Vox AC30: copper panels

(and some early grey)

Early to mid 1964: serial numbers in the 12000s

Serial number 12733 Treble, the plate still hand stamped.

Continued from the page on AC30s with . Also encompassed below, Super Twins with numbers in the main AC30 sequence - Super Twins (and Super Twin Reverbs) by this point had a sequence of their own beginning at .

A good number of amps were apparently covered in thick, smoooth dark grey vinyl.

Throughout the 12000s one finds three models: the "Treble", designated with a "T" on its serial number plate; "Normal" voicing designated by an "N", and Bass designated "B". All three had their own schematics, in order: OS/056, OS/065 and OS/057. Some notes on the treble circuit, which was new in 1964, can be found .

Documents relating to the AC30 in 1964 are being assembled .

Vox contracted out the assembly of AC30 chassis to two companies: Burndept Electronics in Erith, and Westrex in Dollis Hill (north London). A sure sign of production by Burndept is the presence of a stamped serial number on the aluminium upright of the preamp chassis (normally on the right hand side a little way below the voltage selector):

Detail of serial number 9916. Chassis number 02607. The chassis number sequence began at 1000, but chassis awaiting assembly were not used in any particular order.

Also indicative of production by Burndept at this stage is the presence of Woden transformers with handsome green shrouds. Serial numbers in the 11000s (much as those in the 10000s) have date codes for late 1963 - "JU", "KU" and "MU" = September, October and December 1963; and early 1964 - "AV" and "BV", respectively January and February. JMI evidently ordered sizeable batches:

Serial number 12004 - output transformer date code is "AV" = January 1964; the choke has "BV" = February 1964.

The Woden part numbers were, in order: mains transformer 72318; output transformer no. 66310; and the choke no. 66311.

A good indication that a chassis was assembled by Westrex at this point in production is the presence of Albion transformers. Burndept adopted Albions a little later on (in the 13000s) along with Parmekos (in the 14000s). Dark brown 1/2 watt Dubilier resistors were used by both sub-contractors, Burndept gradually moving away from the white Eries it had used previously.

From early 1964, most Twins have Burndept-made chassis; those produced by Westrex were generally alloted to Super Twins.

Cabinets are in the main covered in black basketweave vinyl, though "pebble" ("dimpled") vinyl was evidently used from time to time, and likewise smooth black or charcoal vinyl. Back boards as a rule now have radiused corners rather than square.

Speakers in "standard" AC30s continue to be the Celestion blue (alnico magnet, Celestion part no. T530) - date codes in mid 1964, the final "H" in the code can indicate 1963 or 1964. The preceding letter is always the month (A-L).

Serial number plates are still hand stamped.

Where component date codes are concerned, speakers consistently have the latest - i.e. later than any of those on the electronic components used in chassis. An overview of AC30s with dated speakers .

The page on AC30s with serial numbers in the 10000s, , and the page on serial numbers in the .

If anyone knows of further AC30s that should be incorporated on this page, .

Serial number 12004 - currently in Europe

Chassis assembled by Burndept. Copper panel; smooth dark grey pebble (dimpled) vinyl. Date codes of the Woden transformers are "AV" = January 1964, and the choke "BV" = February 1964.

Serial number 12010 T - currently in the UK

Chassis assembled by Burndept, number 02956. Copper panel. Woden mains transformer date code "MU" = December 1963; the Woden output "JU" = September '63. in the preamp, red and black print WIMA signal caps; the main Hunts filter cap has "TDI" = 48th week '63. One of the Celestion blues has the date code "03CJ" for its manufacture = 3rd March, 1964. The cabinet is covered with dark grey lightly textured vinyl. Thanks to Kev for the pictures.

Serial number 12011 T - currently in the UK

Serial number 12019 - currently in the UK

Chassis assembled by Burndept, number 04690. Albion transformers. A mixture of Mullard mustard and WIMA capacitors in the preamp. The Mullards have date codes "D3N", "A4N" and "14N" = last quarter of 1963, and first quarter of 1964. Grey panel with integrated Top Boost. The stamping on the serial number plate (which looks genuine enough - i.e. not a repro) is unusually shaky.

Update, 2024 The chassis has now been given a reproduction copper control panel and forms part of a concocted Expanded Frequency AC30 sold in the UK in 2021.

Serial number 12022 T

Simply the plate, evidently detached from the amp some time ago.

Serial number 12028 T - currently in the UK

Sold in Manchester - by J. Reno and Co. Ltd (Oxford Street) - in late May 1964. Total hire purchase price was £156 and 5 shillings - a deposit of £31 and 5 shillings and 100 weekly payments of £1 and 5 shillings were envisaged. Initial payment made on 27th May 1964, the next "the first rental" due on 3rd June. Eleven payments were made of varying amounts through to early November 1964, at which point the amp had been paid for.

Serial number 12069 T - currently in the USA

Existence known from a picture of the serial number plate.

Serial number 12093 B

Broken up. Chassis assembled by Westrex; Albion transformers. Serial number plate sold on its own on ebay in the UK, May 2024. One of the speakers belonging to the amp appears to have had the date code "22DJ" = 22nd April 1964.

Serial number 12104 B

Chassis assembled by Burndept; chassis number 03749; BASS voicing. The Woden transformers have "AV" date codes: January 1964. The choke has "BV" = February 1964. In the preamp, red-print WIMA signal capacitors. The main preamp filter, made by Hunts, has "TDI" = 48th week of 1963 for its manufacture.

Serial number 12123 B

Serial number 12158 B

A serial number plate, detached from its cabinet.

Serial number 12238 N - currently in the USA

Existence known from an old "Plexi Palace" forum thread. The amp was described as having a copper panel and integral Top Boost.

Serial number 12290 B

Chassis assembled by Burndept. Woden transformers with "KU" and "LU" date codes, respectively October and November 1963 for their manufacture. Cabinet grille cloth renewed, double-pin corner protectors added.

Serial number 12242 B - currently in Canada

A great clean AC30. Chassis assembled by Westrex. Albion transformers; WIMA capacitors in the preamp. The cabinet, with its chipboard baffle and chalked numbers, was produced for JMI by Gla-Rev. The Celestion blues have date codes "18BJ and "20BJ" = 18th and 20th February 1964. Thanks to Shaun for the pictures.

Serial number 12247L - currently in Europe

A "Transistor Lightweight 30" - effectively a T60 chassis in a square-ish cabinet fitted with three 10" speakers. A further example with a serial number in the main AC30 sequence is 13939L. Earlier amps had numbers in the T60 sequence.

Serial number 12253 (?) - currently in the UK

Chassis number 04866, now in a later cabinet. Although the serial number plate is a repro, it may carry the amp's original number - 12253. The chassis certainly belongs in the 12000s. Visible in the preamp are mustard capacitors with the date code "A/64" = first quarter of 1964. The transformers are Albions. Thanks to Michael for the pictures.

Serial number 12300

Existence noted by Jim Elyea.

Serial number 12333 B - currently in Italy

A Super Twin, amplifier section and speaker cabinet, the BASS flag still present on the front grille.

Serial number 12374 L

A Vox AC30 Transistor Lightweight, three Elac 10N/82s (in Jennings blue) wired in series for a total impedance of around 11-12 ohms. Note that the amplifier section, effectively a T60 bass chassis with an added transistorised tremolo module, has a black panel, normally found on early units (late 1962 and 1963) - so probably old stock taken up for use in 1964. Also part of the main AC30 Twin sequence, Lightweight Serial number 13939L - .

NEW

Serial number 12395 N

A Super Twin amplifier section. Chassis assembled by Westrex. In the preamp, red-print WIMA signal caps and gold-coloured TCC cathode bypass caps. The grille cloth has since been replaced with cloth from some other amp.

Serial number 12405 TB - currently in the UK

Grey panel with integrated Top Boost controls. The cabinet covered with thick grey vinyl. Double pin corner protectors added later.

Serial number 12411 TB - currently in Europe

Chassis number 04551. Assembled by Burndept. Grey panel, integrated Top Boost. Albion transformers. One of the Mullard mustard capacitors has the date code "D3" = last quarter of 1963; and another has "A/64" = January 1964.

NEW

Serial number 12423 T (?)

The serial number plate is a reproduction. "Jennings Musical Industries Ltd." and "Warning" are too spindly; the number is stamped with non-original stamps. Chassis assembled by Burndept. The Woden output transformer appears to have "JU" = October 1963. The choke has "MU" = December 1963. The main filter cap in the preamp, made by Hunts, has "TDI" = 48th week of 1963 for its manufacture.

Serial number 12440 TB - currently in the UK

Chassis made by Burndept. Top Boost controls in grey control panel. Smooth dark grey textured vinyl; black metal vents.

Serial number 12501 N - currently in Europe

Chassis assembled by Westrex (most Westrex-made chassis were allocated to Super Twins) and stamped at left in purple "Westrex Treble". Whether this really is a treble model is unknown. The serial number plate gives "N" as the voicing. The Woden mains transformer, likely to be a later replacement, has the date code "EW" = May 1965.

NEW

Serial number 12542 B

Currently in Holland. Thanks to Peter for the info.

Serial number 12543 B - currently in Europe

Chassis assembled by Burndept. Basketweave vinyl. Currently .

Serial number 12549 - currently in Europe

Thick smooth dark grey vinyl. Currently .

Serial number 12554 B - currently in the UK

Dark grey finely textured vinyl. Chassis assembled by Burndept, number 04291. Albion transformers. In the preamp, Mullard mustard capacitors date codes for the last quarter of 1963 and first quarter of 1964. One of the yellow-print Mullard preamp valves is still in place, paint code for 1964, month unknown.

Serial number 12558 B - currently in the UK

Chassis assembled by Burndept, number 04xxx. "BASS" stamped in red in the preamp. Copper panel; Albion transformers. In the preamp, a mix of WIMA and Mullard mustard capacitors, the latter with date codes D3N" and "14N", respectively third quarter of 1963 and first quarter of 1964 for their manufacture. The tone cut pot has the date "AL" = January 1964. An ink-stamped "B" in a circle ("B" for Burndept) can be seen on the preamp upright near the main filter cap. The cabinet has dark grey textured vinyl and now double-pin corner protectors.

Serial number 12563 N - currently in the UK

Sold on ebay some time ago - an AC30 serving as a PA amplifier with two LS40 speaker columns.

Serial number 12569 N - currently in the UK

Basketweave vinyl. A rare instance of a copper panel Twin with integral Top Boost (bass and treble) controls. Chassis assembled by Westrex; Albion transformers. The choke may be a replacement, its sticker stuck to the output transformer. One of the gold-coloured TCC cathode bypass caps in the preamp has the date code "UF" = June 1963. Inscribed above the speaker output block is the number "165", which is found on other chassis assembled by Westrex (an AC80/100 and two other AC30s). Thanks to Ben for the pictures.

Serial number 12588 TB - currently in the UK

Top Boost in panel. The cabinet has dark grey textured vinyl. Thanks to Malcolm for the photo.

Serial number 12589 TB - currently in the UK

Chassis assembled by Burndept. Grey panel, top boost controls integrated. The JMI logo on the panel is standard format, not as the one on serial number 12019 (above). Transformers are Albions. Mullard mustard capacitors in the preamp have the date codes "D3N" and "14N" = last quarter of 1963 and first quarter of 1964.

NEW

Serial number 12613 TB

The serial number plate gives "Top Boost" but the chassis is a Bass model, "BASS" stamped in blue in the preamp. Chassis assembled by Burndept. Woden output transformer with "AV" = January 1964; choke with "BV" = Feb. '64. The mains transformer is an Albion. The original blues look to be in place. An original Vox cover - light/mid brown, no logo - accompanies.

Serial number 12622 TB - currently in the UK

Smooth dark grey textured vinyl. Top boost integrated in the control panel. Complete with footswitch and original maroon cover. Thanks to Jeremy for the pictures.

Serial number 12635 N - currently in Europe

An instance of a Super Twin with a number that would normally be reserved for a Twin. The voicing is given as Normal ("N"). The cab was said to contain "silver bulldog" speakers - ie. Celestion T1088s.

NEW

Serial number 12726 T

A chassis, with Top Boost added on the back panel, in a Super Twin amplifier section box. The chassis - number 8197 - is stamped "TREBLE" in red. Visible Mullard capacitors have "B/64" date codes = second quarter of 1964. The chassis number seems uncommonly high. Most chassis on this page have numbers in the 4000s. Within a particular serial number range these numbers can differ - certainly by as much as 1000 or 2000. A disparity of 4000 seems a little unusual. The steel chassis plinth (and transformers) have been sandblasted.

Serial number 12731 T - currently in the UK

Chassis assembled by Westrex; Albion transformers. A Treble model - coupling caps are 0.047uf. In the preamp, WIMA Tropyfols throughout, gold-coloured TCC cathode bypass capacitors. One of the latter has the date code "UM" = December 1963.

Serial number 12733

Thick smooth dark grey vinyl.

Serial number 12740 T - currently in Ceredigion

Chassis assembled by Westrex, a stamp in the preamp at left: "Westrex Treble". Copper control panel. One of the Celestion blues (T530) has the date code "10DJ" = 10th April 1964. The cabinet has smooth grey textured vinyl. Thanks to Owen for the pictures.

Updated

Serial number 12744 T - currently in the UK

Cabinet covered in textured dark grey vinyl. Chassis assembled by Westrex. Woden transformers: mains with "LT" = November 1962!, output and choke with "KU" = October 1963. The tone pot has "LJ" = December 1963. The main coupling caps are 0.15uf, so this is not a Treble chassis (nor is it stamped as such). The cabinet has square corners to its back boards. One would expect to find this in an amp that had a full set of Wodens from Nov. 1962 certainly, but not in an amp produced (made ready for sale) in 1964. The two cabinet handles have no logo in the lozenge-shaped central panel.

NEW

Serial number 12775 B

The chassis is now in a later slope-sided AC30 Super Twin cabinet.

Serial number 12784 T - currently in Europe

Chassis number 03401, assembled by Burndept. WIMA and Hunts caps in the preamp. The Woden transformers have the date code "AV" = January 1964. The Celestion blues have "24JC" and "25JC" = 24th and 25th of March 1964. The letters of the code have been given in reverse order, an occasional Celestion foible. They should be "CJ".

Serial number 12787 B - currently in Europe

Chassis number 04851, assembled by Burndept. The Mullard mustard capacitors have date codes "A/64" and "B/64" = first and second quarters of 1964. Thick smooth dark grey vinyl on the cabinet. Corner protectors added later.

Serial number 12806 N - currently in the UK

Thanks to Joanna, shots of an AC30 formerly belonging to Tony McPhee of "The Groundhogs" - cabinet, with serial number 12086N, recovered and regrilled; the chassis, copper panel with integrated Top Boost controls.

Serial number 12850

Existence noted by Jim Elyea.

Serial number 12xxx N - currently in Japan

Another Super Twin, normal voicing. Transformers are Albions. The chassis is likely to have been assembled by Westrex.

Serial number 12864 B - currently in the UK

A Super Twin. Chassis assembled for JMI by Westrex. The serial number plate is stamped "B" for Bass, but the chassis is a "Treble", stamped in bluish-purple at left. The main preamp filter cap has the date code "UJ" = September 1963 for its manufacture. The speakers have been replaced.

Serial number 12907 N - currently in the UK

A Super Twin. Copper panel; Albion transformers. The Celestion blues in the separate speaker cabinet have date code "25BJ" = 25th February 1964. The right-hand speaker has been rotated in recent times.

Serial number 12953 B - currently in the UK

December 2024: broken up for sale in bits. Cabinet and serial number plate (with distinctive damage) below:

Serial numbers unknown

Currently in the UK

Chassis assembled by Burndept. Bass voicing. Copper panel; Albion transformers. In the preamp, a mix of WIMA and Mullard mustard capacitors - date codes of the latter "D3N" and "14N" = third quarter of 1963 and first quarter of 1964. The Celestion blue speakers are dated "13BJ" = 13th February 1964. The cabinet is finished in basketweave vinyl.

Currently in the UK

The position of this amp here is tenuous. It could on the face of things be an early grey panel. Transformers are Albions. The TCC cathode bypass capacitors in the preamp have the date code "UC" = March 1963. The chassis, unusually for a Twin, was assembled by Westrex. It may be necessary to move this entry in due course.

Currently in the USA

Chassis number 04530. Dimpled dark grey vinyl. Double in corner protectors added. The chassis is grey panel with integral top boost. Visible Mullard mustard capacitors in the preamp have the date code "14N" = first quarter of 1964. One of the original speakers has been replaced with a modern Celestion blue.

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