23rd July

Yesterday's entry now has a better image of the Peter and Gordon Vox promo shot.

22nd July

A quick shot [updated, 23rd July] of a Vox promotional photo of Peter and Gordon, taken in Dezo Hoffman's studio, probably later 1964.

Empty cabinets, LS40 column speakers without logos.

18th July

Below, a couple of details from a full-size layout sheet for the control (escutcheon) panel of the Riviera 400 organ - TRA/054. The Riviera 400 was officially unveiled in the UK at the Russell Hotel Trade Fair, August 1970. The note, presumably both for supplier and production team, that "2-SAMPLE ESCUTCHEONS TO BE SUPPLIED BEFORE COMMENCING PRODUCTION" is sensible enough, though one can't help wonder whether something hadn't gone awry in a past project.

Below, a list of the sheets that are known to survive for various models of the Riviera - some details on the Riviera 1 on this page. Further notes on and photos of these sheets to follow.

TRA/012 - Riviera 1 & 2 reverb layout.

TRA/022 - Riviera 2 sustain layout.

TRA/023 - Riviera 1 & 2 pre-amp layout.

TRA/024 - Riviera 1 & 2 percussion layout.

TRA/025 - Riviera sustain tremolo layout.

TRA/036 - Riviera 1 & 2 reverb assembly.

TRA/037 - Riviera 2 block diagram.

TRA/038 - Riviera 2 walking bass layout.

TRA/042/1 - Riviera 2 upper console wiring.

TRA/042/2 - Riviera 2 lower console wiring.

TRA/041/1 - Wiring diagram upper console.

TRA/041/2 - Wiring diagram lower console.

TRA/043 - Riviera 1 Block diagram.

TRA/054 - Riviera 400 control panel.

TRC/03 - Riviera 1 & 2 reverb circuit.

TRC/04 - Riviera 1 & 2 percussion circuit.

TRC/05 - Riviera 2 sustain circuit.

TRC/06 - Riviera sustain tremolo circuit.

TRC/07 - Riviera 2 walking bass circuit.

TRC/08 - Riviera l & 2 P.S.U. Circuit.

VTA/100 - 100 watt transistor organ amp.

17th July

A detail from OS/037 (dated November 1963) for the Domino Reverb combo. The input portions of the circuit are unusual but clear enough in their operation. The physical form of the reverb tray - indicated simply as "DELAY" - is completely inscrutable though, perhaps deliberately unspecific. Presumably if it failed one wrote off to JMI for a replacement or sent the amp back.

16th July

Two further pics of the Domino Reverb chassis illustrated yesterday. Visible date codes are confined to the Mullard mustards - "A3N", "B3N", "B/63" = first and second quarters of 1963. A similar spread occurs in Domino Reverb (combo) serial number 1635.

15th July

Thanks to Dave, some shots coming of a Domino Reverb combo chassis. Long without its reverb tray and cabinet, the chassis came to light in LA in the 1990s when a local music shop closed down.

The page on the model can be found here. The main index page for the Domino range is here.

13th July

June 1963, an advert for the Tornados on tour with the Joe Brown "Big Beat" show. A closer detail of the Continental to come. Also a report (from later 1963) of the "Vox organ" owned by "The Federals", a northern Scottish band.

11th July

Thanks to John, some pictures of AC10 serial number 3270 - a two-input "Amplifier No. 2" - coming shortly.

10th July (updated)

The first main type of cabinet swivel mount and handwheel, VOX in large cursive, used principally for early AC50 trolleys, and side stands for AC30s and Line Source 40 columns. Other instances are also known.

In terms of assembly, the third picture, below, indicates the main lines: (i) a compression washer (normally translucent plastic) was fitted first over the main cylinder of the cabinet mount; (ii) the circular ring of the side stand or trolley followed it; and (iii) a metal disk was placed on top, the handwheel then screwed down to fasten the cabinet at the desired angle.

Often the cabinet mount would have a phenolic ring around its central cylinder (i.e. between the cylinder and the inner face of the ring on the trolley or stand).

LS40 stand. One can just make out the plastic disk underneath the ring of the side stand, and the phenolic ring between the cylinder of the cabinet mount and the inner face of the stand.

9th July

A detail of one of four Elac 10N/86 speakers from a Vox Line Source 40 column, fibreboard gasket made by "Thames Board Limited", which was based in Purfleet, Essex. "Thames Board" was acquired by Unilever in 1964, though continued to trade under its own name.

All four gaskets were stamped by Elac "03656". Could this mean March '65 for their manufacture? Sets from other LS40 columns have "01656".

Where and how Celetion sourced its gaskets is not known for certain at present, though "Thames Board Limited" is a definite possibility.

8th July

Some quick shots of a two-section domical footswitch (used up to mid 1962). The removable top of the casting has a 7/16" thread to screw onto the neck of the Arrow switch. The small metal ring tightens down on the outside of the top.

The main page on footswitches can be found here.

7th July

The documentation supplied with a Dallas-made "Vox Sound Limited" AC30 from May 1975 - serial number 1655. Dallas-made AC50s were supplied with identical sets of paperwork. The model and serial number of the amp in view were generally not noted on the envelopes (in contrast with standard JMI practice).

The page on early Dallas AC30s can be found here.

2nd July

Further pics of "Vox Sound Limited" AC30 serial numbers 25933 (post rebuild) and 1281 have now been added to this page, along with a detail of the brimistor visible in the latter.

The brimistor - "Brimar-resistor" - was a sort of in-rush current limiter adopted by JMI for its Vox AC100s (late 1965 on) and later solid state rectified Vox AC50s. It was also used by VSL for its V100, a version of the former brought to market in Spring 1970. Pages from the Brimar booklet can be seen here. Where AC30s are concerned, the brimistor came in with solid state rectification and printed circuit boards (1972).

Brimistor.

1st July

Coming shortly, thanks to Mark, pictures of two late AC30 Reverbs made in the Birch-Stolec factory in Hastings (link to the page in the entry below, 25th June), and new pics of serial number 25933.

25th June

Currently on ebay, an early "Vox Sound Limited" AC30, serial number 25189. No affiliation. Its speakers - Celestion "silvers" (T1088) - are dated 20th August 1970, presuambly part of a batch that arrived at the Vox factory either in September or October. There a good number of examples of late September codes. This is the only instance from August so far. The earliest T1088s to have surfaced to date in these amps are dated November 1969.

The page on the "Vox Sound Limited" AC30s will be updated in due course.

20th June

The encapsulated ("dome") voltage selector introduced by JMI in mid to late 1964 was evidently made or sourced by Re-An, a few streets over from Dartford Road. A page on its jack sockets can be found here.

JMI used these new-style selectors - they superceded the older plug-in link selector - in their thousand across its range of amplifiers, both valve and solid state, and its accessories. Below, the line for the selector in the Burndept parts roster for the Vox Supreme and Super Foundation Bass power section.

The voltages printed on the control panel of the amplifiers fitted with these were normally: 115v, 160v, 205v, 225v, and 245v.

Images of the dismantled selector were originally posted on this page in 2024, entry for 6th July.

19th June

August 1967, a Burndept parts roster for the power section of JMI's Supreme and Super Foundation Bass amplifiers. 100 assemblies were envisaged and provisioned for in this batch. Reference is made periodically to JMI's mechanical drawings - for the control panel, the drilling of the heatsinks, and so on.

The notes on the final sheet indicate that such rosters were drawn up for previous batches too. AC30s, AC50s, AC100s, organs, and accessories, were presumably documented in much the same way. Burndept must at one time have had cabinets bursting with paperwork relating to JMI contracts.

That the procedure of making such rosters went back at least to 1966 is clear enough, perhaps having begun in mid 1964, when JMI moved into Burndept's West Street Works. Whether it went back further - to 1962, say - is unknown. Nor do we know anything much at present of contract record-keeping at Westrex. Perhaps something will materialise eventually.

A further class of documentation currently lacking is the Burndept and Westrex build sheets, i.e. the sheets created for the assemblers on the work benches. Stories used to pop up occasionally along the lines of: "I know a man who knows who has them" sometimes followed by mention of Eric Snowball. But alas, no. Fun all the same.

At any rate, if anything is certain it is that the circuit diagrams sent out by JMI to repairmen and hobbyists - the OS and other series - have (and had) precious little relevance to the actual assembly of chassis.

18th June

A couple of updates to the page on early AC4s. Several of the blue Daly electrolytic capacitors visible in these early amps appear to have two-letter date codes: "HH", "LH", and "PH". On later Daly caps, year normally comes first, then month, "WB" for instance meaning: 1965, February. Can the Dalys in these AC4s really be 1950s production? Perhaps, at a pinch....

17th June

An entry for AC10 Twin serial number 1952 coming shortly. Thanks to Steve for details.

16th June

Sad to say, but perhaps only to be expected, a couple more TV Front AC30 Twins - towards the end of this page - appear to have repro diamond-pattern cloth. Quite what that means for those amps will have to remain open for the moment.

The one currently on offer in the USA is unfortunately a lash-up from top to toe.

14th June

A sample of some genuine JMI rexine from 1960 (AC10 serial number 3224) compared with repro material, as one might find for instance on a lashed-up (pretend) TV Front AC30 Twin.

Beware of TV Front Twins and the monkeys that fabricate them.

Above, genuine rexine from 1960.

Repro rexine. Note its general crudeness.

Closer detail of the repro rexine.

13th June

A glimpse of JMI's design process - the steps leading up to full production, in this case, of the T60. In November 1962, Jennings placed a short note in the music trade press to indicate that prototypes for the T60 were "well under way". It is probably no accident that the earliest known circuit diagrams / layout sheets date from close to this time.

A62/031, below, included by Jim Elyea in his "Schematics Portfolio", is one of two schemas for the T60 drawn up in October 1962. JMI presumably provided Burndept, the contractor charged with assembling the amplifier's chassis, with copies soon thereafter.

So far as one can tell, the first batch or batches of fully finished factory-made chassis - the "prototypes" mentioned - are likely to have been ready in or by December. The earliest T60s known to survive have components with November '62 date codes - notably the Woden interstage transformer (date code "LT").

The sheet as we have, based on one initially made in October 1962, was drawn up in January 1963.

JMI doubtless supplied Burndept with similar "real-world" layout sheets for the AC30 and other models - to be copied (and perhaps broken down into sections) for its work benches. More to come on Burndept's procurement and assembly procedures shortly.

Just to signal though - as has long been known - chassis were occasionally assembled in non-standard ways. That is certainly so in the case of a black panel T60 from late 1963: - components as other Burndept-made T60s, but no chassis number, and an eccentrically-arranged early-format (?) tagboard.

12th June

Local Kent press, late February 1964. The successful applicant is likely to have been Albert Hogben, who worked for JMI until late 1967, then for Tom in Tom's new company, Jennings Electronic Developments, later Jennings Electronic Industries.

11th June

Two more early pictures of two-tone AC15s in use: The Cordettes, and Dae Laine and the Strollers.

10th June

April/May 1963, the earliest Jennings full-colour advert in a mainstream music magazine. The photo of The Shadows, taken by Dezo Hoffmann, was reversed either by JMI or the publisher. Hank's parting is on the wrong side.

April/May 1963.

8th June (2)

Hullabaloo again, 20th April, 1965, Alan Price, still with The Animals, using the studio's Continental with the "reverse" plaque/sticker designed (and added) by Thomas Organ. The organ was also used on the programme by The Sir Douglas Quintet in May - screengrab below.

April 1965.

8th June

To be added in due course to the page on the Continental in America, some shots of the "reverse" plaque/sticker - black lettering on a white background - designed by Thomas Organ, and perhaps best known from the film of the Beatles' concert at Shea Stadium, 15th August, 1965.

The organ was sold at Christies in 2008.

This was by no means the first time that Thomas had used such a plaque. Below, a screengrab from video of the organ provided for the Sir Douglas Quintet on "Hullabaloo", 4th May, 1965:

The Sir Douglas Quintet performing on "Hullabaloo", May 1965. It is to be hoped a better image can be obtained to compare with the picture of the organ used at Shea.

Later in 1965 (certainly October), a further Continental was fitted out with a reverse plaque, slightly wonkily positioned. The organ in view was used by the Miller-Goldberg blues band in late 1965 and probably also by Paul Revere and the Raiders on a TV show in March 1966. It has not been possible so far to find an image of any other occasion on which the Raiders used this Continental.

So far as one can tell Thomas used these plaques exceedingly sparingly - there are no photos of a Continental with one anywhere, for instance, in its promotional magazine "Vox Teen Beat", published every six months or so from Spring 1965 to 1969. Perhaps in time a Continental with an original "reverse" plaque will come to light - in the States though, not the UK.

Some care is needed as a repro has been available for a number of years.

There is also a white and black plaque with the "VOX" logo on the organ's side.

A poor screengrab of Paul Revere and the Raiders, but the white and black plaque is clear enough.

7th June

A shot of The Hi-fis taken in early 1965, Brian Bennett with his late square lid Continental from mid to later 1963 - no music stand (or fixings for one) on top of the lid. Other photos show that the back panel had no logo.

The page on bands with early Continentals can be found here.

Photo from this page.

6th June

An entry has now been made for AC4 serial number 2406, one of the last to have been issued in the old-style small case. Thanks to Colin for the pictures.

AC4 serial number 2406.

5th June

A good detail from one of Dezo Hoffman's promotional shots of the Stones. In 1963 - probably towards the middle of the year - Jennings supplied him with a new set of equipment, all with black vinyl covering, for such pictures: at least two AC30s, a Continental organ, and a T60 bass set. None of the cabinets had speakers or chassis. The T60 amplifier section was simply the box.

Dezo's first set of equipment - beige vinyl covering - presumably went back to Jennings when the new lot arrived.

Other bands photographed with the new amps and cabs were: The Beatles, The Hollies, Gerry and the Pacemakers, The Swinging Blue Jeans, The Merseybeats, the Mike Cotton Band, The Gamblers, and a good number of others.

Among those photographed with the beige-covered Vox equipment in earlier months were Peter Jay and the Jaywalkers, The Echoes, and The Escorts.

For other instances of the black and white Shepherd's castors, see this page.

4th June

To date, no surviving T60 amplifier chassis has been shown to have been built to the earliest circuit diagrams - A62/030 and A62/031, from September and October 1962, published by Jim Elyea in his "Schematics Portfolio".

Serial number 161, the earliest T60 currently known for certain, was evidently made after the revisions of early 1963 - either that or its electronics have been altered beyond recognition. That the first fifty or so T60s should have disappeared without trace is striking. Were they all inherently unstable? Did the Mulolard OC35 0pwer transistors let them down? Or - possibly a slimmer chance - did the serial number sequence actually begin at 150 (rather than 100) as it appears to have done in the case, later on, of the AC80/100?

Below, the best of two AC30 Transonic amplifier sections known to survive - TS-30 serial number 1024 (ie. the twenty-fourth or twenty-fifth made). The Woden interstage transformer is dated "LT" = November 1962, and the main Hunts capacitors have "TTH" for their manufacture = 44th week of 1962. T60 serial number 239 corresponds in these respects.

The Transonic preserves its original Mullard OC35s; the T60 has later replacements.

AC30 Transonic serial number 1024, probably early to mid 1963, electronics all original. Thanks to Steve for the pictures.

The only amplifier section with built-in tremolo caught in a photo not taken in a photographic studio can be seen below, entry for 27th May.

3rd June (2)

A couple of pieces of documentation. The first, thanks to Andrew, an overview of the specifications of the Texas Instruments 1S021 diode published by Radiospares in 1965. It is probably from Radiospares that Jennings obtained its supplies, late 1962 to 1968.

Radiospares catalogue, 1965.

The second, a sheet for the T60's circuit not much seen these days, drawn up in September 1964, presumably - as in the case of other models and their sheets - to accompany exports to Thomas Organ in the USA. A good number of T60s crossed to America in late 1964 and 1965. AC30 Transonics and Lightweights were not included in the various "deals" with Thomas.

The sheet ends with Issue 7. The two sheets most commonly seen these days take the modifications through to Issue 10 or Issue 11. Copies of one or other are often found in versions of the Thomas Organ Service Manual. To date however, no Thomas copy of the September '64 diagram has come to light. There must be one somewhere though.

Still the earlier sheet number "A/027". Later ones were redesignated "OS/062".

3rd June

The preamp of the T60/AC30 Transonic has three main sections: (i) an initial gain stage of two OC44s; (ii) volume, treble and bass network, based on the circuit published by Maynard in "Radio Constructor" magazine (see below, entry for 30th May); and (iii) a further two OC44s as a "gain recovery" stage before the driver transistor.

The initial gain stage (i) generally follows that of Mullard's public address amplifier (1960-1961), though Mullard envisaged OC71s, as it did for most of its other cascaded gain stage designs. Why did Jennings prefer the OC44? Hard to say for sure, but it may be that in practice its noise floor was lower than that of the OC71.

At any rate, Jennings, in a manner of speaking, stitched the preamp of the T60/AC30 Transonic together from existing elements.

Below, shots of one of the first Mullard semiconductor data booklets - from 1957 - containing sheets for 10 types of transistor and 9 diodes. The OC44 was new in December 1956, the OC71 had reached its settled form by November.

Whether the transistorised preamp/effects module developed by JMI in 1959 for its "Entertainment" organs had OC44s is unknown.

Mullard semiconductor data book, 1957.

Advance pages for the OC44, December 1956..

2nd June

It turns out that the "1S021" rectifier diodes in the power section of the T60/AC30 Transonic, mentioned below, were manufactured by Texas Instruments. Texas had opened a facility in Bedford around 1960 - see this page - participating in various British trade shows in the early 1960s. Over the course of the T60's production (through to early 1968), Jennings used around 8000 1S021s.

So far, no earlier analogy has come to light for the use of the Mullard OC35 as an audio output transistor. Mullard recommended the OC26 and OC36. The OC35 was "general purpose", not that that can really have mattered for what was primarily a bass amplifier.

It may be that the power section of the T60 as we have it was for the most part a Jennings design (a sort of working forward from the Mullard circuit book). Whether CTH Electronics and Audix, both early to market with solid state public address amplifiers, followed Mullard to the letter is not known.

January 1961.

In later 1963, Jennings moved from the OC35 to the OC28, perhaps in the search for greater stability and consistency. Now and again, one finds OC26s. In terms of surviving T60s, the majority have - or now have - OC28s. The principal question marks hang over serial numbers 239 and 268 (black panel, later 1963), which have modern OC28s, possibly introduced by repairmen in line with later and more common versions of the circuit diagram. All this will be tabulated in due course.

An early Transonic amplifier section, however, does retain its original OC35s. Thanks to Steve for the picture.

1st June

Picking up from yesterday's entry, a short note on the power section of the T60/AC30 Transonic amplifiers. This stands half-way between two circuits for a Public Address amplifier published by Mullard in 1960 - one with a 14V supply and an output transformer for the speaker; the other with a 28V supply and a speaker directly coupled to the output transistors (as in the case of the T60).

A peculiarity of the JMI power section is the use of "1S021" rectifier diodes about which there is little documentation. Transistor equivalents books from the 1960s and 1970s give the BYX22 as a direct replacement. Mullard envisaged generation of the HT in its circuits from accumulators (batteries) rather than a mains transformer.

The power transistors in the T60 (OC35s rather than OC26s) are arranged as the Mullard 14V circuit (above) published in the "Reference Manual of Transistor Circuits" of 1960 and 1961; in its HT voltage and directly coupled speaker, the T60 follows the Mullard 28V design.

Detail of the T60 circuit of early 1963. The initial design had only two 1S021s. The manufacturer of the diodes is unknown at present.

Two of the four "1S021" rectifier diodes in a T60 from the autumn of 1963.

30th May

A little more on JMI's work on transistorisation in 1962. Below, a detail from a circuit for a transistorised guitar preamp published in "Radio Constructor" magazine, September, 1961, by D.E. Maynard, alongside a detail from JMI's circuit for the T60 bass amplifier (as used also in the AC30 Transonic and AC30 Lightweight amplifiers).

Allowing for necessary differences - the guitar preamp was battery-powered for instance - the arrangement of the tone controls is pretty much the same. Towards the end of his article, Maynard offered a number of modified circuits (for low-impedance input signals, etc.), one using a 10K volume pot following an initial gain stage, and 10uf coupling caps, things also present (later on) in JMI's T60.

It seems likely that Les Hills and the design team at JMI used circuits or parts of circuits such as these as their starting point. Quite what prompted the employment in the T60 - and the "44" and "55" organs - of Mullard OC35s as output transistors is not clear at the moment though.

Just to note that in 1966/1967 Triumph Electronics, one of JMI's principal contractors, brought to market a transistor preamp incorporated in a guitar strap - a neat idea. Perhaps based on Maynard's article?

29th May

Text entries for a couple of later Jennings Univox J6s - serial numbers 3330 and 3365 - have been added on this page. Both are still in "old-style" form and probably from 1961 - number 3330 has capacitors dated November 1960.

28th May

A little while ago, a Continental from mid 1963 currently in the UK was found to have, beneath the vinyl that had been added in the 1980s, a fixing point for a third outer lid hinge. Two is the norm, and the lid itself, which is original to the organ, indeed only has hardware for two (in the conventional positions).

Further below, details of a similar organ - "square" inner lid, brackets for music stand on top, Bulgin mains socket and jack socket together on the back panel, etc. - used by "The Shouts" in March 1964. One and the same, or simply a twin? Probably the latter. "The Saints" (Wrexham) and "The Sons of the Piltdown Men" (Manchester) also had Continentals of this type, illustrated on this page. Nothing is known at present of the outer lids of these organs.

For a good part of 1963 the Continental was still produced in relatively small numbers. One batch tended to have features - a particular arrangement of sockets, an extra lid hinge, things of that nature - that were not carried over into the next. It took a some time - over a year - for the various elements to reach a settled form. The same is true of early AC80/100s, also made ready for sale in small batches initially (in 1964), one batch differing slightly from the other, the principal variable elements being the sockets, serial number plate, and warning plaque on the back panel.

The hole directly underneath the fixing point is for the screw for the stand's cross-braces.

Hinge mount on the body of the organ, the outer lid presumably somewhere off stage.

27th May

Below, a couple of instances of early T60 bass amplifier sets, the first made for Jet Harris and illustrated in the music press in August 1962, the second seen on stage with Sounds Incorporated, who had one of the first Vox Continental organs, in late 1962.

JMI's approach initially seems to have been to provide select bands with T60s and Continentals as a sort of new transistor-based package. The Tornados also had one of each by early 1963, seen on stage in March.

Why no diamond grille cloth on the early T60s? Perhaps at the time JMI did not have rolls that were tall enough for the speaker cabinet. That the one shown by JMI at the Russell Trade Fair in late August 1962 had a standard diamond front (and a standard vertical "pie" logo) has to be borne in mind however.

Jet evidently never used his T60 publicly, either with the Shadows or afterwards (info. kindly supplied by Terry Webster), preferring, when he had the choice, AC30s.

On the left, the trade press photo; on the right a detail from an ad in the mainstream music press, Jet Harris unfortunately wrongly spelt in both. The VOX logo looks a bit half-hearted, certainly in relation to the one pictured below.

Sounds Incorporated on stage, late 1962. The rear panel of the amp has an extra control, probably for tremolo, as below. By mid 1963 the band had a new "standard" T60.

The panel of a Vox Transonic amplifier, effectively a T60 chassis in a space-age-themed cabinet. Controls: volume, treble, bass, and tremolo.

26th May (2)

Having just noted in the previous entry that the earliest known photo of a Continental in use in concert is from March 1963, what should turn up? A picture of the Red Price Combo's Continental taken on the 5th of February, 1963, at the Doncaster Gaumont. The Combo backed Helen Shapiro, the star of the tour. The Beatles were one of the supporting acts.

Red Price appears in the short list of Continental users published by JMI in March.

5th February, 1963. Picture from this page.

16th March, 1963.

26th May

One of the earliest shop adverts to have emerged so far offering the Continental: Hessy's in Liverpool, April or May 1963. Others have been gathered on this page.

In terms of the Continental in use, the earliest instances currently known are: film and recording studio - late 1962 (Tornados and Overlanders); concert on stage - March 1963 (Tornados).

25th May

The Tornados (of Telstar), April or May 1963. Heinz Burt left the group in early March; Brian Gregg came in as his replacement a little later (i.e. not immediately). The Continental is the one seen in the posed photo with Burt, detail below, entry for 21st May.

24th May

New Zealand band "The Tornados" pictured in 1961 with a Univox J6 from c. 1954, pale covering (probably tweed pattern), large illuminating logo, serial number likely to have been in the 1300s or 1400s.

Picture from this page.

23rd May

Prelim. notes on the Mullard OC35 germanium transistor, used by JMI for the T60 (and Transonic) amplifiers; the power section of the Vox Continental; and the amplifiers incorporated in the "44" and "55" organs.

The circuits in view were, in the first instance, the work of Les Hills, who had played a leading part in designing the Univox for Tom in 1951. Les reportedly rarely ventured past the front gate of his house in Belvedere, so people from JMI normally had to go to him.

Where full-time members of the Jennings R&D Department are concerned, Alan Harding had the greatest experience of working with transistors - he developed the Vox Radio Microphone system for instance - but others will naturally have contributed to the designs, not least Derek, Dick, Ken McDonnell, and Tom, who had the final say on functionality and appearance.

Working examples of all three organs, along with the T60 and Transonic, were exhibited at the Russell Hotel Trade Fair in late August 1962.

So far as one can tell, the first adverts for the Mullard OC35 appeared in early 1960. Below, the cover of the Australian edition of Mullard's "Outlook" news and technical reviews bulletin for March and April.

Initially in the UK the retail price of the device was 48 shillings - an enormous amount (November 1960). Bulk / trade prices will have been slightly less. By the summer of 1961, retail had come down to 25 shillings. Late in the year it fell further to 15 shillings, the price of a Mullard EL34.

As for data sheets, it is clear that in June 1962 Mullard circulated new, or at least fuller details in its handbooks and technical service data collections. It is to be hoped that earlier documentation can be illustrated in due course.

Mullard Outlook, Australian edition - image from this page.

Mullard data sheet, June 1962.

22nd May

Thanks to Lee, a picture of the flyer issued by Jennings - probably in early 1960 (and extremely scarce these days) - for the Vox/Meazzi Echo. The flyer formed part of a set with the illustrated JMI flyer - headed "Temporary Bulletin" - for four Framez guitars, and a typescript description of the models.

The page on the Echo can be found here.

21st May

A reasonable detail of the back panel of the Continental regularly used by the Tornados on stage in 1963. Just visible at left, their T60 bass speaker cabinet. The AC30 has smooth black vinyl.

Continental from early 1963 (seen on stage in March): square lid, music stand supports on top; jack socket next to the serial number plate; mains socket on the underside of the cabinet. Further fixing screws appear to have been added along the top of the back panel to secure the lid. Also added, a gold-coloured plastic VOX logo (AC30 Twin size).

20th May

Some provisional notes on the circuit diagram for the Jennings 44 and 55 organs mentioned yesterday. The power section is much the same as, though not identical to, that of the T60. The preamp is quite different: a single volume control at the input; no treble or bass controls; and an unusual negative feedback network for the output. Where the T60 had four Mullard OC44 transistors, the organ amplifier employed one OC71 and an OC72.

Detail of the preamp of the 44 and 55 organ amplifier. Note that the transistors are represented as oblongs - as in the earliest surviving sheet for the T60 (A62/030). T60 sheets however normally give the positions of the collector, emitter, and base, marked "c", "e", and "b". In 1963 Jennings draughtsmen adopted the standard (circular) symbol for transistors.

The preamp of the T60 as it stood in early 1963.

Below, the register of changes, top right of the sheet, running through to August 1963 (the date of the sheet as we have it). Most relate to the preamp. R12, R13, and C12 were present in the circuit of the T60 from October 1962 and perhaps from the outset.

19th May

Below, the information panel of a circuit diagram - dated December 1962 - for a version of the T60 amplifier intended for use in two JMI organs. At least one of the two models in view was made for a customer, but so far as one can tell, neither the 44 nor the 55 found their way into general production.

It could be that they were two of the three new transistorised models mentioned in mid 1962. The third was certainly the Continental.

"M.T." is Mike Turner, who produced various sheets for the Continental.

17th May

Well-known pictures taken at the Queen's Theatre, Blackpool, 4th August, 1963. Paul has his new Super Twin amplifier section, not yet with a stand; George, the Maton guitar.

So far as one can tell (from contemporary photos) the T60 amplifier section was used for the last time at Great Yarmouth on the 28th July. From the 2nd August - Grafton Rooms, Liverpool - the new Super Twin is in view, no return thereafter to the T60. The stand is first seen in mid August (Llandudno concert), though it may have been acquired a little earlier.

Did the Super Twin come from Hessy's? Barratt's in Manchester provided the Maton in early July.

George with his Maton, the Super Twin amplifier section now on the stage floor.

16th May

The Spectres, 1964, with a Continental from later 1963 (square lid, "VOX" logo, no music stand), three members-to-be of Status Quo in picture.

A Continental of much the same date and type can be seen in the entry below for 9th May.

Photo from this page, Francis Rossi second from left.

14th May

Vox amplifier instruction manuals ("Guide to Operation"). It may be possible to pin down the date spans of (2) and (3) more precisely in due course:

1: - 1960 (and probably earlier): a single typescript sheet, half foolscap.

2: - 1961-1963: for the AC30, a small four page booklet with coloured string tie. Normally tied to the amplifier handle along with the VOX tag. An example can be seen on this page.

3: - 1963 to early 1964: a larger four page booklet covering various models, deep blue background: "Operation and Care of your VOX Amplifier" (in white print). In the case of AC30 serial number 14878, this guide was issued along with (4) below.

4: - mid to later 1964: a fold-out booklet, much the same text as (5) below, but with a rudimentary cover: a feint image of an AC30 on a lighter blue background; underneath, "about VOX ..." in white on a dark grey background.

5: - later 1964 to early 1968: the familiar fold-out booklet encompassing the available range, on the cover "about your VOX amplifier". In 1966 "VOX" was set in an oval. The print dates currently known are: December 1964; November 1965; and October 1966.

(3)

(4)

(3) and (4)

(5)

13th May

The shroud of an early Woden output transformer - August 1962 - that evidently bit the dust. Green enamel on the inside too.

9th May

The Spencer Davis group on stage, probably late 1965, a late square lid Vox Continental (from later 1963) present. The logo is "VOX" alone - other examples on this page.

7th May

A detail from a shot of Martha and the Vandellas in England, date unknown, perhaps 1964, though not a tour, powder blue AC30 Super Twin in the background. A number of surviving examples can be seen here.

Original held by Getty Images, extremely unlikely to have been "colourised".

5th May

Perhaps early 1964, a detail from a photo of the "Mark Four" on stage showing a TV-Front single-speaker AC15 or AC30 in dark covering - original beige rexine painted over?

4th May

A further detail from the Vox flyer from the autumn of 1960 (detail of the "guitar man" in yesterday's entry): The Cannons with Fender guitars, and amps with latches down the side for hinged "lift off" covers, VOX logos perched incongruously on top. Did those amps really have anything to do with Vox?

The Cannons pictured with second circuit AC15s in 1960:

3rd May

Designed (and introduced) in mid 1960 [updated 4th May: not earlier as previously stated, the earlier silhouette figures are different], the Vox "guitar man" - doubtless a nod to Hohner's "aocordion man", which goes back at least to the early 1950s. In the late 50s / early 60s Hohner was still the larger of the two companies by far.

Detail from a flyer, autumn 1960. The "guitar man" was used also in catalogues, on packets of strings, etc.

Mid 1956.

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