The dome voltage selector, which first appears in AC30s with serial numbers in the high 16000s.

Continued from the page on AC30s with serial numbers in the 17000s.

Control panels are grey. Dome voltage selectors occur as standard, as they are for amps with serial number in the 17000s. Chassis were assembled by Burndept, the contract with Westrex having ended in early 1965, shortly after JMI's move (expansion) into Burndept's West Street Factory in Erith - the "West Street Works".

The four models are still: "TB" for "Top Boost", designated "TB" on the serial number plate, the circuit's controls normally integral in the control panel; "Treble" designated with a "T"; and "B" for Bass. The two last had their own schematics, in order: OS/056, OS/065 and OS/057. "Normal" voicing no longer seems to be an active designation. Some notes on the treble circuit, which was new in 1964, can be found on this page.

A good number of the amps, or rather chassis, illustrated below are "Top Boost" models. "Bass" and "Treble versions are comparatively uncommon. Serial numbers are machine stamped, the model (voicing) - "T", "B" or "TB" - still added with hand stamps, however.

At some point in the 19000s, Burndept-made chassis with numbers stamped on the left rather than right-hand side of the preamp make their appearance, the earliest known example at present (Jan. 2022) being serial number 19535. The new position aligned the AC30 with the AC50 and AC100, which had been given numbers on the left-hand side of the preamp by Burndept from start of production - late 1964/early 1965 in the case of the AC50, Spring 1965 in the case of the AC100.

A growing collection of documents relating to the AC30 in 1965 is being assembled here.

Celestion silver alnicos - the T1088 - designed for JMI in the Spring of 1964 are standard. Grille cloth is normally now black.

If anyone knows of further amps that should be incorporated on this page, do let me know.

Serial number 18000

Noted by Jim Elyea, but probably just as a marker (i.e. not a known amp).

Serial number 18052 B - currently in the UK

Chassis assembled by Westrex; Albion transformers; dome voltage selector. BASS voicing. The original maintenance advice booklet survives with the amp.

Serial number 18118 T - currently in the USA

Brown grille cloth, basketweave vinyl, silver speakers. Output transformer (a Woden) replaced.

Serial number 18128 T - currently in the UK

Old-style (1959-1960) "Thirty" flag and part hand-stamped plate. The Woden mains transformer has the date code "KV" = October 1964, the choke "JV" = September '64. In the power section, one of the caps has "VJ" = September '64. In the preamp, the blue Hunts cathode bypass caps have "IIT" = 33rd week of '64. The main filter has "VG" = July '64. One of the silver Celestion T1088s has the date code "02MJ" on its gasket = 2nd December 1964. Thanks to Lewis for the pics.

Serial number 18173 B - currently in the UK (?)

Complete with its original cover. The Woden choke has the date code "HV" = September 1964, and the transformers "KV" = October '64.

Serial number 18216 TB - currently in Australia

Chassis assembled by Burndept, number 12722. Top Boost controls in panel. The Woden mains transformer has the date code "EW" = May 1965 for its manufacture, and the output transformer "HW" = August 1965. The choke is an Albion. In the power section, a 47ohm cathode bias resistor and gold-coloured TCC 250uf cap with "WG" = July 1965. In the preamp, Mullard mustard capacitors with date code "D4N" = last quarter of 1964. One of the gold-coloured TCC cathode bypass caps has "WF" = June 1965. The original Celestion T1088s are still in place. On the back panel, in addition to the standard serial number plate, a plate from a JMI speaker cabinet covering a hole for a jack socket. The cabinet was signed off by "Nan", who is likely to have been responsible for fitting the grille cloth and so on. Thanks to Glen for the pictures.

NEW

Serial number 18299 - currently in Australia

Chassis number 12456. Thanks to Ian for the info.

Serial number 18313 TB - currently in the UK (?)

Top boost controls integrated in the panel.

Serial number 18374 TB - currently in Europe

The upper back board, to which the serial number plate is fixed, is covered in dimpled vinyl. The rest of the cabinet has basketweave. According to the plate the chassis should be a Top Boost (with integral controls_. In actual fact it is a Treble model. The backboard and plate are likely to have been removed from another amp.

Serial number 18427 TB - currently in the USA (?)

Small pictures from ebay some years ago. Note the brown grille cloth and the link voltage selector. It may be that the serial number plate was added from some other source.

Serial number 18450

Noted by Jim Elyea, but probably just as a marker (i.e. not a known amp).

Serial number 18513 TB

Albion or Parmeko transformers. Original speakers still in place (terminals still on the frames).

Serial number 18549 TB

Top boost controls integrated in the panel. The mains transformer and grille cloth replaced. Few visible changes otherwise in the preamp and power section.

Serial number 18715 - currently in the UK

Empty cabinet (no chassis or speakers) sold in the UK in late 2023.

Serial number 18747 TB - currently in the USA

Chassis number 10753.

Serial number 18764 TB - currently in the UK

Only the speaker cabinet with its serial number plate. Baffle made of chipboard, the grille cloth originally black but faded over the years to dark brown. The "VOX" logo is composed of single letters.

Serial number 18788 TB - currently in Italy

Control panel with integrated Top Boost controls. The Woden choke has the date code "HV" = September 1964, and the output transformer "KV" = October '64. In the preamp, Mullard mustard capacitors with date codes "B4N" and "C4N" = second and third quarters of 1964 respectively for their manufacture. Electrolytic capacitors, which generally have dates closer to the point of assembly, have been renewed.

Serial number 18900 - currently in the USA

Noted by Jim Elyea, but probably just as a marker (i.e. not a known amp).

Currently in the USA

Chassis number 8407. A Bass model. The cabinet has been regrilled. Woden and Albion transformers. The Woden OT has the date code "HV" = August 1964. The Mullard mustard capacitors in the preamp have B/64 and B4N = second quarter of '64. One of the blue Hunts cathode bypass caps has "HIT" = 23rd week of '64. The main TCC filter cap in the preamp has the date code "VH" = August 1964.

Serial numbers in the 19000s

Serial number 19054 T - currently in Denmark

In excellent condition. Adjusted on import (supplementary fuses, plastic ON/OFF switch) in order to bring the amp into line with local electrical regulations. Unuaually, a Westrex-made chassis - a "Treble" as indicated on the serial number plate, which is hand stamped. Original footswitch and cover still present. Thanks to Frederik for the pictures.

Serial number 19157 - currently in the USA

Chassis assembled by Burndept for JMI, chassis number 10887. The Woden transformers have date code "KV" = October 1964, the choke "HV" = August '64. In the preamp, a mixture of WIMA and Mullard mustard capacitors, visible date codes on the latter being "A4N" and "B/64" - respectively first and second quarters of '64 for their manufacture. Thanks to Eric for the pictures.

Serial number 19206 B - currently in Europe?

Chassis assembled by Burndept, number 10xxx. In the preamp a mixture of mullard and WIMA capacitors. TCC filter caps (now renewed) have date codes "VC" and VJ" = March and September 1964. The cabinet is in good external order, "BASS" flag still in place lower right. The original Celestion T1088s are present too.

Serial number 19214 TB - currently in the USA

Serial number plate now on a Super Twin amplifier section cabinet. The accompanying chassis - grey panel, integral Top Boost - perhaps belongs with the plate.

NEW

Serial number 19266 TB - currently in South Africa

Woden transformers have the date code "KV" = October 1964, the choke "HV" = August '64. Mains transformer rewound. In the preamp, WIMA and Mullard mustard caps, some of the mustards with "B4N" date codes = second quarter of 1964 for their manufacture. Speakers are now one Thames Ditton and one Rola Celestion greenback.

Serial number 19299 T - currently in the USA

Well used. A Treble model - a "T" stamped in the aluminium of the preamp beneath the input jacks. No sign of the flash of red paint. A Top Boost unit in an enclosure has been added in the speaker compartment. VOX in single letters on the cabinet, which is covered in basketweave vinyl.

Serial number 19340

Noted by Jim Elyea, but probably just as a marker (i.e. not a known amp).

Serial number 19389 T - currently in Europe

A Treble model. Grey panel; dome voltage selector. The cabinet is covered in basketweave. Silver Celestion T1088 speakers.

Serial number 19408 T - currently in the UK

A Treble model. Grey panel; dome voltage; Albion transformers, but Woden choke with the date code "DW" = April 1965. The chassis number is still on the right side of the preamp. Silver speakers. Basketweave vinyl.

Serial number 19425 - currently in Sweden

Thanks to Niklas for the record of its existence.

Serial number 19427 T - currently in Europe

Original footswitch still present.

Serial number 19428 T - currently in Europe

Serial number 19455 - currently in Germany

Sold on ebay some time ago.

Serial number 19458 T - currently in the UK

A Treble model. Grey panel; dome voltage selector; Albion transformers but Woden choke (unreadable date code). Basketweave vinyl; silver Celestion speakers. The original cover survives.

Serial number 19535 TB

Chassis assembled by Burndept. Chassis number stamped on the left hand side of the preamp (under the input jacks) - 1287?. Note that number 11286 (below, serial number 19820, is still stamped on the right-side of the preamp). Electronically in good order - a mixture of Mullard mustard and WIMAs. A number of Mullards have "B4N" and "D4N date codes = second and last quarter of 1964. The date codes of others are unknown. The cabinet is in good order. Two new vents have been let into the top fairly unobtrusively. The original Celestion T1088s are present, along with the footswitch.

Serial number 19543 TB

Cabinet replaced, serial number plate original. Chassis number 12777. Woden mains transformer with date code "HW" = August 1965. In the preamp, red print WIMAs and Mullard mustard capacitors, the latter with visible date codes "B4N" and "D4N" = respectively second and last quarters of 1964.

Serial number 19575

Existence recorded by Jim Elyea

Serial number 19665 TB - currently in the UK

Top boost controls integrated in the panel. The cover is from a 1980s AC30.

Serial number 19666 TB

Top Boost controls in panel. In the preamp mostly Mullard mustards, though C6 and C9 are WIMAs. The Top Boost filter capacitor, certainly red, may be a CCL. Inside the cabinet, "Janet" is chalked - probably the lady who fitted it out for use with grille cloth, vinyl covering, handle, corner protectors, etc.

Serial number 19674 TB

Chassis produced by Burndept (number currently not known), Top Boost controls on control panel. Preamp in good original order, a mixture of WIMA and mustard signal capacitors (some date ?/64 - quarter unknown). The mains transformer is a Woden, date code either "HV" or "KV" - August or October 1964. Choke may be Woden too. The OT looks like an Albion. The cabinet has at present a pair of Celestion blues. Its grille cloth has been renewed.

Serial number 19810 TB - currently in Italy

Note the non-standard position of the logo - as on the AC30s issued to The Shadows in March 1961, and serial number 19820 (below) and the amp immediately below that.

Serial number 19820 TB - currently in Italy

Chassis number 11286. As in the case of serial number, the logo positioned high on the front. Thanks to Gigi for the pictures.

Serial number unknown - currently in the USA (?

Logo high up on the front, as on the two amps above.

Serial number 19858 TB

As above, Top boost controls integrated in the panel. The original runner designating the model is still present lower right on the grille cloth.

On to serial numbers in the 20000s and 21000s.

Back to serial numbers in the 17000s.