8th February

A preliminary note on JMI's repeat percussion circuit (OS/063). There were at least two versions, one early (December 1964), and one late (December 1965 with further additions/changes). The latter was intended not only for use in the Continental, but the Guitar Organ and Electronic Accordion too.

Guitar Organ, 1966. The percussion circuit occupies around two thirds of the upper section.

JMI schema.

One of the key characteristics of the two JMI circuits as we have them (early and late) is the use of a pair of interstage transformers (T1 and T2 in the schema above). It may be no coincidence that one finds the same arrangement in an early circuit employed and probably devised by Thomas Organ. Below, a thumbnail of the sheet for the Thomas BL-3 (also known as the "Coronado"). The BL-3 was one of the models displayed by Jennings for Thomas at the Russell Hotel Trade Fair in August 1964.

Thomas Organ BL-3. One finds the same divisions on the JMI sheets - Trigger, Multivibrator, Modulator.

Later on Thomas revised the circuit, omitting the transformers, so some care (in terms of reference) is needed. Note that the sheet above, part of a large collection of material given away by Thomas when it closed its offices and service centre in West London (Alperton), is said to be "Schematic No. 2". If the collection, which is in storage at the moment, preserves a copy of "No. 1", details will be posted as a future update. The repeat percussion built into certain Thomas amplifiers and the V809 pedal, it should be said, has little to do with the circuits in view.

As has been mentioned before, the other avenue for investigation goes back much further - the transistorised effects module created by JMI for its D2 Entertainment organ.

October 1959.

The Thomas connection seems the more promising at the moment, however.

5th February

December 1956, a shortlist of regional distributors of Jennings organs covering much of mainland Britain (though not at this time Wales). Rushworth's and Forsythe's were perhaps the largest (most important) of those named. Larg and Sons were principally piano dealers, though with an unusually strong voice in the trade association through to the 1960s.

December 1956.

4th February

Thanks to Mark, pictures of Super Twin serial number 8066B (amplifier section only) have been added to the main page for AC30s with numbers in the 8000s and on the page for Super Twins with BASS and VOX logos positioned together.

AC30 Super Twin serial number 8066B.

2nd February

Thanks to Bob, pictures of AC15 serial number 4755B, probably ready for sale in the third quarter of 1962, have been added here.

1st February (2)

AC30 Super Twin serial number 10253 N, what may be an early instance of an Expanded Frequency (Top Boost) chassis in its original context, i.e. still in the cabinet (and with the serial number) assigned to it by JMI. As is well known, good numbers of these chassis - some certainly having been sold "loose" in the liquidation sales of 1967 and 1968 - were at various later dates slipped into "spare" cabinets by owners and traders.

JMI it should be said also played a small part in this "redeployment", sending out a handful or two of chassis from unsold Expanded Frequency AC30s (the AC30X) as Twins in later 1964.

In terms of date codes, really the usual spread: cathode bias resistor and electrolytic caps with "UG" = July 1963; original yellow-print Mullard ECC83s with paint code "LA" = January 1964.

1st February

Music Trade Press, June 1962, the picture from this short piece posted below last week. In the final paragraph, the earliest mention that has emerged so far of the Vox Continental, which was indeed exhibited at the Trade Show in August. Evidently there was some confidence in the announcement.

June 1962. The journal corrected the statement that Williment was to head the service department (main text) in its next issue. The caption to the picture is right.

Where Cyril Windiate is concerned, the meetings at which he was to represent Jennings were of the "Electronic Organ Constructors Society", established in mid 1961, its main publication the "Electronic Organ Magazine". Copies of this magazine are extremely scarce these days. The one mentioned in yesterday's post was an unexpected find.

As the note below indicates, Jennings was scheduled to demonstrate its "transistor organs" - Continental presumably included - at a meeting of the Constructors Society in London in June 1963. A review of the event will probably have been written up for the Society (and magazine) by Alan Douglas, one of the founding members and author of some pretty fundamental books on transistor organ design. Alan was the Society's principal reviewer at this time.

Quite when Jennings joined the Society is unknown at present - perhaps not too long before Windiate was appointed though. Tom - and Jennings - only joined the "Association of Public Address Engineers" when the company's new range of PA amplifiers and microphones was ready for sale in 1964.

As for early records of the Society's transactions (from 1962 and 1963), a search is on - thanks to current members. The "Electronic Organ Magazine" did not acquire an ISBN number until 1981.

Last, simply to note that Cyril and Tom Jennings were old friends. Organist at St Aidan's in Gravesend in the mid and later 1950s, Cyril had from 1957 been a fulsome endorser of Jennings electronic church organs.

The issue in which the picture posted in yesterday's entry was published.

31st January

A chance find in a copy of the "Electronic Organ Magazine", February 1973 - a shot of the Model G organ installed by Jennings c. 1959 (along with a full set of speakers) in the Civic Auditorium, Lower Hutt, New Zealand.

In the original paper print one can just make out "JENNINGS" above the third manual.

Civic complex, Lower Hutt, New Zealand. Picture from this page.

By the mid 1960s the organ began to require increasing amounts of maintenance. Reports indicate that under certain conditions it would barely stay in tune for more than 24 hours; and when moved from one position to another on stage internal connections would sometimes break (not to mention external connections to the speaker array). A skeletal account of the organ's history can be found on this page.

In the early 1970s its electronics were replaced in their entirety, the main case little changed however, as the picture above shows.

More to come on the magazine and the Society behind it shortly. One of the last publicity shots for the Model G - July 1960 - can be seen below on this page, entry for 30th December.

30th January (2)

A detail of a Vox ("Cliff Richard") Reverb unit recently sold, pots with the date code "EJ" = May 1962, and Mullard mustards with "B2N" = second quarter of 1962, not one of the first to have been made ready for sale as its serial number appears to have been 1139 (the sequence beginning at 1000), but still fairly early, and in nice cosmetic condition.

Its original reverb pan unfortunately did not last the course, a replacement from a later solid state amp is currently in place (single main spring, red Sonotone cartridges).

30th January

A page has now been started on JMI serial number plates for Continental and Super Continental organs, a sort of companion to the one set up for the Univox a little while ago. As the plate most commonly used for Continentals, late 1964 to late 1967, was also affixed to Italian-made organs earmarked for sale in Europe, one naturally has to look to other characteristics to work out actual place of manufacture, late 1966 to April 1968 (the end of JMI).

Whether Vox Jaguars ever had Jennings plates is not known for certain at the moment. Most that come to light either have standard Italian (Thomas Organ) plates or none at all. One that surfaced some years ago was accompanied by the intriguing note that "...the organ is dated 1968 inside the lid and was manufactured by Jennings Musical Industries Ltd of Dartford, Kent, UK and was originally supplied by The Sound Centre, Cardiff." Unfortunately pictures of the date and statement of manufacture, such as it may have been, were not posted. Perhaps an Italian plate and inspection sticker?

At any rate, few Jaguars come up for sale in the UK.

29th January

Thanks also to Martin, a shot of the plate on the toobox that Rodney Angell made for himself at JMI. From 1965, Rodney worked primarily as an engineer, dividing his time between the R&D and Organ Departments. The plate, as can be seen, is of the type used on organs for a short time in late 1967 and early 1968 - "Vox Works, Erith. Kent" stated instead of "Dartford, Kent, England". A small number of late (very late) JMI Continentals and Super Continentals have plates of this sort.

Note that the voltages cited are 200/250V. The days of making organs for the American market were well and truly over.

26th January

Thanks to Martin, a detail from the only known set of circuit diagrams for the Univox J5. Drawn up neatly in 1954, the sheet in view is likely to embody the changes made by Derek Underdown in the weeks following his arrival at Jennings in June 1952.

The extent to which the very first, pre-Derek, J5s (those made from February to June 1952) differed from the diagrams has still to be established. The main Univox index page can be found here.

Date of redaction: September 1954; date of the original drawing: July 1952.

24th January

Sad to say, the speaker cabinet of AC30 Super Twin serial number 5112N - pictured in entries below (13th and 16th Jan.) - has been parted out by a trader on ebay UK, cabinet and speakers listed separately. Sigh.

23rd January

A later Jennings badge (later 1950s) on a German-made Electra Accordion, a make that Tom does not appear to have advertised widely.

Instances of accordions with these badges will be collected together on a page of their own in due course.

22nd January (2)

Inadvertent similarity? Although there is no explicit mention of the Continental Grand in the Jennings adverts and lists that have come to light, Tom was for a number of years sole distributor of Excelsior in the UK.

Flyer from the late 1950s (an original copy appears in a set said to be from 1958). Lincoln Continental emblems at the time were more rectilinear. But then there's always the possibility of "Hotel Continental" signs and so on ....

A quick detail from an advert published in the popular music press in December 1962. Obviously not the same font, but the general idea ...

The design of JMI adverts in later 1962? Probably a combination of Tom, John Williment (General Sales Manager), and the JMI draughtsmen.

Williment newly appointed in June 1962.

The fancy form of "VOX" in view goes back to Spring 1961 however.

Detail from an advert placed in the music trade press in June 1961.

22nd January

Thanks to Martin, a great detail of Jack Jennings, Tom's brother, in action in "Jennings Electronic Industries" days, c. 1971. When Tom was dismissed from JMI in the autumn of 1967, Jack left too, becoming, once Tom had set things up, head of despatch at the new company much as he had been at JMI. His job was principally to oversee packing and sending, and to stamp and record serial numbers, dates, destinations, and so on. If only something as small-scale as the clipboard that we see had survived.

The destination of the lorry, parked at Dartford Road, was Wupperthal.

21st January

An Excelsior "OO", sold by Tom in April 1950, at the other end of the spectrum from the Boselli (in yesterday's entry) in terms of quality and price. Excelsiors command huge sums today.

The sales receipt for the accordion pictured above, which appears not to have had a Jennings badge (or at least no longer has one). "Manufacturers" covered a range of things specially made or "re-branded" for Jennings. A few were indeed produced in the shed behind number 119 however.

March 1950, Tom's magazine. Tom held the trademark for Ranco in the UK (granted in August 1951).

20th January

A Boselli "Maestro" accordion in blue pearl finish with a Jennings badge on its rear panel, possibly listed in an advert placed in the music press in October 1956. Bosellis seem to have been stocked by Jennings only occasionally.

Accordions with Jennings badges are fairly scarce these days. Whether all that passed through the shop were given one is not known at present.

Business at "The Accordion Centre" in the basement of 100 Charing Cross Road was good through to 1960. Sales thereafter were almost completely eclipsed by amplifiers. In December 1960, "Musicland", the Jennings shop in Bexleyheath, held a massive clearance sale of unsold accordions (only one Boselli, in black, listed).

Blue pearl finish, gold glitter trimmings.

October 1956. Larry Macari was overseer-in-chief at the Centre (in the shop basement). It is to be hoped that an example of the "FREE complete lists" mentioned will eventually surface.

19th January

Recently come to light in Europe - an AC10 Twin with a fancy control panel of the sort also found on AC10 serial numbers 3805 and 4030. The seller gave the number of the amp in view as 3372, which is impossibly low for a Twin. 3872 seems much more likely. Speakers are blue Elacs (10N/81).

See Glen Lambert's page on Vox AC10 control panel types.

18th January

Currently on Ebay in the UK (no affiliation) a late JMI AC30 modified by Dick Denney for its present owner. The footswitch (effects and channel switching) communicates with a unit added to the rear of the amp and was evidently made by Dick primarily from JEI ("Jennings Electronic Industries") parts - rotating foot pads, for instance, as on a number of JEI pedals (1968 to c. 1973).

17th January

Thanks to Andy, a couple of shots of an AC10 saved from oblivion (discovered in a skip) - late 1964, probably a serial number in the high 4500s, silver Elac speaker still in place.

The "TEN" logo still present bottom right on the grille.

The latest of the Mullard mustards have the date code "B4N" = second quarter of 1964 for their manufacture.

16th January

A few more pics of the chassis of AC30 Super Twin serial number 5112 - assembled by Westrex, Haddon transformers, phantom cut-out by the rectifier; rectangular trimmer in the preamp, and blue Hunts 25uf bypass caps (originally).

Numbers of electrolytics have the date code "HSW" = 25th week of 1961 for their manufacture. The Mullard rectifier valve has the old-style code "B1F" = June 1961.

Chalked initials in the speaker cabinet are "FW", "DB", and "LF" - known from other Super Twins (see this page).

14th January

The Musicians' Union Directory of members for the South-East (from Oxfordshire to Dorset), 1964. The JMI advert is well enough known. Eddie Moors was one of Tom's oldest local dealers in the region. Note the anachronistic images of the Univox keyboard and AC30 in beige vinyl.

13th January

Thanks to Damian, pictures of the Celestion blues in the speaker cabinet of AC30 Super Twin serial number 5112N: - date code "26BF" = 26th February 1961, on the face of things good and early as known blue T530s go. The cone code - RIC 1FY - also figures on the speakers in what appears to be a late-ish AC30/4 cabinet - see this page. That AC30/4 as we have it is clearly a relatively modern "composite" however. The chassis (certainly) does not belong with the box.

Going solely by the alphabetical sequence of cone codes, "RIC 1FY" would seem to fit best in early 1962. Was the "F" for 1961 in the gasket code an error?

Just to note that speakers with labels at 90 degrees to the horizontal are also to be found in Super Twin serial number 5648N, pictured below.

More on serial number 5112N to come shortly.

AC30 Super Twin serial number 5112N.

AC30 Super Twin serial number 5648N.

12th January

The first style of Univox serial number plate - on a J5 keyboard (thanks to Martin for identifying) that was paired at some point, perhaps early on, with a slightly later main case (power section and so on).

Ensuing generations of plates gave the manufacturer as "The Jennings' Organ Company". An overview can be found on this page.

Univox J5 serial number 229. First type of plate.

10th January (2)

Late 1940s or very early 1950s, a loose-leaf Goodmans dealer catalogue, the pages in view being for its 10 inch speaker. Typically many Goodmans speakers had no trade or range name. Designation was by frame type / cone type / impedance. Most users will have gone for the 3 or 15 ohm versions.

By the mid to late 1950s, frame and magnet drum had been redesigned (though the format was still known as the "T6"). Later cones were numbered 1028 and 1030. It may be that the 1010 was still available too however.

An overview page on the various types of Goodmans used by Jennings in portable amplifiers to follow soon. An overview of their use in the console organs can be found here. Derek Underdown's drawing for the massive array accompanying the Model G is on this page.

Many early Goodmans speakers made provision for the mounting of a transformer on the frame.

The required positions of mounting holes / screws on the speaker cabinet baffle.

10th January

Thanks to Erik, some shots of AC30 Super Reverb Twin serial number 3793, sent out in an old-style square-cornered box as a number of Super Twins with numbers in the higher 3000s were.

9th January

Recently come to light, an early Jennings Univox J5 from mid 1952, twin 10 inch speakers (Goodmans), and a power section entirely different in arrangement from later units. This was the type of Univox that Derek Underdown was employed, in the first instance, to sort out. Derek began at JMI on the 3rd of June 1952. The page on Univoxes in 1952 can be found on the main Univox index page. More to follow soon.

8th January

Just to add in relation to the amp pictured in yesterday's entry that its Mullard ECC83s have date codes for November 1959, December 1960, and June 1962, the ones from 1959 and 1960 perhaps being the originals. The ECC83 from June 1962 is liable to be a later replacement. So far as one can tell, the batches of chassis with phantom cut-outs had all been used up (i.e. sent out in amps) by April of that year. The EL84s were replaced in 1966.

7th January

Thanks to Rae, some pics of an AC30 Twin probably originally with a serial number in the high 4000s / low 5000s, ready for sale in early 1962. The chassis, assembled by Westrex, has Haddon transformers and a "phantom" cut-out by the rectifier valve. Some of the original black WIMA Tropydurs survive in the preamp. The tone pot has the date code "HI" = August 1961 for its manufacture.

In company with serial number 4981, one feed of 6.3v wiring in the preamp is pink and yellow, rather than blue and yellow.

At some point in the early 1970s the cabinet was cut in half - to form a sort of Super Twin - and re-covered. The grille cloth is Watkins (WEM).

6th January

Much as in 1963, Woden had a "summer recess" where JMI was concerned - no transformers supplied from March to July (inclusive) 1964, date codes "CV" to "GV". This was a time of intensive production of AC30s. Burndept, which had relied more or less exclusively on Woden from August 1962, turned in the late spring and summer of '64 first to Albion (used by Westrex from later 1961), then to Parmeko, the gap in Woden's supply corresponding in broad brush to AC30s with serial numbers in the range mid 12000s to mid 15000s. The new batch of Wodens had August and September codes ("HV" and "JV").

The same hiatus in supply can be seen in AC80/100s (as assembled by Westrex through to early 1965): first batches of transformers from Woden in late 1963, November and December codes, "LU" and "MU", then a break until August 1964. AC80/100s sold comparatively slowly at first; the initial batches clearly sufficed.

The reason for these gaps? - the bulk of Woden's work was for industrial clients (vast transformers for power supply and regulation), the summer reserved for that.

4th January

Picking up from yesterday's entry, just to say that in mid 1963 Westrex did most most of the heavy lifting for JMI in terms of chassis production. Very few Burndept-made units went into AC30s with serial numbers in the range c. 7200 to 8400, output (and availability) accelerating again with the new supply of Woden transformers in the early autumn of '63.

3rd January

One of those seemingly anomalous chassis - produced by Burndept, Woden choke and tone pot with date codes for January 1963, but Woden output transformer with "JU" = September '63.

To judge from the undisturbed appearance of its screws, the output transformer looks to be the original. The amp to which the chassis belonged will therefore have had a serial number in the 8000s.

It may be that assembly of this chassis was interrupted by the gap in the supply of transformers from Woden. No AC30 has come to light so far with Wodens from March to July '63 ("CU" to "GU" inclusive). Only one is currently known with "BU".

2nd January

Thanks to Keith, pictures of AC1/15 serial number 3769, recently sold. Superb condition externally, the electronics (transformers aside) for the most part appear to have been renewed at various points over the past decades. The original speaker may have been a Celestion CT3757. The page on AC1/15s can be found here.

On the control panel, the legend for the Vibrato Speed has a "3" with a flat-headed top, much as on panels for AC/30s (identical layout). Most AC1/15 panels have a "3" with a rounded top. Panels earmarked for AC/30s were doubtless used occasionally for AC1/15s when the need arose.

30th December

A Jennings Organ Company pricelist from March 1960, and one of the last full-page adverts for the range (July '60) in the music trade press - just a couple more after this one.

March 1960.

July 1960.

26th December

An AC30 Twin with a serial number somewhere in the range 11100 to 11600, Treble voicing, black plastic serial number plate, basketweave vinyl (not the commonest covering at this point), Woden tranformers with "AV" = January 1964, and choke "BV" = February 1964. Perhaps of greatest note: the amp preserves its original yellow-print Mullard EL84s with paint code "LA" = January 1964, i.e. earlier than the choke.

24th December (2)

A little more on the chassis illustrated in the previous entry. What explains its form is JMI's drive during the course of late 1964 and 1965 to produce further models for the American market, ratified by the Underwriters Laboratory (UL).

Below, a detail from a large flyer produced for the Trade Show at the Russell Hotel in August '65. On the face of things, the set illustrated looks like an AC50, but the chassis is clearly suspended from the top of the amplifier section cabinet, and there is a sloping section at back for the controls.

The format of the chassis will in other words have been the same as Alan's: three blank sides, all controls and sockets on a single sloping fascia, rearward rather than forward facing.

Detail from one of the two versions of the flyer produced for the Trade Show of August '65. Both had the same illustrations but slightly different texts and graphics. Note the mention of a slider switch for Top Boost (bright switch), and ground ("Polarity") switch.

Straps on top of the cabinet (much as Fenders) for the chassis securing bolts, sloping fascia at rear with the controls, the rear of the chassis inaccessible inside the cabinet.

It is not known whether the chassis below was intended for a 10W Twin or Super Twin ("piggy-back") in the new range envisaged by JMI.

24th December

Some shots of a chassis owned by the late Alan Vale, thought - perhaps not wrongly - to have been made (in whole or part) by Dick Denney.

On the back panel in felt tip: "DICK DENNY (sic) PROTOTYPE JMI VOX / £500+ ALL ORIGINAL LESS VALVES". It may be that the person who wrote the note did not know Denney in person. From what one can see, the chassis should really be termed experimental rather than a "prototype" however.

Format: designed to hang from the top of a cab (along the lines of Fender chassis). All controls are forward facing, sockets and fittings too, including an extension speaker socket. Perhaps at this point in the experimentation the cabinet was envisaged as being substantially deeper than the chassis as we have it.

The circuitry: stands in close relation to the Thomas Organ Vox Pacemaker (V-2) on the one hand, and to JMI's UL710 (without reverb) on the other. The output transformer is a Parmeko, possibly also the mains. There is no choke. The valves will have been: EZ80 rectifier [an EZ81 more likely], two EL84s, and two ECC83s.

Controls (left to right) are: Volume; Treble; Bass; and Tremolo Speed and Depth. At left, a bright switch, and below the controls: two inputs; a footswitch socket; an extension loudspeaker socket; and three switches - Standby, Polarity, Mains.

A fuller account of the circuit to follow.

Dome voltage selector.

Unusually orange wire was used for the heater runs (and elsewhere in the circuit). Heater wiring was normally brown and black in JMI amps.

23rd December

Details of the Top Boost module added to AC30 Twin serial number 16960 - genuine JMI electronics from later 1965 and part of what appears to be a kit from the 1980s or 1990s. Such kits were common enough in these decades, often advertised in the small ads of music magazines.

Quite where the Top Boost circuitry now in the amp came from is impossible to say - either the add-on module from another AC30, or perhaps from one of JMI's boxed kits, though why not simply install it with the supplied bracket?

The sheathed flying leads connecting the module to the preamp can be seen at right in the upper half of the pic.

The large blue Hunts capacitor has the date code "IYS" = 30th week of 1965 for its manufacture.

22nd December

For those interested in the construction of transformers, the WayBack Machine preserves an interesting account by Steve Giles of the making of an output transformer for an AC30/4 - the three pages (originally posted in 2011) can be found here.

Although the pictures accompanying the text do not appear to have been saved, the account given by Steve of the make-up of Haddon OTs (from 1960/1961) is useful in its own right.

20th December

Entries for three more AC30 Twins with serial numbers in the 16000s - all Treble voicing - have now been added: - 16431T, 16947T, and 16960T.

19th December

Entries for three more AC30 Twins with serial numbers in the 15000s have now been added - 15048T, 15508B, and 15665T.

18th December

Four new/updated entries for AC30 Twins with serial numbers in the 19000s - 19225TB, 19266TB, 19321T, and 19825TB.

17th December

There are entries now for AC10 Twin serial numbers 2056, 2118, 2268, and 2678 on this page.

16th December

Entries for AC10 Twin serial numbers 1646, 1940 and 1964 have now been added on this page. Further 10s to come shortly.

14th December

Perhaps the chassis pictured below was created/pimped up as a sort of practical joke (the creator is known):

CHASSIS: - produced by Westrex late 1961 / early 1962. Re-welded "phantom" cut-out beside the rectifier valve. Now crudely media blasted.

TRANSFORMERS: - original Haddon mains and choke. The output transformer is a replacement from a much later AC30. Unfortunately the mains transformer has been given a Parmeko label taken from some other amp. Perhaps the media blasting blasted off the original Haddon label.

COMPONENTS: - blue Hunts electrolytic caps with "WDW" and "HTW" = 18th and 24th week of 1961 for their manufacture. The tone pot has "FI" = June 1961.

WEIRDNESS: - recently introduced Mullard mustard caps (with a variety of later date codes) have lurid red dye/paint/nail varnish on their solder joints - not the slightest attempt to match the original Westrex joints. Why bother at all?

CABINET: - a Super Twin amplifier section box, hard to say for sure, possibly a repro.

9th December

Thanks to Johann, pictures of Italian-made AC30 Twin serial number 2773 (TB), signed off in March 1970 though likely to have been ready earlier, have been added here.

AC30 Twin serial number 2773.

7th December

Cathode bias resistors in AC30s: in 1961 and 1962 the value conventionally used was either 80 ohms or 82 ohms, generally a green-bodied Welwyn ceramic rated at 4.5 watts.

82 ohm cathode bias resistor in an AC30 chassis assembled by Burndept, early to mid 1963 (Woden transformers dated "AU" = Jan. '63).

In the summer of 1963, as has long been known, the value of the resistor was reduced to 50 ohms (an addition dated 14th June on the main service sheet) in order to gain more power from the EL84s, a change that resulted also in hotter running.

As to the point at which the new value was introduced by the contractors charged with assembling AC30 chassis (Westrex and Burndept), evidence is scanty at the moment, the earliest instance in terms of available photos being AC30 serial number 8298. One should probably be looking more to amps with numbers in the higher 7000s for the actual point of changeover however.

50R cathode bias resistor in AC30 serial number 8298, small detail.

So far as one can tell, Westrex normally used a 50 ohm Radiospares cement resistor, Burndept a green ceramic Welwyn 47 ohm, the closest value available. Welwyn did not produce 50 ohm ceramics.

5th December

The Beatles, Paris Theatre (London), 18th December 1963, a good glimpse of the backs of the three AC30s, Top Boost controls centre (as ever) and serial number plates to their left. George Harrison's had a sticker on its plate.

A few days later the band received new amps from JMI: AC50s for John and George, and an AC80/100 for Paul.

3rd December (2)

The first entry for today has been readjusted. Also to note the presence in serial number 21944, normal for the point of production in view, of the later (latest) form of JMI control panel, introduced during the course of the 21000s, the earliest instance so far being serial number 21937.

Detail of the control panel of serial number 21944, the letters of "JMI" on individual panels of silver lying in between (ie. not running into) the main horizontal bounding lines.

3rd December

Recently sold in Europe, AC30 Twin serial number 21944 TB, its guarantee envelope still extant. The amp is likely to have been ready for sale in early 1967 - no shots of the electronics unfortunately.

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