, speed of production dropped significantly. In 1964, around 8,000 AC30s were produced. From 1965-1968, only around 6,000.
22nd October (2)
The page on AC30s with serial numbers in the 17000s, late 1964 / early 1965, coming shortly.
A couple of interesting things on Reverb at the moment. (i) a black panel AC30/4, probably from early 1961, original transformers in place. The amp is listed here. No serial number plate or relevant date codes visible on the components unfortunately.
Five of the six original circular ribbed black control knobs (with small inset pointers) survive. These are of the type illustrated in the JMI booklet of early 1961.
The AC30/6 panel illustrated in the JMI booklet, same type of knob as those on the AC30/4 above.
(ii) an AC30 Super Twin amplifier section, serial number 3134, late 1964 or early 1965, its tag still present - "VOX" in cursive - i.e. the earliest/first style of tag. Listed here.
A little more on Woden transformers. As it stands, the latest date codes on batches with green tops (the earliest type) appear to be "AV" = January 1964. The chokes accompanying these generally have "BV" = February 1964.
The new batches with plain metal tops came in later in the year, the earliest being "JV" = September 1964. Woden also made new batches of transformers for the AC80/100 at this time (amps with black control panels), along with a small run for the AC50.
So far no Woden AC30 transformer has turned up with a date code between February and September 1964. For the most part, Albions and Parmekos were used in this period.
The new batches of Woden AC30 output transformers (with plain metal shrouds) have a simplified internal and external construction. Externally there is only one red wire for the HT instead of a pair, and single wires for the secondaries (the output taps) instead of pairs. From a constructional standpoint, the new Wodens for the AC80/100 were exactly the same as their forerunners, however. Only the shrouds are different.
To date, the latest new-style Wodens for AC30s that have come to light are from November 1966 (serial numbers in the 22000s) - Woden date code "LX". Whether there are any with still later codes remains to be seen.
Serial number 6443B now added here. The latest observable element is the TCC preamp filter cap, date code "TM" = December 1962, so the chassis was assembled (by Westrex) early in 1963. What may be the Westrex inspection stamp survives by the underside of the output transformer. Thanks to Glen for the pictures.
One can make out "WEC" which is likely to be "Western Electric Company" (Westrex) followed by an "L" and a smudge, perhaps "Ltd".
Currently on ebay.de, serial number 22177, very little changed since it was made in early 1967. Visible date codes are - blue Erie/Hunts cathode bypass caps "UWY" = 10th week of 1966; Woden transformers and choke "JX", "KX" and "LX" = September, October and November 1966; and the red CCL 8uf capacitor "L6" = December 1966.
Note the red Lemco capacitors and the large parti-coloured Dubilliers at right.
16th October (2)
Picking up from the entry on Vox in Australia - below (15th Sept.) - an advert placed in the "Canberra Times", 29th June, 1964, by Donoghoe's Music Centre, Queanbeyan (nr Canberra).
Donoghoe's signalled the availability of Vox amplifiers on 15th June, but only as part of a general indication of what was in stock.
"Canberra Times", 29th June, 1964. The ad is a version of the one placed by Nicholson's earlier in the month in the "Sydney Morning Herald".
13th October (2)
Interesting how one thing leads to another. Below, Russ Sainty and Rhet Stoller (with guitar) at the California Ballroom, Dunstable, at some point in 1960. The California opened in March of that year and Sainty and Stoller's band the "Nu Notes" featured regularly.
In the background, two TV Front AC30s, the one with "ROY" on the front belonging to Roy Toft, rhythm guitarist of the group.
Tony Howard and the Dictators, winners of the Bournemouth "Big Beat" competition in February 1964. Picture from this page. The amp looks very much like an Extended Frequency AC30, just released at that point. Note that an Extended Frequency AC30 was illustrated in the Rhet Stoller competition of much the same date.
Rhet Stoller competition (organised by Larry Macari). Detail from "Record Mirror" magazine, 14th May, 1964.
Below, the advert for a number of Vox amplifiers in "The Shadows Modern Electric Guitar Tutor" from early 1963. The AC10 Super Reverb Twin was new in February '63 - see this page. The prices correspond with those given in "Melody Maker" magazine in early February too.
The "Modern Electric Guitar Tutor" also contains some excellent material on the Vox Phantom guitar.
"Melody Maker", 21st January, 1956 - a fiendish thingy. To judge by the description, a preamp (with octal socket input and output) designed to be plugged into the power section of an electronic keyboard - ie. an organ or Univox with built-in speaker. The keyboard could be plugged back in via the octal socket on the fascia. Doubtless a Derek Underdown design.
"Melody Maker" magazine, 21st January, 1956. Note the Jennings badge on top of the unit. Presumably a set of instructions was provided.
The page on serial numbers in the 16000s is now up. Some of these amps are likely to have been made around the time that the first big American order came in in late August 1964.
1st October (2)
Just to signal the presence on Reverb of a pre-LOC black panel AC30/6 from late 1960 - the Celestion speakers (one BO24 and one CT3757?) have date codes "16JE" and "23JE" = 16th and 23rd of September 1960. No other relevant component dates can be seen.
To accompany the previous entry, the Jennings advert, placed in "Melody Maker" magazine, 1st May, 1954, for the BIF Fair of that year, held at Olympia in London. The ad has been said to contain the earliest mention of a "VOX" amplifier. Note the output - 15 to 25 watts. This was certainly not Derek Underdown's G1/10 - possibly a version of his "30 Watt Amplifier"?.
If "Accordion Times", April 1954, turns out to have an ad along the lines of the one published in April 1955, it will be posted here.
"Melody Maker" magazine, 1st May, 1954. Note also the "Rotary Foot Swell Ccontrol" (first advertised by Jennings some months earlier). Rotary foot pedals were further developed by Tom Jennings's post-JMI company - "Jennings Electronic Industries" (late 1968 to 1975). But in the 1950s Jennings as ever, was not without competition - Selmer had its own rotary foot pedal. Selmer and Jennings played leap-frog with other things too.
"Accordion Times", April 1955, Jennings advert for the stand at the British Instrument Fair. Note lower left, the portable organ on chrome legs, a valve precursor - presumably valves - of the Continental of 1962, and the amplifier, doubtless a species of Derek Underdown's G1/10.
"Accordion Times", April 1955.
28th September (2)
Entries for eleven more AC30 Twins have been added: serial numbers 6424, 7292, 7298, 7475, 8243, 9577, 13706, 14629, 15344, 15641 and 15888. Further pictures will be added soon where possible. The page on amps with serial numbers in the 16000s will be coming shortly too.
There are entries also for Super Twins 3073, 4033 and 4593, all in Sweden. There are no pics of these at present though.
As an adjunct to yesterday's entry, the lowest Burndept chassis number encountered so far - number 01028. The serial number plate unfortunately has parted ways with the amp.
The designation "AC.36" was simply the early short-hand for AC30, six inputs. On later chassis, one finds "AC30/6", the earliest known instance currently being chassis 01689 (AC30 serial number 7061).
The 29th chassis stamped with a number by Burndept. Just to re-iterate, this does not mean that it was the 29th chassis populated with components, nor that JMI put chassis into wooden cabinets (when the time came to make up an AC30 sale) in any particular order.
A couple of pictures to "top and tail" the change in the location of the chassis number stamped by Burndept on the chassis it produced. Early = on the plinth. Later = on the aluminium preamp upright. The change probably took place at chassis no. 02000, the series having been kicked off at 01000.
The 945th chassis *stamped* by Burndept. Not the 945th made or completed. The number is stamped on the plinth. The serial number of the AC30 is unknown
Chassis number 02238, stamped on the aluminium upright. AC30 serial number 9434.
A couple of great full-page Jennings adverts in "Accordion Times", January and May 1955, for the Jennings J50B and J50C Organs. Both have built-in speakers - the J50B one and the J50C two, the amplifier of the latter with a stated output of 20-25 watts. These are the organs for which Derek Underdown first designed amplifiers. It may be that the J50C had his "30 Watt Amplifier", the precursor of the AC2/30.
Strange to say the AC50, designed in the autumn of 1963, also had elements of Derek's 1950s amplifier - namely the bias circuit. See the updates page on the Vox A50 website. Derek did far more designing and implementing than he is normally given credit for. As far as the AC50 is concerned, Dick Denney probably came up with the preamp (based largely on the add-on AC30 Top Boost circuit).
"Accordion Times", January 1955.
"Accordion Times", May 1955.
The remains of an AC30 chassis from mid 1963, assembled by Westrex, and signed off in pencil by "DP", whose initials appear I think in at least one other chassis.
Two date codes are visible - the potentiometer "EK" = May 1963, and one of the gold-coloured TCC bypass capacitors - "UC" = March 1963.
The amp's serial number was probably therefore somewhere in the first half of the 6000s.
A brief jump back in time: - the first Jennings amplifier - front and back view - illustrated in "Melody Maker" magazine, 26th January, 1952. The name "Univox" was also used in March 1952 for the new portable electronic organ, which remained in production until 1966.
The covering was imitation lizard skin (used for early portable organs and the later G1/10 amplifier too). Output was 15 watts, pretty much the limit of a single speaker at the time.
Up to 1952 Jennings had recommended and sold amplifiers made by "Westbourne Sound Equipment" (WSE), which was based in Westbourne Grove, London.
"Melody Maker" magazine, 26th January, 1952. If an earlier dateable advert materialises it will be posted here.
"Muziekhandel Gerritsen", The Hague, 4th October, 1962, Vox amplifiers in stock - possibly AC30s given the mention of The Shadows.
Rotterdam, "Algemeen Dagblad", 4th Oct., 1962.
Muziehandel Gerritsen in the 1970s. Picture from the FB "Haagse Beat Jahren 60/70" page.
15th September (3)
A short note on the arrival of Vox in Australia, more precisely Sydney. This at present is simply the bare bones. A particularly valuable source is hard to come by - "Music Maker" magazine, which began in the 1940s - not to be confused with the English magazine of the same name which ran for around 18 months from late 1966. Info from MM will be posted as it comes to hand.
The magazine has, for instance, this great advert for Vox featuring "The Atlantics" - picture from this page.
"Music Maker" magazine, late 1964. Note the mention of Nicholson's of Sydney, Sykes in Melbourne, and Grice-Nicholson's in Brisbane.
So far as Sydney is concerned, the first shop to mention the arrival of Vox equipment was "Guitar City" in the "Sydney Morning Herald", 15th March, 1963. Note the presence of "soon":
The entry above is from the "Sydney Morning Herald", 23rd March, 1963, simply for the sake of clarity. The entry is exactly the same as the one placed a week earlier.
But the first indication that Vox equipment was actually available at "Guitar City" came on the 11th May 1964:
"Sydney Morning Herald", 11th May, 1964.
Nicholson's followed suit a few days later, having mentioned very little relating to Vox in its adverts up to this point ("new Vox guitars" on 15th December, 1963, but nothing else):
"Sydney Morning Herald", 16th May, 1964.
By June 1964, Nicholson's had become the sole Australian distributor, placing a handsome ad in the Beatles' Australian Tour programme, and larger illustrated ads in the "Sydney Morning Herald".
Nicholson's advert in The Beatles' Australian Tour programme. The Tour ran from 12th-30th June, 1964
"Sydney Morning Herald", 17th June, 1964.
Various pricelists and catalogues were printed by JMI for Nicholson's (and Sykes in Melbourne):
1966 prices. Picture from Jim Elyea's book, collection: Martin Kelly. Note that the "AC30 Expanded Frequency Twin Fifteen" is still available.
Late 1966 - promotional brochure for the solid state range, available in full here.
15th September (2)
Thanks to Marc, a further early copper panel AC30 has come to light, late 1961 or very early 1962, travelling under the serial number plate 9851N (and previously registered on the site under that number).
The chassis, assembled by Westrex, has a mis-positioned hole for the rectifier valve, white sockets for the EL84s, and the early form of vib/trem trimmer pot, fully rectangular rather than part rectangular part rounded.
The corners of the cabinet back boards are square rather than rounded. The cabinet may have been sent back to factory to be recovered in its current black pebble vinyl. Pictures have now been moved to this page.
The original serial number of the amp will have been high 4000s or low 5000s.
A new page has now been set up on a chassis from late 1962. Some pics (principally of the Haddon choke) were posted a month or so ago (28th July).
Just to note that in late 1962 / early 1963, Westrex began using gold-coloured TCC 25uf capacitors (rather than blue Hunts) in the preamps of its AC30 chassis.
A chassis from an AC30 with a serial number in the 10000s, early 1964 - Woden transformers with date codes "JU" and "MU", respectively September and December 1963. The brown inspection tag is still present, along with the purple Burndept chassis inspection stamp behind the wiring. One can sometimes make out the "shadow" left by inspection stamps on other chassis.
Further pictures of the TV Front AC30/4 mentioned below, are now here. The date code of the pot - "JH" - is October 1960, not September (as stated yesterday).
Some pictures coming soon, thanks to Valentin, of a TV Front AC30/4 from late 1960 / early 1961. The original cabinet was ingeniously reworked (decades ago) to accommodate the chassis alone. The original serial number plate is lacking.
In the preamp, one of the pots has the code "JH" = October (NOT September) 1960. Note the white pointer knobs.
It is easy to forget that in company terms JMI was still a relatively small concern in 1963. Its range had expanded in 1957/1958 and again in 1960, but it was not until 1964 that things really began to take off, thanks in the main to the high public profile of The Beatles and other groups. Even so there were black clouds overhead.
Some of what follows has been on the AC100 website for a while, but it may be useful to summarise here. In early January '63, Tom Jennings sold a controlling "interest" in JMI to "Royston Industries" - a means of recapitalising the business. Royston was effectively a holding company with a fairly specialised electronics portfolio - batteries (Vidor), aviation and aerospace (Burndept), and various tooling companies.
"The Guardian", 30th January, 1963.
The smallness of JMI was noted in a syndicated article published in October 1963 (section below) - "Vidor has been making losses for some years and Jennings is only a small concern".
"The Birmingham Post", 17th October, 1963.
The failure of the "Midas" flight recorder to capture the market as had been hoped eventually brought Royston down in late 1967. But even in the mid sixties, doubts were evident:
"The Observer", 22nd November, 1964.
On the 3rd September 1964 the Birmingham Post printed a synopsis of the Royston AGM (Annual General Meeting, attended by shareholders, investors, and so on). Profits for the Group as a whole were £271,271. The report on JMI was:
"MUSICAL INSTRUMENTS: This division increased its profits substantially and made a good contribution to the Group's results. Your Directors expect that it will make an increased contribution during the current year".
Unfortunately this expectation was not to be realised. "The Statist" magazine, (16th July 1965), pages 196-197, gave an encapsulation of the AGM of 1965:
"Jennings Musical Industries has hit the headlines in recent weeks with news of export orders from the US for impressive quantities of the beat guitars in which it specialises. But it is doubtful whether these will be sufficient to enable it to offset the waning beat boom.
"It is a subsiduary of Royston Industries and the Royston Chairman, Mr Eric Summer, says in his annual statement just published 'we do not forsee that the company will increase its contribution to the profit of the group in the current year'".
Other, and larger parts of the group, are however steaming ahead.
The waning of the "beat boom" was current talk at the time. George Melly (look him up) when asked for his view said, not entirely seriously, that Skiffle would probably make a come back.
The order from the US (reported by "The Economist" and other sources) was in fact the second, the second large one at any rate, the first being the "Million Dollar" deal (£534,000) of late August 1964. The value of the second order was generally not specified in the press in terms of dollars or pounds, but said to be equivalent to four month's output for JMI.
5th September (2)
The Beatles, Stockholm, Kungliga Tennishallen, 26th October, 1963 - a detail from a photo showing the backs of the band's AC30s - John's on the left, Paul's Super Twin amplifier section down by the drums, and George's at right. The Twins were issued in the summer of '63, the Super Twin amplifier slightly later on. All had back panel top boost controls. As to the serial numbers, that's for another day.
Detail of a picture from the "Nordiska Museet".
For the time being, simply as a note to the picture, it is interesting to see that John's cabinet had square edges but a rounded back board. George's cabinet had rounded corners and rounded boards.
John's amp - the cabinet's upper corner is square, but the board is rounded.
George's amp - both cabinet and boards have rounded corners.
Thanks to Simon, pictures now added of serial number 8474N, probably from the third quarter of 1963 (NOT 1964 as wrongly put earlier), its cabinet reduced to the upper amplifier compartment (at some point before 1976).
Below, the cover of an EP released by "The Eagles" in France in late 1962 or early 1963. The film "Some People" was first released in the United Kingdom in July 1962.
The group is pictured with three beige AC30s - two Twins and a Super Twin. Note the position of the "BASS" runner on the Super Twin amplifier section - directly beneath the "VOX" logo. The runner is to be found in this position on a smallish number of other amps too. The normal place however is lower right on the front grille cloth.
An initial note on Jennings organ amplifiers. In 2015 a couple of chassis came up for sale accompanied by a short description from the seller stating that they had come from JMI organs. Thanks to Glen Lambert, who examined photographs of their circuits, it seems that one - the one below - conforms to the "30 Watt Amplifier" circuit designed by Derek Underdown in the 1950s - i.e. before Dick Denney joined the company.
As Jim Elyea has noted, the basic design of the power section was taken up by Underdown and Denney when they came to work up the Vox AC2/30 in the late summer of 1957.
It is hard to be precise about the date of the organ chassis - possibly very early 1960s. The organ amplifiers went on long after the AC2/30 had gone its way.
Derek's notes on the "30 Watt Amplifier" survive in one of his work-books, a couple of pages from which were posted on the JMI amplifiers FB page by Derek's daughter. It was Glen Lambert again who spotted the connection.
A detail from the circuit diagram for the "30 Watt Amplifier" designed by Derek Underdown.
Note the large diode fixed to the chassis top right, and the lamp on the circuit board to help regulate the bias voltage. A lamp was used again by JMI of course in the bias circuit of Vox AC50s.
The two chassis together. Both have Haddon transformers and identical modes of construction.
Thanks to Marc, pictures of the Celestion blues from the cabinet of AC30/6 serial number 4478, which turned up in Mold, Flintshire (North Wales) recently - black panel, circuit predating the list of changes introduced in May 1961.
Both speakers have the date code: "15EF" = 15th May 1961, so the amp, as a whole, cannot have been ready for sale before that point. The chassis, now separated from its original cab, is likely to have been assembled a while before May though.
A detail of the cone code of one of the drivers: "RIC 1 UJ"
Just to signal, three more AC30s with serial numbers in the 11000s registered on this page: 11800, 11873. and 11874. Thanks to John for pics and info. on 11873. Further pics of 11874 to come.
In reference to the perspex AC30s produced by JMI, a perspex solid state Vox Super Beatle produced by Thomas in the USA for promotional purposes, c. 1966. JMI knew better than to produce a perspex AC80/100, however.
Owned at one time by Mitch Colby. Both amp and cab have a diamond lattice in or impressed on the perspex.
Some more pics of AC30/6 serial number 4478 N, the yellow cast of the original photos reduced where possible. Assembled at the Vox Works (115 Dartford Road). The remains of beige cloth underlies the thick vinyl wrap. One of the original Hunts capacitors has the date code "WNY" = 17th week of 1960. The WIMA Tropydurs in the preamp were replaced in the mid sixties with Mustard caps (date codes of 1964 and 1965). It will be interesting to see 4478 when it resurfaces for sale again (as it certainly will).
In view, replacement Mullard mustard caps from 1964 and the original Hunts capacitor, date code "WNY" = 17th week of 1960. This is of course simply the week in which the capacitor was made at the Hunts Works in Earlsfield (South London), not the date of manufacture of the amp.
AC30 serial number 4478 came up for sale recently. Black panel, probably late 1960, certainly the pre-list-of-changes circuit (pre May 1961). Further pics to follow.
Working on the Vox Supreme (solid state amplifiers) website at the mo., trying to get some of the older pages into better order. The site's updates page is here.
Excerpts from the JMI pricelist of April 1967 can be found below, July 17th (3). Only two valve amps - the AC30 and AC50 - were illustrated in the catalogue of 1967 (two versions) and autumn 1968, this last reprinted by the new company, "Vox Sound Equipment Limited".
In the JMI catalogue of 1966, the AC30 appears twice: once, complete, in a "group shot"; and a chassis and footswitch alongside an AC100 chassis.
On an only slightly related note, it seems that on certain chassis assembled by Westrex a number was added by hand - examples below of three different amps with "165". On another, "130" occurs, apparently written by the same person.
It is not clear at present what these numbers signify.
An AC80/100 from the third quarter of 1964 (serial number plate lacking).
AC30 Super Twin, serial number 3021.
AC30 Super Twin, serial number 3863.
11th August (2)
Below, a picture taken at one of the heats in the "Battle of the Bands" competition devised by Marv Kaiser to promote Vox in the USA. The competition ran from late March to 16th April, 1965, the finale being at the Hollywood Palladium in Los Angeles. Captain Beefheart won.
This picture was taken at the San Mateo County Fairground, probably in early April '65. At right, a new slope-sided AC30 Super Twin Reverb. For further details of the competition, see this page on the Vox AC100 website.
In another picture of this heat, one can see an AC50 Foundation Bass set at left, and the full width of the small-box AC50 or possibly AC100 on top of the AC50 Super Twin speaker cabinet.
A new page has been set up on AC30 Super Twins, 1965-1967. Some additions as ever to follow. The serial numbers caught in the photograph taken in April 1967 have been noted. In terms of survivals, there are some very "near misses" - for instance ser. no. 3617 survives, only two numbers away from 3615 in the photograph.
Presuambly the amps caught in the photo with Terry Dowson are exceptions, most being sent into the world not *too* long after manufacture. This is certainly the case of ser. no. 4831 immediately below. But one must resist turning assumptions into hard and fast "rules".
10th August (2)
Just to give an idea of how scatter-gun the processes of storage, sales and despatch could be, a picture (below) of the documentation that survives with Super Twin serial number 4831, sold on 8th January 1966. The amp is over 500 serial numbers higher than the latest visible in the photo in the previous entry, yet was in the hands of its new owner well over a year before serial number 4321 was despatched from Erith.
Below, a composite of the Super Twins waiting to go out from the Vox Works, Erith, late April 1967 - details from the photo at the foot of yesterday's entry.
The serial numbers - and they are serial numbers, not chassis numbers - extend in no apparent order from 03239 to 04321. Why such an assortment?
What happened is that when amplifiers were complete:
1) Serial number plates were added, and the numbers written down *in order* in Jack Jennings's registers.
2) The amps were then given covers, boxed, and the model and serial number written on the outside.
3) The boxes were put in store. New boxes coming into store would naturally make some of the boxes already there inaccessible.
4) When someone said to the storeman "nine Super Twins needed for despatch", the most accessible ones would have to be taken first.
5) The date of despatch and destination of the amplifiers would be noted down against the entry for the serial number in Jack Jennings's register.
At no point can one really assume that amplifiers were stored in order of completion, or in serial number order (as marked on the boxes).
AC30 Super Twin serial number 3349, probably produced in late 1964, still has a rectangular box, hand-stamped plate, and brown grille cloth (No to this last, the grille cloth has been replaced). It seems that JMI massively over-produced AC30s in 1964 (and 1965).
AC30 Super Twin boxes awaiting despatch in the Vox Works, Erith, late April 1967 - composite picture.
Some grabs below from film shot in the Vox works in 1965, segments incorporated in the BBC4 documentary "Vox Pop: How Dartford powered the British Beat Boom" (2012).
The brief foray into the Despatch store was either shot at 115 Dartford Road, where other sections were certainly filmed, or in the new factory building at Erith, which Vox shared with Burndept Electronics from early '65.
In the first picture, one can see organs on a trolley, and at left and in the background, AC30 Super Twin amplifier sections. What else could they be? AC50s? They seem a little too long for an AC50.
In the other pictures, very probably AC30 Twins (or Super Twin speaker cabs) boxed up.
Below, Terry Dowson on the Despatch floor at the Burndept / Vox Works, Erith, with a consignment of new solid state amps in April 1967. Also visible, AC30 Super Twin amplifier sections, serial numbers (in order): 03239, 03307, 03389, 03612, 03615, 03642, 036x1, 04056 and 04321.
The numbers of the AC30s Super Reverb Twins are partly obscured, but one certainly begins: 05xxx."
A little off piste, a flyer for the Vox Vintage Calendar released in Germany in 2000 and featuring some of the guitars amassed by Wolfgang Seidel (Wolfie) and a selection of amps belonging to the hire company, Reisz Promotions. Both collections are now dispersed.
Although some of the dates assigned to the guitars and amps pictured are slightly wide of the mark, details of serial numbers and so on are given throughout. Centre top, the brown-fronted AC30 Super Twin is serial number 2568 N.
6th August (2)
Added to the entry on Allan Billington, 30th July below, a picture of his label on a Farfisa organ. Thanks to Simon for the pic.
The page on AC30s with serial numbers in the 15000s has been set up here, further additions to be made shortly.
Coming soon, some new info on early Jennings organ amplifiers, in particular the "30W Amplifier" devised by Derek Underdown in the mid 1950s. Parts of the circuit were used as the basis for Dick and Derek's AC2/30.
A note on AC30 dates - the distinction between the date of manufacture of the chassis, and the point at which an amplifier was ready for sale.
The numbers stamped on chassis by Burndept are no help. Batches of chassis were made, stamped, and stored in *no particular order*. They were then taken from store, again in no particular order, for assembly on the work benches.
Date of manufacture of chassis: this for the most part is a matter of determining the latest component date code stamped on capacitors, potentiometers, and so on.
When electronic assembly was complete, chassis were put to one side to await fitting into a cabinet. Finished chassis were stacked in no particular order. Remember that from Spring 1961 the chassis made by Westrex were transported to Dartford from North London, and from autumn 1962, chassis made by Burndept transported from Erith.
Date of final assembly: no matter what anyone says, in most cases this is just a reasoned or semi-reasoned guess. As a general rule, speaker date codes are the best (though hardly infallible) guide. Serial number plates were stamped, added to cabinets, and the numbers recorded by Jack Jennings in his registers when the amplifier was complete, that is to say, ready for sale.
Chassis are therefore only one element in the process. Serial number 9998 might for instance contain a chassis that was made weeks after the chassis assigned to serial number 9999.
Often it is only possible to say when chassis were made. The point at which a completed AC30 was ready for sale is an entirely different matter. Be extremely cautious of lists that purport to match up years, months, and serial numbers. What *precisely* are the dates based on?