30th September

The page on later Vox AC4s (from late 1963 on) is in the process of being updated. Thanks to Ian for pics of serial number 3089.

Thick-edged cabinets appear in the mid 3600s, corresponding closely with the advent of machine-stamped serial number plates. To give some context, thick-edged cabs for single speaker AC10s appear in the mid 4500s.

29th September

A new page on the split-front single speaker AC10 of 1961-1965 has recently been set up. As it builds, the existing page on the AC10 Twin will probably need a little tweaking.

JMI brochure from Spring 1961.

27th September

A page has now been started on JMI's use of Plessey speakers (in the Univox and G1/10).

26th September

Thanks to Steve, a shot of something not often seen - the interior of a closed back AC10 Super Reverb Twin speaker cabinet, the wiring original (note the insulated staples) up to the added terminal block. The speakers are Elac 10N/85s. In company with AC30 Super Twin cabinets, the back panel has a thick inner board of birch ply.

Whether the wiring commonly ran along the foot of AC10 SRT cabs is not known. No parallels have come to light so far where AC30 Super Twins are concerned. A similar approach was taken later on though in a batch of AC50 Super Twin cabs.

Speaker cabinet of an AC10 SRT, second half of 1964, serial number in the 1400s or 1500s.

AC50 Super Twin speaker cab, later 1966.

25th September

A page has now been started on the Celestion CT3757 speaker, for the most part bringing together material in danger of becoming too dispersed on existing pages.

One of the questions that arises - unanswerable at present - is the extent to which CT3757s and early CT530s overlapped. So far as one can make out, for third circuit AC15s T530s came first, then for the last third of 1960 and perhaps into early 1961, CT530s and CT3757s were apparently used fairly interchangeably. The picture may change as further instances come to light.

24th September (2)

To give some context to the probable date of AC1/15 serial number 3539 - the chassis AC1/15 serial number 3582 contains at least one original capacitor with date code "PH" = August 1958 for its manufacture. So perhaps a little over 100 AC15s made in 1958.

24th September

Thanks to Steve, a shot of the chassis of AC1/15 serial number 3539, probably late Spring 1958. Further pics to follow. It is likely that only the first 50 or so chassis were done in blue. Number 3682 is plain aluminium.

20th September

Recently come to light in the UK, AC1/15 serial number 3539, the second earliest first circuit AC15 currently known. The sequence began at 3500. As in the case of serial numbers 3537 and 3542, the chassis is blue. Further details coming shortly.

17th September

A super clean AC30TB - produced at the Birch-Stolec factory in Hastings (St-Leonards-on-Sea) and issued by "Vox Sound Limited" in the late Spring of 1973 - serial number 26074. The company was pretty much dead in the water financially at the time but still operating.

The speakers - Celestion alnico T2056s - have the date code "DF6" = 6th April, 1973. Thanks to Philip for the info.

AC30TB serial number 26074.

16th September

Below, an AC30/4 chassis and what may have been its original speakers, either Celestion CT3757s or just possibly very early T530s, in a later AC30 cabinet (from 1963). Note the early form pink and yellow wiring. Labels are oriented with the speaker terminals.

The cabinet has rounded corners at back. Celestion CT3757s and T530s were effectively the same speaker.

As mentioned below (first entry for 12th September), several other AC30/4s are known with such speakers. A pair also turned up some years ago in a Vox UL460 cab (as replacements for its originals). It seems highly unlikely that the five pairs in view were simply ransacked from single-speaker AC15s, the only model of Jennings amplifier fitted with this type of Celestion as standard, or at least moderately standard (serial numbers in the 4100s and 4200s).

Vox UL460 speaker cabinet with a pair of CT3757s, added in the 1980s, date codes late August and September 1960. The original speakers - Celestion T1225s - were long gone.

That certain AC30/4s (both TV Front and split-front) should also have been issued with 3757s (from factory) in late 1960 and early 1961 seems perfectly in order. Date codes are normally in the last third of 1960.

As for organs: speakers were hidden from view and, so far as we know (from photos and report), did not have special labels. Besides, the various ranges at this time were marketed not as "Vox" but "Jennings". The first "Vox" organ was the Continental.

In spite of what is sometimes asserted, JMI rarely used one type of speaker invariably for a particular model of amplifier then moved invariably to another in the late 1950s and first years of the 1960s. Nothing quite so abrupt or simplistic. Consistency only really came in during the course of 1961. For the time being, the charting of occurrences of types is key. As for Celestion 3757s in AC30/6s ...

12th September (2)

The slope-sided AC10 Super Reverb Twin, shown for the first time at the Russell Hotel Trade Fair, late August 1964. A small pic of the display can be found at the foot of the AC10 SRT "holding" page.

Although pictures of the backs of these amps are rarely shown, it is clear that at least one example has a DIN socket for its footswitch.

A DIN was also envisaged for the slope-sided AC30 SRT but so far as one can tell at present - never say never - not used during production. Below a photo submitted by JMI to the old Patent Office in late August 1964 in support of its application for the AC30 SRT, DIN socket in position.

Detail of an AC10 SRT, one evidently sold in the UK.

From a series of photos submitted to the old Patent Office by JMI, 28th August, 1964. The metal brackets supporting the amplifier section were illustrated in the "Vox: Precision in Sound" newspaper-format catalogue of September '64.

In 1966, DIN sockets were used for the more complex type of footswitch supplied with the 7-series amps, and also a little later, for the fully solid state range.

12th September

Recently sold in the USA, an AC30/4 chassis in a new cabinet, serial number plate from a later amp.

Distinctive wear along the front edge, in particular at left. One of the Hunts caps in the preamp has the date code "IAY" = 39th week 1960 for its manufacture.

Serial number plate from some later amp.

Shiny screws, nuts and washers throughout the cabinet. Non-original wiring of the speakers.

The speakers are likely either to be CT3757s or (just possibly) early T530s. Whether they are original to the chassis is unknown.

That they belong, at any rate, to a series of batches that were given labels prior to being fitted into cabinets is clear from the alignment of the "VOX" logo, the reference point (for orientation) being the speaker terminals. There are plenty of examples where AC15s are concerned. A little later on labels were aligned horizontally in the cabinet regardless of which way the terminals were pointing.

At least two other AC30/4s have such speakers (or at least are currently "accompanied" by them), one now in a cabinet from 1963 - possibly a refit by JMI. More on that soon. Just to say that it is perfectly conceivable that JMI replaced numbers of old-fashioned TV Front cabs in its time, transferring chassis and speakers to new split-front cabs.

10th September

An overview of the different types of JMI spring reverb assembly, 1962 to 1964 - simply notes for the time being.

Early portable reverb unit, beige/fawn covering. Double lines of springs joined in the middle. The white cartridges, hidden by metal shrouds, were made by ACOS.

The arrangement above was used in early assemblies fitted to AC30s and probably also to AC10 Super Twin Reverbs through to the end of 1963 (and on into 1964).

Assembly and back panel control module from an AC30.

The assemblies were normally suspended by elastic bands in a metal enclosure fixed to the underside of the slider board:

Enclosure and assembly removed from an early AC30 SRT, one of the lines of springs subsequently removed leaving the centre post.

The ACOS GP71 cartridges in the assembly of an AC30 SRT from mid 1963 (serial number in the 8000s). Thanks to Magne for the picture.

By mid/late 1964, JMI had evidently gone over to single line spring assemblies (normally formed of one or more springs linked together), presumably to save money. Below, one from an AC30 (top), the other from a Domino Super Reverb Twin or slope-sided AC10 SRT (later 1964 and early 1965).

Below, details of slope-sided AC30 SRT serial number 5031, single spring assembly under the slider board (still the conventional position):

Above, AC30 SRT serial number 5031.

Prior to the adoption of the red Sonotone cartridge in 1966 for the 7-series and fully solid state ranges of amps, one sometimes finds a black type, maker currently unknown.

Late Vox Domino SRT. Such cartridges are also found in late portable Reverb units.

9th September (2)

Also in the auction this weekend, a grey panel AC10 Super Reverb Twin from mid 1964, but spread over two lots, the amplifier section with the AC1/15 (and other things), its speaker cabinet with two AC30s and a 4x12". Total - five figures for the two lots together (presumably one buyer at work).

9th September

A well-used first circuit AC1/15, auctioned and sold this weekend past in York as part of a lot (of ex-studio equipment), the back panel probably missing, at any rate not photographed. The Celestion blue is obviously not original though had clearly been in the amp for some time.

On the front, simply to observe the logo is on the left (right is normal), and the threads defining the diamonds in the grille cloth have no colour.

8th September

From a pricelist produced by JMI in September 1964 for "Musicland", the Jennings shop in Bexleyheath (88 Broadway) - prices of the newly revamped range of Domino amps, revised possibly simply to correct a misprint. The new range was shown for the first time at the Russell Hotel Trade Fair, late August 1964.

Detail from a "Musicland" pricelist, September 1964.

7th September

Eight new entries have been added to the page on early AC10 Twins, late 1961 to 1964 - mostly for single speaker AC10s with known component date codes (useful as "markers"). A page on the AC10 Super Reverb Twin forthcoming.

6th September (2)

Thanks to Timo, pictures of AC30 Twin serial number 7443, mid 1963, have been added here. Its plate, with "VOX AMPLIFIER" at top, indicates that the series of plates with "AMPLIFIER" alone ran for only a short time in the 7400s - only 30 or so amps presumably as a temporary measure.

AC30 Twin serial number 7443.

AC30 Twin serial number 7433.

6th September

The page on the Univox in 1955 has now been started here. It should be possible to give in the near future rough estimates of the numbers of Univoxes made, model by model, in the period 1952 to 1956.

October 1955, prices just visible, Mantovani still taking pride of place.

5th September

Just to record the slightly sad breaking up of an AC30/4 from late-ish June 1961, chassis (black panel), cabinet (split front), and speakers sold separately. The dealer mistakenly thought the cab was later. In actual fact it was the original, recovered and given an American-style horizontal "VOX" logo. The date code on the original Celestion blue that remained in place (along with the original wiring) was "29EF" = 29th May 1961 - recorded on this page.

The various elements will doubtless appear again at some point in new "scenarios". Pictures of the amp as it stood when it first emerged will added to the AC30/4 page in the near future. Although the chassis had pretty well been "shotgunned" - almost wholesale replacement of certain classes of component - many of the originals had been retained (in a bag).

4th September

A page coming soon on the Univox in 1955. The use of one on the Sooty Show had been signalled in 1954 - advert of November on this page.

March 1955

3rd September

The well-known picture of Chuck Berry with an AC30TB, backstage, Manchester, 12th January, 1965. The man on the right is Mike Patto, compere on the tour. Thanks to a super high resolution image the serial number of the AC30 is now known.

At the time the amp was evidently either new or little used, the JMI tag still attached to its handle.

Old style tag with "VOX" in cursive. During the course of later 1964, a new style was introduced with "VOX" in bold upright.

2nd September

Spotted this summer (July 2024) in the USA, black panel AC30/6 serial number 4696N, sold in Doncaster in 2007 by Electro Music (picture from the 2007 auction above). Everything looked straight at that time - good honest repairs. The distinctive shadows left by stickers are still there on the front.

1st September (2)

The page signalled in the previous entry has been adjusted to take account of the lengthy cross-over in 1966 from standard "old-style" frames (with solder terminals on the frame itself) to "new-style" with a dedicated tagboard attached to the frame.

Earliest "new style" known at present = February 1966. Latest "old-style" = August 1966.

1st September

A page on Celestion T1088 speakers - the Celestion "silver" - has now been started, material on the mid 1970s (principally from early Dallas-made AC30s) to be added soon.

Date code "02FJ" = 2nd June, 1964.

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