Vox AC30 website updates

May 2024

31st May

Some new/updated entries added to the page on early Vox AC4s (1962 to summer 1963). Thanks to Mark for pictures of serial number 2927.

30th May

Below, the plate of an early Dallas Arbiter AC30, number 61 (1061), ready for sale in August 1974 (7408). The latest visible date code in the preamp is a Plessey capacitor, 21st week of 1974. The plate itself is an old "Vox Sound Limited" plate (from late 1972 / early 1973), its central section adjusted by Dallas.

The last of the plates used by "Vox Sound Limited" as it stood in 1972 can be seen .

28th May

A page has now been kicked off on , its chassis produced under contract by Westrex for JMI in the last quarter of 1964.

Detail of the serial number plate.

28th May

Thanks to James, a set of pictures coming of Domino Super Reverb Twin serial number 2506, produced in the last quarter of 1964, still in superb condition.

Detail of the preamp of Vox Domino SRT serial number 2506

27th May

Picking up from yesterday's entry, a couple of AC30 Super Twin speaker cabinets from mid 1964 with the same initials (or cipher) in chalk - possibly "EM".

AC30 Super Twin serial number 12333.

Speaker cabinet now paired with AC30 Super Twin serial number 9394. The cabinet is around a year later than the amp.

26th May

Chalk marks inside speaker cabinets. For the most part these fall into two main categories: (1) numbers, (2) symbols/ciphers, initials, names.

(1) Numbers. These were often supplied (by the cabinet maker) simply for administrative purposes - to record the number of the cab in a batch; sometimes as a means of ensuring that back-boards could be matched with the main case. Holes were drilled by hand and positioning could therefore vary - i.e. the screw holes in the boards of one cab do not always match up with the holes of another cab without adjustment.

AC30 Twin serial number in the low 8000s; serial number 8973.

(2) Symbols/ciphers, initials, first names. These are generally the "signatures" of the ladies (normally ladies) who finished the cabinets, adding grille cloth, handles, connectors, and so. It is unusual to find first names before mid 1964. May was particularly busy with cabinets (across the range of Vox amps) in 1966 and 1967.

More on the cabinetry and related matters to come.

ALICE - AC30 serial number 15235, mid 1964; AC30 Super Reverb Twin serial number 4313, mid 1965.

"FW" chalked in AC30 Super Twin serial number 5002 (early 1962) and in an AC10 Throwback (late 1961/early 1962).

AC30 serial number 8775, late summer 1963.

"GH" chalked in AC30 Super Reverb Twin serial number 8057, mid 1963; and in the 2x15" speaker cabinet accompanying AC100 serial number 177, mid 1964.

25th May

Thanks to Marc, an interesting serial number plate, possibly a factory re-stamp - 9950 originally, then 17950 T.

The chassis (number 05557) currently in the cabinet is likely to have been taken (some time ago) from another AC30. Further details to follow.

23rd May

A page has now been started on the - serial number 35.

22nd May

Thanks again to Steve, a shot of a Jennings Organ Service Manual from 1956, probably as supplied to dealers. Known service data folders issued to and compiled for Jennings engineers were of a different type.

The second image is of a JMI folder produced for dealers in late 1965 / early 1966.

The folder measures 13" x 8 1/2".

21st May

Thanks to Steve, a shot of a superb Jennings Model C organ from 1956, serial number 35. More to come shortly.

Jennings Model C organ.

20th May

Gil Lucas of The Migil Five with a late "square lid" Continental - roller switches on the front apron, grey vinyl, silver string inset in the cabinet at front, white piping on the lid, no provision for a music stand. Still from "Swinging UK", filmed in mid 1964.

Gil Lucas of The Migil Five, mid 1964. Pic. from Getty Images.

19th May

Below, a short illustrated list of a number of elements derived by Jennings - probably directly - from Meazzi:

- The double latching form of the Meazzi Echomatic's case (latched front and top) became the form used by Jennings in 1963 for the Vox Domino and Long and Short Tom echo units.

Mark 2 Vox Domino Echo all latched up.

- Geloso XLR sockets (as on the Echomatic) fitted by Jennings to certain guitars and AC30 Super Twins (I and II) through to 1963 - .

Geloso sockets, AC30 Super Twin II serial number 5002.

- Tilt-back stands for column speakers, devised by Meazzi for the Factotum, c. 1960, advertised in the UK by Selmer in the autumn of 1962 - on the Vox AC100 website. In the early 1960s both Selmer and Jennings had copies of the circuit diagram for the Factotum.

Factotum set, Meazzi catalogue, second half of 1960.

- The name "Transonic", applied by Meazzi in 1960 to a guitar with built-in transistorised amplifier; adopted in 1962 by Jennings for its futuristic amplifier "installation" (also transistorised) - .

Transonic guitar, Meazzi catalogue, second half of 1960.

18th May

A copy of the Watkins circuit diagram for the Mark 2 Copicat, July 1961. The circuit was used by Jennings in 1963 as the basis for its Vox Domino Echo.

Watkins sheet for the Copicat Echo Unit, Mark 2.

17th May

In March 1959, Jennings applied to the old Patent Office for a Trade Mark for the name "Framez" in the United Kingdom - presumably with the agreement of Meazzi. In November the application was granted. In effect, the grant made Jennings sole distributor in the UK of any musical item labelled "Framez", and prevented or at least provided the means to stop competitors (Rose-Morris, say) importing and selling an Echomatic echo unit or Framez guitar sourced from one of Meazzi's dealers in Italy.

How soon after March 1959 Jennings had started selling items supplied by Meazzi is unknown at present. But the deal was evidently made then rather than closer in time to the earliest adverts (autumn 1959).

That the application for the Trade Mark was successful ties in (albeit loosely) with the Jennings claim (see the entry below, 10th May) to have "... pioneered the introduction of echo and reverberation in the United Kingdom".

16th May

A quick detail from a Meazzi catalogue issued in Italy for the second half of 1960 (2nd semester of 1960): the portable Ecomatic unit with "Framez" logo. The illustration is likely to have been out of date (relative to production) at the time of publication, however. The new version of the Ecomatic is likely to have been available in Spring 1960. Relevant material is being assembled .

Products offered by Meazzi proved to be a substantial influence on Jennings in the early 1960s - more to come.

The Framez "Ecomatic". Jennings marketed the units as the "Vox Echo" though on its circuit diagrams gave "Echomatic" as the name.

15th May

A new page has been started on AC1/15s and AC/30s . Three amps are currently known, without doubt there will originally have been more.

Detail of JMI circuit diagram OA/030 for the single-speaker AC/30. The connection points leading to the components in Vibravox can number 3 are highlighted for convenience. More to come on Vibravox.

14th May

JMI's "Theory of Operation" booklet for the Vox Continental and Super Continental organs .

13th May

Published in December 1960, is this the earliest dated instance of an AC15 or single speaker AC/30 with its "VOX" logo on the left-hand side of the front?

Printed in December 1960.

12th May

Picking up from yesterday's entry, a detail of the five-pin plug and socket arrangement for the Vibravox on the chassis of AC/30 serial number 4072 (early Spring 1960). Plug and socket were Radiospares components, part of its "Alldry" series, intended principally for batteries though used in practice for many other applications, as here.

The connections and purpose of the socketed wires - red, purple, green yellow, and black - can be followed on JMI circuit diagram OS/001.

Paxolin board and socket (without zinc "boot").

Plug with zinc "boot".

As Glen Lambert kindly pointed out, plug and socket are likely to have been provided to enable a Vox piano vibrato control unit to be connected as required. The amps fitted out in this way must to some extent have been "special" orders, though probably not, as it turns out, particularly uncommon. The AC1/15 pictured below is one example (the staggered arrangement of its Vibravox cans a giveaway). A further AC/30, serial number unknown, can be seen at the . It may be that Jennings assembled amps of this kind in small runs (as opposed to waiting for orders to come in).

Vibravox cans, made in batches in advance of production, could simply be wired in as needed, no modification required.

11th May

Below, a detail from an old shot of an AC1/15 from early 1959:

AC1/15 chassis, with its Audiom 60 speaker.

The staggered arrangement of cans on the upper chassis suggests that its Vibravox circuit (concealed in the cans) could be unplugged and plugged back in as required. This functionality was certainly built into certain single-speaker AC/30s later on (two survive from 1960).

Detail of AC30 serial number 4072, early Spring 1960.

The option of plugging and unplugging the third can allowed the Vox piano control unit to be connected to the amplifier. A short page on the control unit . More to come shortly.

10th May

A detail from the JMI "Choice of the Stars" catalogue, late 1962 / 1963. The first line of its short text - "Jennings pioneered the introduction of echo and reverberation in the United Kingdom" - may well be true.

The Watkins (WEM) Copicat is highly unlikely to have been available before early 1960 (in spite of what Charlie Watkins sometimes said about 1958 over the years). There is a good overview of the different versions and models of Copicat .

"Choice of the Stars" catalogue, late 1962 / early 1963. The "Cliff Richard" Reverb unit was first promoted in Spring 1962.

9th May

Early October 1959, the first JMI advert for a new range of Italian guitars. These as it turns out were made by Wandre in southern Italy and distributed in northern Italy and Europe by Meazzi, often (though not always) under its trade name "Framez".

It is not clear at the moment whether Tom Jennings's order for guitars followed his order for echo units, signalled as being available from JMI in September, or whether everything was ordered at one go and the shipping or preparation of the guitars simply took longer.

Quite how Tom came to take on equipment distributed/offered by Meazzi in the first instance is perhaps the question. The "British Musical Instrument Industries" did not host any trade shows between 1959 and 1961, a source of major dissatisfaction to many companies. Presumably the echo units and guitars were not purchased by JMI "sight unseen".

10th October, 1959.

8th May

A thumbnail for the time being of OOS/032, the Jennings sheet for the "Model J" Echomatic. Known surviving copies are undated. It is worth stressing again that these diagrams are not in the main "bludeprints" or "build sheets". They were produced for service engineers.

As we have it, the circuit was drawn out either by someone in Milan where Meazzi was based and where the Echos were made (though not actually by Meazzi) or by someone who had grown up in Italy. The numbers "1" and "7" for instance are written in continental form throughout, the former with a pronounced downward tick from its top, the latter with a cross-bar through its upright. Original redaction in Italy seems certain though.

A 10 x 8" sheet.

Also to signal in relation to the Model No. 2 Echomatic, offered by Jennings from later 1960 through to early 1963, that "Framez", the name often found on these machines, is simply a contraction of "Fratelli Meazzi", the Meazzi Brothers. "Framez" in other words is simply a trade name.

Meazzi and Framez also come into focus in relation to guitars offered by Jennings in late 1959 - to be taken up briefly in a coming post.

Framez = Fratelli Meazzi (Meazzi Brothers).

7th May (2)

Breaking from the run of entries on echo units, a great shot - thanks to Steve - of the underside of a Vibravox can potted with Araldite in an early AC1/15 (early 1959). The page on has been updated with some new entries and the prefatory section on transformers expanded and slightly rearranged.

The colours of the wires emerging from the can are registered in JMI circuit diagram OS/001. Cans were common to four main applications: the free-standing Vibravox unit, AC1/15, AC2/30, or AC/30 - in other words there was no specific set for the AC1/15. Batches were probably made up in advance of production runs and taken from store when needed.

Detail of a Vibravox can potted with Araldite.

7th May

The promotion by Jennings of the three-input Echomatic Model no. 2 seems to have come to an end in early 1963, final appearance in a pricelist, 9th December, 1962; final instance of a published image, January 1963:

9th December, 1962: "Echo units 3 inputs". No further mention is made of the units in pricelists published later in the month.

January 1963.

6th May (2)

A couple of adverts for the "Model J" (Jennings) Meazzi Echomatic from March 1960 that are probably not well known, especially to Shadows and Shadows-Meazzi fans on the continent, some of whom seem admirably active in their interest.

Two units, both covered in dark vinyl (one seemingly black), were evidently photographed, one having a badge for instance, the other not. It is too early to say whether the white piping is the earliest to appear on an item supplied by Jennings. Larger versions of these images will be posted shortly.

March 1960, detail from a full-page JMI advert (which encompasses a spread of other items).

March 1960, image accompanied by a short description of the unit. Dimensions and weight are given, the full text of the blurb (supplied by JMI) to be posted in due course.

The advert above, published in a trade magazine, appears in a section entitled "What's New", though the unit was hardly new to Jennings at this time. It is possible however that the "newness" lay in a move to a revised type of Echomatic - the so-called "Model J" Type 1B, a modern designation, not entirely satisfactory in some respects, but there we are. Type 1B it is for the time being. As for the image, Jennings could be slow at times to update illustrations of its products.

Type 1A: - the units conventionally depicted by Jennings (from September 1959) in its adverts. Normally a white PVC strap handle, three small control knobs on the front panel (as above), black vinyl.

Type 1B: - as issued to The Shadows (see the pictures in the previous entry) and at least two other bands. A large black knob provided for the adjustment of "Effects" (Reverb), and a two-tone vinyl scheme among other changes. Further details to come.

The page on will be expanded and updated further in the coming days.

6th May

Just to illustrate in passing the use by The Shadows of a "Model J" two-input Meazzi echo (Echomatic) unit:

March 1960, Cliff Richard Show, ATV. Other instances will be documented on a coming page.

September 1960.

5th May

A thumbnail - for the time being - of OOS/035 for the Echomatic No. 2, the original circuit drawn in May 1960, and traced (ie. rendered in the form in which we have it) in July 1963 - presumably for service engineers. Component values are printed rather than written by hand. OS/030, for the single-speaker AC30, was also traced on 7th July 1963 and rendered in the same way. The name of the person who prepared these sheets is unknown at present. Note that this later version of OOS/035 contains various anomalies.

As for "purpose", remember that for the most part the small JMI circuit diagrams (10 x 8" and 13 x 8") were neither "blueprints" nor "build" sheets. They were drawn up after the event as guides for service engineers and repairmen. A number contain errors (sometimes pretty substantial ones); and batches of amps were often made in ways that do not conform wholly to any sheet issued publicly by Jennings.

A larger copy of the diagram will be provided soon, along with diagrams for other echo units designed or sold by JMI.

A small whole of OOS/035 (a 10 x 8" sheet in this form) for the Echomatic Model No. 2 from a set of diagrams assembled by or for a JMI engineer.

4th May

Some updates and corrections to the general overview page on . To be added shortly, copies of the original circuit diagrams from a set assembled by or for a JMI engineer.

A shot of a "Model No. 2" Echomatic belonging to a local Essex band, late 1961.

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