Vox AC30 website

Vox AC30 website updates

2026

8th September

A couple of details of a late Domino Bass chassis assembled for JMI at some point in 1965 (probably mid) by Triumph Electronics in Purley: output transformer stamped "5200 15" (15 ohms), mains transformer made by Allen.

Allen transformers were also used later by Burndept for the JMI solid state "Traveller" amplifier.

Output transformers marked "5200" (made by Richard Allan) are standard in AC4s, which the Domino Bass effectively was in terms of electronics.

Just to say that the cabinet of this Domino Bass now bears the serial number plate of a Domino Reverb along with a note on yellow dymo tape to the effect that the amp had been consigned to Denis Peyton of the Dave Clark Five by JMI. Honestly, as if. The man (initials JH) who added the tape and probably the plate too evidently had some sort of abiding obsession with Peyton. Why is anyone's guess. If you see a guitar or amp purporting to have some connection with Peyton you can be sure that JH has been at work.

The Domino Bass chassis pictured below is perfectly ok though (ie no fiddle-dee-dee).

7th September

Pictured rehearsing in mid or later 1964, "The Black Sheep" with a Bird "Golden Eagle" amplifier (not a 30 Reverb as stated yesterday). Its cabinet was evidently divided into two main sections, a compartment for the reverb spring at foot and a larger compartment for the amplifier chassis and speaker. A further smaller compartment was provided for the mains cable.

One of the band's Super Twin amplifier sections front down, and the Bird "Golden Eagle".

"Vintage Guitar Magazine" has some useful photos of a surviving "Golden Eagle".

6th September

Below, details of a first generation chrome AC30 stand from a set of negatives of the band "The Black Sheep" rehearsing in a church hall mid to late 1964. The band (two guitarists, a bassist, drummer and keyboard player) are pictured with: two beige AC30 Super Twins; an early chrome stand; an AC30 Twin in black; a reed organ; Vox Continental with sloping top; a Fenton Weill Auditorum 30; a Selmer Bassmaster and Goliath cabinet; a Bird 30 Reverb amplifier; Vortexion PA amplifier to drive a pair of Vox LS40 speakers; Reslo stands and mics; and a fairly rudimentary drum kit. Whether all these things were theirs is unknown.

Details of the early AC30 stand belonging to "The Black Sheep", mid to later 1964.

5th September

Three types of JMI hang tag. These were normally tied to guitars, accessories, and amplifiers before packing. The two in the first picture are most common: "VOX" in cursive into 1964; "VOX" in block capitals from late 1964 through to 1968.

The example on its own in the second picture is scarcer, encountered so far only on one JMI amp from 1966, and may have been devised principally for exports to the USA. The form of "VOX" is the same as that on the tag devised by Thomas (third picture, below).

Thanks to Heinz for the picture.

4th September

The speakers of AC30X serial number 574, on the left a Celestion T900 from January/February 1964, on the right a T1074 from mid '64. The two are wired in series. As the T900 is normally 4 ohms and the T1074 15 ohms, a total series impedance of 19/20 ohms is in view. The speakers were connected into the 8 ohm tap on the terminal block. Was the T1074 mis-stamped, being in actual fact a 4 ohm T900? If not, power will not only have been unevenly distributed between the two, but the output of the amplifier seriously curtailed by the load on the output transformer.

3rd September

Seen doing the rounds a little while ago, AC30 serial number 7188, its cabinet with sloping edges similar to those on the T60 cabinet mocked up by Mick Bennett, JMI's principal wood craftsman, in 1963.

It certainly seems possible that the AC30 cab was Mick's work, perhaps a trial piece that found its way - for whatever reason - into the production run. The sloping edges, decorative as they are, can hardly have been thought viable either in terms of cost of manufacture or longevity of use though.

31st August

Some shots of AC30X serial number 574, thanks to Steve, its documentation showing that the amp was in the hands of the "Amsterdams Accordeonpaleis" by 9th January 1965 and purchased by the original purchaser on the 31st.

Evidently someone in the "Accordeonpaleis" thought that it was actually a species of AC50 though, a forgiveable error as the cabinet of the AC30X, an uncommon model, was of the same size as a standard AC50 SDL speaker cab. "AC50EX" was therefore noted on the shop's guarantee card and a rather half-hearted attempt made to change "AC30" on the serial number plate and on the JMI card into "AC50".

The speakers are blue Celestion 15s (type to be confirmed), unusual for an amp produced late in the run. More to come in due course. The page on the model can be found here.

The JMI card is stamped "11074" top right, but the serial number corresponding with the plate is given at foot. So far no AC30 Twin serial number 11074 has come to light.

30th August

Thanks to Steve, some details of AC30X serial number 574, exported to Holland in early January 1965 and purchased there later in that month, coming shortly.

29th August

Recently come to light, two more early Continentals, one with the lowest serial number currently known, Spring/Summer 1963, the other from later in the year. This brings the total number of certain instances (there are uncertain ones too) of surviving Continentals with square lids and roller switches, their legends on trafolyte, to 15.

Thanks to Tony for the picture.

An illustrated overview of surviving early Continentals to follow - a sort of parallel to the page on the various changes introduced during the course of production in 1963 and early 1964.

28th August

Details relating to the various versions of the Vox Riviera organ will now be gathered together on this new page. Below, a shot of Dave Roberts of JMI demonstrating at the Frankfurt Musikmesse, March 1968. It is interesting to see that the music stand bears the legend "Continental" in small rather than "Riviera". A surplus of stands presumably remained following the decision, in late summer 1963, to supply Continentals without them. JMI promotional images published in 1967 show a Riviera with a stand bearing the correct legend.

March 1968, JMI's last major trade show.

27th August

November 1969, advert for the Super Continental 2 and the Riviera I and II placed by Macari's in the mainstream music press. The Riviera II, a more extensively equipped version of the Riviera I, was introduced in late 1968. An overview of the circuit diagrams currently known to survive for the Rivieras is given in the entry below, 18th July.

24th August

A short section on speakers has been created on the page for AC30 Expanded Frequency amplifiers. The rule of thumb is that Celestion T900s (4 ohm) were the norm in late 1963 and for the first half of 1964; T1074s (15 ohms) were fitted sporadically though.

In late 1964, the pattern is similar if a little fragmented: one finds Celestion T1116s (4 ohms) in some amps, T1109s (15 ohms) in others. To what extent this was a consequence of supply is not clear at the moment. T60 and 2 x 15" speaker cabinets conversely sometimes have T1116s instead of T1109s.

19th August

A further AC30 Expanded Frequency fairly recently come to light in superb condition,serial number 10783. More to follow.

18th August

A short overview of 15" Pulsonic cone codes, concentrating for the moment on the cones fitted by Celestion to early spider-framed T900s (4 ohms) and T1074s (15 ohms) in Jennings blue. Model type - T900 / T1074 - had no bearing on the manner or order in which cones were fitted:

40 751/002 (T900): - AC30X serial number 9906. - "40" corresponds to October / November 1963 where Celestion T530s are concerned.

53 751/002 (T1074): - stray speaker.

53 751/002 (T1074): - one of the two original speakers in the cabinet accompanying AC80/100 serial number 177.

56 751/002 (T900): AC30X serial number 9906.

2 751/002 (T1074): - stray speaker.

8 751/002 (T900): - stray speaker.

10 751/002 (T900): - AC30X serial number unknown.

The main question arising is how far above "56" the initial sequence of numbers went. The first runs of Pulsonics for Celestion blues went to "71" before resetting at "1" - see this page.

17th August

The heading of the page on AC30s with serial numbers in the 6000s has been adjusted to take account of the fact that some of the very earliest were evidently ready for sale in late 1962, a case in point being 6033N, original sales receipt dated 24th November, '62. The majority however are early 1963 through to mid (component and speaker date codes being decisive). It is well worth reiterating that speakers consistently have the latest date codes of any component that went into an AC30.

14th August

Great Yarmouth, summer season 1963, Vox equipment and Continental organ for Helen Shapiro's shows.

13th August

Super Twin serial numbers 5854 and 9979, feet similar to the ones in the shot of Freddie and the Dreamers below. The former's are evidently closest in size and appearance.

AC30 Super Twin serial number 5854.

AC30 Super Twin serial number 9979.

12th August

A detail from one of Dezo Hoffman's shots of Freddie and the Dreamers with their Super Twins - no corner protectors, covered in deep blue vinyl? - later 1963 / early 1964 for the photo.

All three amplifier sections have large white rubber feet. Doorstops?

8th August

Sone notes, thanks to David, on AC30 Expanded Frequency serial number 9906X. In company with most Westrex-made chassis of this type - copper panel, integrated Top Boost controls - that have surfaced with readable date codes, dated components range from March to August 1963 ("UC" to "UG").

On the underchassis, an "X" in red crayon, and the Westrex checker's initials "DP" are present, again, in common with other Expanded Frequency chassis.

The speakers are spider-framed Celestion T900s in Jennings blue, 4 ohms apiece, one early with extrusions (lugs) on its frame, the other without. Although the wiring run is original, the solder on the speaker terminals was renewed or redone at some point. Celestion began producing T900s for JMI after September '63.

In terms of the Pulsonic cone codes: the earlier of the two speakers has "40/751/002". Where T530s are concerned, "40" corresponds to production in October/November 1963, i.e. not too far removed from the point at which serial number 9906X will have been ready for sale.

The second speaker has "56/751/002", which has no parallel among T530s from later 1963 or 1964. "56" is presumably 16 weeks after "40" though, so production likely in January/February 1964.

AC30X serial number 9906.

5th August

The beginning of the end, early September 1967, Royston dismisses Tom's public relations consultants. Just under 30 days later Tom was gone.

According to market reports published in the music trade press, Royston, which had taken a controlling interest in JMI in January 1963, had been on very thin ice since late 1966. 1967 was the straw that broke the camel's back.

Local Kent press, early September 1967.

30th July

A text emtry has been created for AC30 serial number 6366N, early 1963. Pictures to follow soon.

Pictures also to come of an interesting AC30/4 that passed through Alan Pyne's shop twice in the 1970s.

28th July

Thanks to Anton, pictures of an AC30/4 chassis now in a newer cabinet, and one of its two surviving Celestion blues, date code "06FF" - 6th June 1961. The Ric cone code is "RIC 1 XK" - now registered on this page.

27th July

Thanks to Lars, new pictures of AC10 Super Reverb Twin serial number 3286, late 1964 / early 1965, trapezoid amplifier section, have been added here.

AC10 Super Reverb Twin serial number 3286.

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.