Vox AC30: copper panels

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 is the presence of Albion tranformers. Dark brown Dubilier resistors are found along with white Eries.

Cabinets are for the most part 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.

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

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 12019 - currently in the UK

Chassis number 04690. Albion transformers. A mixture of Mullard mustard and WIMA capacitors in the preamp. The Mullards have date codes "D3N" and "A4N", respectively last quarter of 1963 and first quarter of 1964. Grey panel with integrated top boost.

Serial number 12022 T

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

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 12300

Existence noted by Jim Elyea.

Serial number 12501 N - currently in Europe

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 12543 - currently in Europe

Basketweave vinyl. Currently .

Serial number 12549 - currently in Europe

Thick smooth dark grey vinyl. Currently .

Serial number 12588 TB - currently in the UK

Top Boost in panel. The cabinet has pebble (dimpled) vinyl. Thanks to Malcolm for the photo.

NEW

Serial number 12589 TB - currently in the UK

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.

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.

Serial number 12733

Thick smooth dark grey vinyl.

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.

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