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.

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 18016 TB

Exterior shots only.

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 1813x TB

Exterior shots only. Original footswitch and cover present.

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.

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).

Updated

Serial number 18513 TB

Albion or Parmeko transformers; link voltage selector. Original speakers still in place (terminals 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.

Updated

Serial number 18661 T - currently in the

Chassis assembled by Westrex, Albion transformers. In the preamp, mainly WIMA signal capacitors. The silver celestions have cones with Pulsonic code 7H1777, likely to mean February/March 1965.

Serial number 18695 T - currently in Europe

Exterior shots only. A rectangular hole and stencil on the upper back panel.

Updated

Serial number 18715 - currently in the UK

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

NEW

Serial number 18744 TB - currently in Italy

Chassis number 10669. Woden transformers with date codes "JV" and "KV" = September and October 1964 for their manufacture. In the preamp, Mullard mustards with "B4N" and "C/64" = second and third quarters of 1964. The original speakers and footswitch are present. Thanks to Giovanni for the pictures.

Updated

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 18789 TB - currently in Canada

Thanks to Rob for info on the existence of the amp.

NEW

Serial number 18819 TB - currently in Europe

Serial number 18900 - currently in the USA

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

NEW

Serial number 18908 T - currently in Europe

Exported to Scandinavia early on; voltage selector removed and additional fuses added internally. Chassis produced by Westrex and stamped "T" on the left-hand side. Albion (?) transformers. The original silver Celestion speakers look to be in place.

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.

On to serial numbers in the 20000s.

Back to serial numbers in the 17000s.