31st May

A series of entries on the transformers used in AC30/4 and AC30/6s will be assembled here over the coming days eventually to be formed as a new page. Some preliminary and cursory remarks in the form of notes and pictures below:

It seems likely that the paper labels on Haddons, Albions and Parmekos, stuck on with sellotape, were added by JMI.

In the case of transformers for AC50s, JMI evidently dismantled specimen units from batches and detailed the internal structure on sheets. These sheets still survive (ownership known). Whether the same went on for AC30 transformers is unknown - probably so though.

HADDON - 1960 to 1963

Based in Wealdstone, Middlesex. A huge variety of transformers manufactured, some on military contract. The units made by Haddon for Vox were mains and output transformers only. To accompany these, JMI used a Radiospares choke - "L.F. Choke, Heavy Duty", printed with the early "running man" logo. The JMI part numbers were the same as those marked on Albion transformers:

Mains: OH114.

Output: OH083. Also found stamped on the cloth underside of output transformers.

The transformers of AC30/4 serial number 4347B.

Mains transformer of AC30/4 serial number 4401. One can just make out the part number on the sticker - OH114

ALBION - from late 1961

Not much is known about the company. A good deal of its business seems to have been in multi-tap tranformers for instrumentation. The JMI part numbers were the same as for Haddon:

Mains: OH114.

Output: OH083.

Choke: PE241. A Parmeko unit? Most Parmeko transformer codes (as advertised in trade journals) simply have a "P" prefix, however, not "PE".

Click as ever for larger images. Albion mains transformer, part no. OH114; output transformer OH083.

WODEN - from autumn 1962

The company was based in Bilston, near Wolverhampton. Transformers are marked with JMI part numbers (for reordering) and date codes of manufacture. The date codes are NOT the date of manufacture of the AC30. Early part numbers are:

Mains: 66309. In 1963 the designation became 66309 & J/82.

Output: 66310. In 1963 the designation became 66310 & J/83.

Choke: 66311. In 1963 the designation became 66310 & J/84.

In 1964, the transformers made for Vox by Woden were produced in a simplified (and therefore cheaper) form. The new part numbers were:

Mains: 76852.

Output: 76853.

Choke: 76854. Also used in the Vox AC100.

PARMEKO - 1964 and 1965

Based in Leicester (Vernon Street). Produced transformers for audio applications - radios and hi-fi - and instrumentation. The JMI part numbers were:

Mains: 66313.

Output: 66314.

Choke: 66429.

Note that in 1965 Vox AC100s have transformers with part numbers: 66775 and 66776, the choke being a Woden (noted above). In 1966 AC50s have: 66522; 66523 and 66524. These are simply JMI part numbers, not the designation of manufacturer.

30th May (3)

In reference to the previous entry, an advert placed by Haddon in "Electronic Engineering" magazine, February 1954:

Encapsulated transformers of the type illustrated were often used by Leak, manufacturer of high end Hi-Fi amplifiers.

Glen Lambert, on a Plexi thread of many years ago, noted that the output transformers made by Haddon for Vox AC30s had stacks with laminations in groups of five: i.e. five aligned the same way, then five aligned differently, and so on.

In other output transformers one normally finds laminations oriented differently one to the other, not in groups.

30th May (2)

Sold on ebay in 2014/2015, an amplifier said to be from a Jennings (JMI) organ - presumably, if correct, one of the console / church organs. There were six pictures, of which two are below. The others will take a bit of finding. From memory, the wiring was pretty untidy, i.e. not nearly as neat as in the guitar amps.

At any rate, one thing of interest about the units is their Haddon transformers. Haddons are also found in early AC30s. The ones below look as though they're for 50 watts. Date is uncertain, but probably later than the AC30s - perhaps 1964-ish?

Jennings produced a good number of console organs in the early to mid sixties, often with striking names: in late 1964 the "Casino", "Carousel", "Carnival" and Concerto". Further below, a page from the catalogue of early to mid 1964. Most of the organs had built-in amplifiers and speakers. JMI also distributed transistorised console organs produced by Thomas (USA).

30th May

Just to add as a note to the entry for the 28th May, below, that The Shadows' first set of AC30s had five screws along the top edge of the back board, fixing to the chassis inside. Three seems to be the norm for early black panel AC30/6s.

29th May

A nice copper panel AC30 in beige cabinet, serial number in the high 4000s or low 5000s, no further details at present. Note the black WIMA Tropydurs still in place in the preamp. A short way into production of the copper panelled amps, gold-coloured WIMA Tropyfoil (Tropyfol) were introduced.

See the entry below for 13th May (2).

Above the black WIMA Tropydurs still in place.

28th May

AC30/6 serial number 4463, normal voicing, probably produced in early 1961. Thanks to Ed for the pics. The amp is now registered here.

28th May

The page on early (1950s) AC30s has been divided in two - the AC2/30 is here; and the AC/30 of 1959-1960 is here. The latter now has a section at the foot of the page on surviving amps (to be further augmented shortly).

27th May

Some interesting details from pics taken on 18th June 1961 - The Shadows playing in Calais, a day trip planned as a double bill with Gene Vincent, though Vincent was in the end unable to appear. There's a short newsreel clip of The Shadows' performance on youtube.

The pics show the backs of the band's first set of split-front AC30/6s - smooth black vinyl, brass vents, black leather handles, black and gold circular control knobs, and the serial number plate of at least one amp on the lower back panel (rather than the upper, as is normal).

One can just see the white of the back panel top boost controls on the rear of the nearest amp (Hank Marvin's). The other amps appear to have plain backs. ** 29th May - NO! Hank's amp does not have top boost on the back panel.

26th May (2)

An illustration of changes slipped into various iterations of JMI literature. Below, one side of a fold-out brochure printed for "Musicland", effectively a second Jennings shop, in early 1961. The only amp illustrated is the AC2. Others however are listed.

Further below (third pic.), a version of the same brochure - note the AC2 again - but with a variant list of amps.

Above, the brochure for "Musicland" and detail.

The image above is a digital composite. The brochure in reality takes the same form as the "Musicland" printing. Note in this version, however, the inclusion (original) of the AC30/6 TWIN.

26th May

Some pictures will be posted shortly of AC30 serial no. 4463, a very early black panel AC30/6, probably early 1961 - thanks to Ed.

A copy of "Vintage Guitar" magazine, May 1998, containing John Teagle's piece on single-speaker AC/30 serial no. 4052, arrived in the post from the USA yesterday evening. Great reading. Fascinating to see as well the adverts placed by music shops throughout the magazine. These were the days when a couple of well-known English dealers were amassing great piles of Vox gear to ship to the States, principally California, never of course even the slightest hint of "funny business" involved.

At any rate, in the piece on the AC/30 a photo, among other things, of a JMI pricelist from mid 1960, giving the price of the single speaker AC/30 and the new TV Front twin. This marries up nicely with the prices given in "Accordion Times", May 1960.

Pricelist, no date, but doubtless mid 1960 given the correspondence with the advert placed in the "Accordion Times" below.

Detail from the advert below.

"Accordion Times", May 1960. The AC1/15 at 65 gns, the AC/30 at 79 gns. The amplifier at 100 gns is the new AC30/4 twin - see this page.

It will be necessary at some point soon to split the page on early AC30s in two: one for the AC2/30 and another for the single-speaker AC/30.

24th May

Advert placed by Sherman Clay Music in the "Daily Independent Journal" (San Rafael, California), 3rd May, 1965. The AC30 - twin 12" speakers, 60 watts (American rating) - is $520. At around the time the ad was published, Thomas Organ was in the process of re-naming the English-made amplifiers, the AC30 becoming for a time the "Viscount".

"Daily Independent Journal" (San Rafael, California), 3rd May, 1965.

19th May

Gene and the Cossacks on the cover of "Banjo, Mandolin, and Guitar" magazine, May 1964, with two AC30 Super Twins from 1962 (note the old style handles).

18th May

Footswitches - the change from the early round type to the new "egg" format seems to have taken place between serial numbers 7298 and 7862 - i.e. in the first half (and probably first third) of 1963. But one naturally has to be sure that all belongs together.

Old style round AC30 footswitch with serial number 7298, which is currently here.

New "egg" format AC30 footswitch with serial number 7862.

17th May

"Midland Beat", October 1963, "Danny King and the Royals" with an early AC/30 or AC15, and a beige Super Twin, the amplifier section at rear of stage far right in the picture:

16th May (2)

From "Banjo, Mandolin and Guitar" magazine, January 1964, a rough-print picture of the "Rinky Dinks" with a TV Front AC30:

16th May

Below, pictures from late 1960 or early 1961 of "The Tremors", a band from Clacton, Essex. In view, a TV front AC30 and black panel split-front AC30/6. The use and ownership of early AC30s by local bands is in a way far more interesting, to my mind at any rate, than endless concentration on the well-known roster of big names. True, Adam Faith and The Roulettes had some intriguing pre-production things, but there is nothing really special about The Beatles' AC30s for instance. Pictures from this page.

The guitar plugged into the Normal channel of the AC30/6.

15th May

Another possible AC2/30 sighting - Aylesbury Granada, February 1959, Cliff Richard backed by The Drifters:

Aylesbury Granada, February 1959, Cliff Richard and The Drifters. Picture from this site.

Detail, far side of stage. Note the handle.

"Accordion Times", December 1957, Jennings advert illustrating the AC2/30.

15th May

A couple of JMI adverts from the second half of 1960. The first is from "Banjo, Mandolin and Guitar" magazine, October 1960, the second from the first edition of Shirley Douglas's "Easy Guide to Rhythm and Blues for Bass Guitar". Both advertise JMI's new franchise of Fender guitars, and illustrate an AC15.

Note the "VOX" logo and the "15" in small lower left on the front of both amps. The picture used in the Shirley Douglas advert had certainly been printed before - but without a secondary logo - so the two images were probably specially mocked-up for reprinting in 1960.

Banjo, Mandolin and Guitar magazine, October 1960. "Musicland" was run by Paul Jennings, Tom's son. Only the lowest-priced amplifier (at 25 guineas) in the Vox range is mentioned.

Shirley Douglas, "Easy Guide to Rhythm and Blues for Bass". The amp quoted at 75 guineas is the single speaker AC/30.

Detail of the front of the amplifier. No AC15 is known with an emblem of this sort.

13th May (2)

Some comments on black WIMA Tropydur capacitors:

Detail from the advert further below.

In the late 1950s and 1960s Tropydurs were widely used in a variety of applications - radios, broadcast equipment, jukeboxes, and of course, by JMI in early Vox AC30/4s and AC30/6s (1960 and 1961). Very few survive in place as these capacitors had exceedingly short lives, quickly becoming leaky and unreliable.

In vintage radio circles they are sometimes known as WIMA "toffee" capacitors - see this great thread (you'll need to sign up to the forum to see some pictures).

Below, a couple of Tropydurs in place in an AC30/4, the others largely replaced in the early 1960s by grey Radiospares polyester caps.

Two WIMA Tropydurs in place at the time when the photograph was taken. The grey Radiospares capacitors replace those that had been removed.

At some point between August and October 1961, i.e. the period corresponding broadly to the change from the last black panel AC30s to the new copper panel AC30/6s, gold-coloured WIMA Tropyfoil (Tropyfol) were brought in - doubtless stipulated to the two contractors which then began to assemble increasing numbers of chassis for JMI: Burndept Electronics and Westrex.

13th May

A couple of details from the catalogue issued by Thomas Organ in the USA in late 1964 - "The Million Dollar Sound", referencing the deal made with JMI in late August 1964 for a million dollars' worth of equipment (£534,000 then). The Super Reverb Twin is in its production form. The drawing of the AC50 Super Twin is anachronistic however.

The amplifiers still have their English designations. In early 1965, however, Thomas changed the names, the AC30 with Top Boost becoming the "Viscount", the AC30 SRT the "Berkeley", and so on. In late 1965 the new names were transferred to the solid state range of amps produced in Sepulveda. Images of the catalogue as a whole can be found on the Vox AC100 website.

Material relating to Vox in the USA, 1964-1966, is being gathered together on this index page (on the Vox AC100 site).

Details from the first Vox catalogue issued in the USA, late 1964.

Just to add that the Vox AC30 parts list compiled by Thomas in 1966 is below, entry for 26th March. US material will be gathered together on a page of its own in due course.

12th May

A return soon to older AC30s. In the meantime, pictures of a single speaker AC/30 that turned up in 2015/2016 (not 2016/2017) - originally posted here, and discussed briefly (in time-honoured manner) on the old Plexi Palace site.

Below, some pictures to give a sense of it, the last showing the date code "QM" = December 1959 on the green TCC micromite capacitor. The original speaker has gone.

As so few of these amps survive *useful* generalisations about "production" are tricky. No two preamp sections are the same - they all differ. This one has a "lay-down" transformer and staggered can sections, one mounted on a small plinth (the cans contain the vibrato circuitry). In terms of overall "arrangement", there is nothing particularly special about these AC/30s from late 1959 and early 1960. Power section in bottom, preamp at top had been a standard solution among amp makers since the late 1940s.

An interesting description of serial number 4052 is given in John Teagle's piece in "Vintage Guitar" magazine, 1998.

Captions to the controls, left to right, are: "TREMULANT OFF", "VIBRATO SPEED", "VOLUME No. 1", "VOLUME No. 2", and "TONE".

11th May

A page on component date codes in AC30s has now been set up. Those printed on Hunts capacitors are the most fun by far.

9th May (2)

Below, pictures of one repro AC30/4 and one genuine early one from the early days of ebay - a reasonable number used to come up, though often in what might be termed "a right old state". The page on AC30/4, which will need updating, is here.

Just to say as a rider that reproduction AC30/4 control panels were floating around in the 2000s - so one always needs to go carefully. Original black panels also appeared from time to time, one from an AC30/6 below:

AC30/6. Sold as being original and probably the case.

The AC30/4 panels below, in spite of the faux puzzlement in the sellers' blurbs, are repros with transparent sticky back plastic over the panel to protect the surface.

Small pictures of an AC30/4 panel, black and gold. The seller's blurb - "This has been lying round the house for years, its still got the plastic on it, unused and in fantastic condition. I dont know if it is original or repro. The gold JMI lettering between jack sockets date this to 1959-1960."

Described as being "Genuine Black & Silver VOX AC30/4 front panel". The seller's blurb was: "Here I am selling a genuine JMI VOX AC30/4 front panel. Low start bid! The panel is as new, never used and still with it's original protective film".

The blurb was: "Blonde AC30........ This amp has been refurbished to the highest standard and is very loud, The cabinet has been made to the same specification of the originals from back in the day with square back, It has one of the best recovering jobs I have ever seen, The speakers are gold celestion alnicos 50w (made in England) Amp is an original 60's chassis that was a copper top ac30/6 and has been modified to the ac30/4. As you can see this amp/combo has been restored to a very high professional standard with no expense spared I have the paperwork with this that lists every job that done."

Probably the same amp as above.

Cobbled together back panels, but chassis and the rest of the box original 1960/1961.

Below, a black panel AC30/6 with relatively late pot codes - "GJ" and "HJ" = July and August 1962. Difficult to know what to make of it unless an early factory repair job:

The seller's blurb: "Description - It is hard to find AC30s that have not been swapped or changed about - I know this from personal experience.W hat follows is an honest appraisal of this AC30 I have fully serviced. Chassis wise I would date from the 62/63 period. No serial number inside or out, but the [original] pots show date codes of 1962 (GJ & HJ) however the Control Panel is Black, which might well be from an earlier period.I have had to replace the voltage selector with a slotted selectable type - Looks pretty good to me and also the Power lens is a non-standard, but these can still be obtained for a small price. - see images.From the many intricacies of changes over the years I would put this as a 1962 AC30 Amp.The amp has been totally serviced and still looks very original albeit having to have had a new output transformer, but not the usual run of the mill OT replacements. This one has been faithfully made to replicate the exact same transformer from the 1960s being wound on an original-type brown SRBP bobbin, with original pattern laminates. Output allows either 8ohm or 16ohm speaker impedances.Valvewise, all are fully tested and running true to form. I have been lambasted for saying all AC30s hum; this one does, but it is only noticeable when nothing is playing. Anyrate I have changed the 3 electolytics, which are on the preamp cathode to ground connections and the dual filter cap. I am quite happy for anyone to come visit and listen for themselves.Take a look at another learned fellow on the AC30 hum roundabout, notably the paragraph before the "Hints and Tips on Reducing AC30 Hum" at: /Vox_Myths.htm There is a foot switch that is hard wired into the circuit, which was the standard in those days - It is not original however.If you are looking for an early '60s AC30 chassis that will do the biz for many years to come, then................................ .....................................GRAB IT WHILE YOU CAN!!!! I AM MORE THAN HAPPY FOR PEOPLE TO COME AROUND TO SEE IT."

9th May

Some batches of new amps added with serial numbers in the 10000s, 11000s, and 12000s. These have not yet been captioned on the pages as being new though.

8th May (2)

Below a couple of pics of an AC30 currently on ebay in the UK, noted as being serial numnber 11452T on the auction page - possibly therefore the earliest instance of the "Treble" model that has come to light so far. The AC30 "Treble" was new in 1964. The question is however whether the circuit conforms to the schematic issued in August '64 - see this page.

Serial number 11556T, now the second earliest AC30 to have "T" on its plate, is actually a "normal" voicing.

8th May

Some pictures to show the closeness of the speakers in TV Front AC30s - serial number 4414:

The rims of the 12" Goodmans Audiom 60s are almost touching. On the Audiom 60, more on this page.

7th May (2)

Bracketing the change from hand-stamped to machine-stamped plates, serial numbers 12733 and 13016. It should be possible to close the gap further with some work.

For Super Twins the brackets at present are serial numbers 3349 and 3617.

7th May

Some updates on the pages dealing with AC30s with black panels - the AC30/4 (three new entries, two existing ones updated), and the AC30/6 (two new entries).

6th May

Some more notes on the AC30 chassis from early (not mid) 1963 signalled in the entry below for 3rd May - and a correction. The Hunts cathode bypass capacitor in the power section has the date code "ISH" = 35th week of 1962, not "HSI", which was arrived at by reading it upside (idiot mistake). The latest determinable date code in the amp is therefore 4th week of 1963 - main filter cap ("YTI").

Clearly one does not know how soon after production Hunts sent capacitors to Erith or how long it took for components newly arrived at Erith to find their way from store there to the work benches. The idea that it was only "a month or so" does not really wash. And it so much depends on what one is talking about. Woden transformers with January 1964 date codes ("AV") are still found for instance in amps produced in the middle of the year.

Three date codes visible in the power section. "TM" = December 1962 on the green Welwyn resistor; "YWI" on the 32uf Hunts capacitor = 1st week of 1963; "ISH" = 35th week of 1962.

The other thing to say is that the value of the green Welwyn wirewound cathode resistor is 82R, and its date code "TL" = November 1962:

The Welwyn date code "TL" visible in the mirror. The power rating of the resistor is marked as being 4-5 watts

82ohms was the actual value used for the cathode resistor through to mid 1963, when one of 50ohms was introduced to run the valves harder and squeeze a little more power from the circuit.

Detail from sheet OA/26, the cathode resistor marked in red.

Note added 14th June 1963 signalling the change from 80ohms (recte 82ohms) to 50ohms.

5th May

A further note on an AC30 chassis assembled for Vox by Burndept Electronics, Erith, in early (not mid) 1963. The valves fitted at factory were Brimars. The ECC83s were made at the Foots Cray works, near Sidcup; the GZ34 was produced for Brimar by Mullard.

The manufacturing date codes, as mentioned in the entry below for 3rd May, are: 3rd week of October 1962 for the GZ34, and the fifth week of September for the ECC83s.

For the Burndept factory, having a supplier close by will have been a real boon. Quite whether Westrex, the other contractor charged with assembling AC30 chassis, also fitted Brimar valves to the chassis it produced is not known at present. The Westrex factory was in North London (Dollis Hill).

Just to add that the EL84s in the chassis were replaced at some point after 1965 (the replacements have Mullard date codes for that year). The originals are likely also to have been Brimars, though.

4th May

The page on the speakers in early AC30s has been expanded and updated - more on the G12 B024 and B025, the Goodmans Audiom 60, and the Goodmans-made fan-frame driver wrongly called the "Economax" - in actual fact a low-end ceramic magnet unit with limited frequency response - extremely poor in the bass range.

As the AC15 used by John Lennon in 1962 was fitted with a pair of these Goodmans fan-frames, a mystique has subsequently grown up around "crazy rare AC15s just like John's with (so-called) Economax speakers". Excellent conversation pieces no doubt.

Further notes will be added to the page shortly.

A Goodmans fan-frame in its natural habitat - a portable speaker produced by Bell and Howell for use with its projectors.

3rd May (2)

Some notes on a chassis assembled by Burndept in early (not mid) 1963, serial number probably in the low 7000s. The cab along with speakers and serial number plate parted company in the 1980s. Pictures of the chassis to follow shortly.

Chassis number: 01518, stamped on the chassis by the output transfomer.

Woden transformers: date code "AU" = January 1963.

Potentiometers: date code "AK" = January 1963.

Hunts main filter cap (16+16uf): date code "YTI" = 4th week of 1963.

Hunts 250uf cap. (underchassis) - corrected: "ISH" = 35th week of 1962.

Hunts 32uf cap. (underchassis): "YWI" = 1st week of 1963.

Welwyn wirewound resistors: "TM" = December 1962.

Hunts preamp caps: "SWH" = 51st week of 1962.

Brimar GZ34 (Mullard made): B2J(?)3 = Blackburn Factory, 1962, 3rd week of October.

Brimar ECC83 preamp valves: 5I2/1574 = 5th week of September 1962. The second character of "5I2" is a letter "I" denoting September. 1574 is the code for ECC83.

3rd May

What's in a name? Below, the three iterations of the Vox "Vibravox" unit, designed in 1957 for accordions, though its electronics were incorporated early on in the AC2/30, AC/30 and AC30/4.

Although the design of the unit (outward appearance) was protected in British Law ("registered"), the name had in fact already been coined - from 1949 in the USA there were the Danelectro "Vibravox" amplifiers, a single speaker version much as the AC2/30 in terms of proportion, and later a twin. See the pictures below.

Evidently there was no difficulty: Vox regularly referred to the "Vibravox" in its AC30/6s through to 1964. The extent of the electronic relationship (if any) of the circuit is at present unknown.

Fingers crossed that an early Vox "Vibravox" comes to light at some point.

"Accordion Times", January 1958. First version of the Vibravox. Note the unit is "Registered", a protection of the design in law extending solely to outward appearance and cosmetics. Electronics and technical aspects were covered by other protections, which also had to be applied for - e.g. patents and so on.

"Accordion Times", March 1958. Second version.

"Accordion Times", April 1960. Third version, with black panel.

A Danelectro "Vibravox" amplifier from 1949.

The later format of the Danelectro "Vibravox" twin.

2nd May

In January 1960, Gene Vincent embarked on a tour of the UK. His first backing band - 6th to 17th January - was "The Rockets", a London group led by drummer Tony Crombie. The second was "The Beat Boys", who had been brought together by Larry Parnes to back Vincent on the second leg of the tour, 24th January to 26th February 1960.

The picture below, which has been doing the rounds with the date "Nov. 1959", is likely to be from the first leg of the tour. Joe Moretti, who played on the second leg, does not appear to be present on stage. At any rate, the shot was taken in 1960 not 1959.

On stage a Vox AC15 or AC/30 - the two amps at this point were in cabinets of the same size and finishing. Beyond it, with its logo invisible or gone, almost certainly an AC2/30.

The AC2/30 is apparently upside down, its tilt caused by a cable plugged in on its "underside" at left. Invert in your mind the illustration of the AC2/30 below.

"Accordion Times", December 1957, Jennings advert illustrating the AC2/30.

Joe Moretti with his AC15 or AC/30.

A still from a clip of Gene Vincent with the "Beat Boys" (and Joe Moretti) on Italian TV, May 1960. Moretti also used his Vox amp on Johnny Kidd and the Pirates' "Shaking All Over" later in the year.

1st May

Below, the advert for Vox placed by Nicholson's of Sydney in the Beatles Australian Tour programme, 1964. Nicholson's also advertised Vox in the Sydney Morning Herald and at various points had catalogues specially printed by JMI:

The picture of The Beatles was of course slightly out of date. On the tour, Paul had his AC80/100 and John and George AC50s.

The most recent updates are here.

Updates January, February, and March 2020.

Updates for April 2020.

Updates June 2020.