Vox AC80/100 (early AC100) serial number 173

VOX AC100 - UPDATES AND NEW INFO

2023

31st December

Just to add in relation to the JEI Echo, its dimensions are (case only, excluding protrusion of feet and handle): 13 3/4" wide, 6 3/8" tall, 9 3/4" deep - in other words, around an inch larger in all three dimensions than the latching top (and front) case of the Vox Domino Echo of 1964. The latter was of course valve rather than transistor.

29th December

Some pictures of JEI Echo unit number 1047, probably late 1974 / early 1975. The circuit board is designated "pc 176 i.c.", "i.c." standing for integrated circuit. Component date codes, insofar as any can be seen on the tightly packed PCB, are of 1973.

Mains transformer and motor at left; tensioning arm at right.

The solder points of the integrated circuit chip.

15th December

To note for the time being that serial number 836 has recently come to light in the USA. The chassis appears to have a heat shield around the EL34s, though, first seen normally on the chassis of amps with numbers in the 1100s. There are no pictures of the electronics at present. Thanks to Chris for signalling the amp's existence.

11th December

Featured on all recordings by "The Manatees" from 2016, Jennings AC40 serial number 1230, probably produced (ready for sale) in early 1972. Thanks to Tyler Bloor for the pictures. A couple more pics can be seen on this page.

JEI AC40 serial number 1230.

9th December

A superb AC100 speaker cabinet recemtly come to light: trolley with basket top, second generation/format wiring, probably complete in all respects early in 1965, still in the UK. Further pictures . Thanks to the owner for the pictures.

6th December

Thanks to Nick, the note published in the American music press in March 1968 of the formation of Tom Jennings's new company - "Jennings Electronic Developments" - following his dismissal from JMI.

The page on the events of 1967 and 1968 .

March 1968.

5th December

A new page has now been set up for the illustrated in the entries below. Further pics to be added in due course.

4th December

A couple of shots of the power section of the MC100/4, electrolytics evidently replaced a few years ago. The bias network differs in a couple of respects from the network in the other MC100/4 with a discrete bias board.

The rectangular opening in the rear lip is for the bolt attaching the section to the metal case.

The date code on the Mullard mustards is "C4N" = third quarter of 1964.

3rd December

The rear panel of the MC100/4 - standard terminal block (from factory) for speaker connections rather than the Belling Lee L1469 strips used on these amps from Spring 1965. See the entries for 12th and 20th January at the foot of this page.

Rear panel.

Rear of the front panel showing the lines from the output transformer to the terminal block. Orange grommets are always a good sign of assembly by Triumph.

The amp below, similar in date to the one above and also in the UK, was evidently prepared in much the same way:

2nd December

A note on the transformers used in the Vox MC100 amplifiers. These were massive open-frame units, probably made for JMI by Drake. The lamination stack of the mains unit for the MC100/4 measures: 5 1/4" x 4 1/4" x 3". The output transformer's stack measures: 5 1/4" x 4 1/4" x 2".

The designations on paper slips are "D45M/1" (mains) and "D55 O/1" (output). The choke is unmarked.

Upper chassis, power section.

Mains transformer sticker.

Output transformer sticker

1st December

Coming shortly, a set of pictures of a further early flat-fronted MC100/4 recently come to light, one of four currently known.

The latest component date codes found so far: Mullard mustard capacitors in both preamp and power section "C4N" = third quarter of 1964. In company with another early example, a number of the bias components are on a discrete tag-board. During the course of 1965 a single board was introduced for the main power circuitry.

Assembled by Triumph Electronics for JMI under contract. The carry handles are probably early additions, the DIN socket on the front later. The amp was until recently still in use in Germany.

29th November

It is worth recording that the advert below, often reproduced without much comment, is one of the first, if not the first, full-page promotion placed by Thomas Organ for Vox in the American music trade press - February 1965. Dealers were the intended audience. The chance to cash in was the message.

It took Thomas a good while to break away from its "British Invasion" theme and branch out into something more interesting. From late 1966 / early 1967 the company really began to find its feet though, producing innovative and colourful promotional material based around American bands.

February 1965. The photographs used by Thomas in its early promotions were often a year old or more.

28th November

American music press, October 1964 - a nice shot of Tom and Joe Benaron, perspex AC30 and Continental in front, Russell Hotel Trade Fair, late August 1964. The official "handshake" photo for the "Million Dollar Deal" had already been published in the British music press in September.

October 1964

The deal was not in actual fact to distribute "all" Vox products, simply an agreed selection. More on Vox in the USA in 1964 and early 1965 to follow soon.

27th November

It turns out that the "Jennings News" brochure was printed in two versions - one in late 1969, the other in late 1970. Front page and main content are identical. The back pages are different however.

The version issued in 1969 ends with electronic percussion and an advert for the Jennings repair service. The version rejigged in 1970 ends with the AC40 - displayed for the first time in the UK at the Russell Hotel Trade Fair - and the Tympano units, no more Tamborino.

Back page of the 1969 printing.

Back page of the 1970 printing.

23rd November

Thanks to James, a couple of provisional pictures of "Jennings Electronic Industries" Echo unit serial number 147, late 1974 or early 1975, recently sold, further shots to come. Two other examples are currently known - numbers 145 and 148 - .

22nd November

April 1964, the first full-page advert seeking a country-wide distributor placed by Jennings in the American music press. A small image of this page was posted years ago on one of the bulletin boards (now long gone - probably the Plexi Palace site) - good now to have the source and date of this printing. It is likely that there were at least two other printings in other journals.

April 1964.

21st November

March 1964: the beginning of Tom Jennings's search for a country-wide distributor for Vox in the USA - a sort of direct/indirect report, published in the American music press along with the "Jumping Beatles" advert below.

American music press, March 1964.

American music press, March 1964. The success in the USA was of course the appearances on the Ed Sullivan show and the concert in Washington.

The various versions of the advert published in the UK can be found .

18th November

Thanks to Nick, a detail from a full-page advert placed by Jennings in a spread of American music trade magazines to coincide with the . The Continental at this time was the big thing - a version of the ad printed in various British and American journals a few months earlier gave the specifications in some detail.

The American material from 1963 relating to the Continental will be posted in its entirety on the Vox AC30 website in due course.

5th November

The amplifier section box of AC100 serial 231 survives in the USA, the chassis - either copper or black panel - presumably long gone. That the grille cloth on the box is black suggests that the amplifier was issued as part of a SDL set. There are at present no details bearing upon the question of when the box (and/or amp) found its way to America however.

AC100 serial number 231 (box only).

1st November

The page on the has been updated with further examples. Thanks to James for pictures of serial number 986, close to the end of the run. The highest number encountered so far is serial number 990, made ready for sale in the summer of 1974 - old stock finally finding its way into the world.

23rd October

September 1962, a detail from a Selmer advert for the Meazzi Factotum, a sort of multi-purpose amplifier (with echo and reverb) and speaker set. The Factotum was well known to Jennings, which also imported units for sale - one offered by Musicland in 1963, circuit diagram copied in August 1960 (for factory use).

The thing of note in the advert though is the tilt-back column speakers - a good nine months before JMI began work on its Line Source 40 columns. The Meazzi/Selmer speakers were clearly the inspiration. The hand-wheel assembly took a little while to work out however - .

September 1962.

15th October

Below, a shot of the plate of AC100 serial number 1848, which survives in Spain. No further details at present. Thanks to Alfredo for the pic.

1st October

Just to note that AC100 serial number 2025 and its 2x15" cabinet is currently for sale in the Netherlands. Pics to follow. Thanks to Eric for the info.

23rd September

Thin-edged AC80/100s with black grille cloth (from factory). These were always paired with speaker cabinets with black grille cloth. At present four, perhaps five, are known from photos. The amps issued: to John and George of The Beatles in late July 1964; to Paul McCartney in early October; to Brian Jones in mid October for the Stones' brief European tour; and (possibly) to the Hollies in mid September 1964 (for use with a large box AC50 cabinet).

Perhaps only around half a dozen made in total? JMI AC100 Super de Luxe speaker cabinets generally went out on loan in late 1964 with AC80/100s in thick edged boxes. These naturally had black cloth too.

The cloth on serial number 169 is likely to have been replaced later (the diamonds are too large for 1964). Another surviving amp once had black cloth, but it is not known whether this was from factory. Very probably, but no absolute proof.

Thin-edged AC80/100s with brown grille cloth were invariably used with Foundation Bass or 2 x 15" speaker cabinets also in brown.

19th September

A note on the initial batch of four AC100 Super De Luxe speaker cabinets made in early August 1964. Two of the four were issued to The Beatles and paired with the amplifier sections in thin-edged boxes that had originally been given by JMI to John and George in late July. The other two - sets with new amplifier sections - were retained by JMI for promotional purposes. Info that has come to light recently shows conclusively that the amplifier section of at least one of these promotional sets was housed in a thick-edged box with plastic corner protectors - the earliest instance for an AC100 to date. This was the AC100 Super de Luxe that JMI had photographed for its submission to the Patent Office (October 1964).

More to follow in due course. The other Super de Luxe set retained by JMI was mainly used for loans and is seen on stage at various events from mid October to December 1964. In late 1964 a new batch of AC100 Super de Luxes was produced, some again for loan and demonstration purposes, others for sale.

15th September

Also started on the page on "Musicland", a section on sheet music.

14th September

Added to the page on , the Jennings shop in Bexleyheath, pics of the envelope and return envelope of a catalogue set sent out to a prospective customer in February 1964.

Later envelopes were printed with the silhouette of the "Jumping Beatles" rather than that of "The Shadows".

12th September

August 1962, part of a double-page advert placed by Tom in the music trade press to accompany the JMI stand at the Russell Hotel Trade Fair - the "Piano-Harp", a means of reproducing the effect of a honky-tonk or "tack" piano (and other instruments) on any normal upright piano.

Jennings had been made exclusive UK distributor of the device, also of the "Piano-Hush", by "Piano Accessories Incorporated" of New York. Quite how Jennings and Piano Accessories came to link up is not known at present. It should be said however that Tom had done business with other American companies - notably Excelsior of New York - from as early as 1950.

The first formal showing by JMI of its own range in America was at the NAMM show in the summer of 1963 - see the entry below.

The "Piano-Harp" and "Piano-Hush" remained part of the Jennings catalogue through to the end of 1965. That a full page advert was taken out in 1962 tends to indicate that Tom attached more than ordinary importance to the devices and the deal.

August 1962.

An advert placed by "Piano Accessories Inc" in an American trade magazine, March 1961.

JMI pricelist, November 1965.

4th September

A couple of items relating to Tom's first major foray into the USA in the 1960s - the Jennings stand at the NAMM show in Chicago, July 1963. The first is a note of the presence of the stand in an American music trade journal - Room 966W of the Palmer House Hotel. Although listings for the show are by no means comprehensive, it is evident that Jennings was there independently at this point. The arrangement to distribute Thomas Organs (announced in August 1963) had not yet been broached or at least finalised. Close to Jennings on its corridor were V.C. Squier Company Incorporated (violins and strings) in Room 968W, and Mills Music Incorporated (music publishing) in Room 969W. Thomas had rooms 617-620 on another floor.

The page on JMI's stand at the Chicago show of 1963 .

The second piece is a note of the application by Jennings to protect the trade name "VOX" in the USA, filed in October 1963, perhaps at the suggestion of Joe Benaron, who managed Thomas. Joe attended the Russell Hotel Trade Fair in London in late August 1963.

American music trade journal, July 1963.

US Patent Office application.

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