An early copper panel.

In early 1963, Tom Jennings began the process of trade-marking the design and name of the AC30 Twin, his best-selling and most "visible" amp, having already - in September 1961 - applied for a trade-mark for the Supertwin. Further details can be found on this page.

As in late 1962, JMI contracted out the assembly of AC30 chassis to Burndept Electronics in Erith and to Westrex in North London. Later, in early 1965, Jennings would move into Burndept's building in Erith - the "West Street Works".

A sure sign of production by Burndept is the presence of a stamped serial number on the chassis in front of the output transformer.

Detail of serial number 6097, below. Chassis numbers begin at 1000, but they 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. The earliest batches date from autumn '62.

Output transformer of serial number 6097. "66310" is the Jennings part number (for re-ordering). The transformers were specially made for JMI and do not figure in amps made by other makers. The date code is "JT" = September 1962.

The Woden part numbers were, in order: mains transformer no. 66309; output transformer no. 66310; and the choke no. 66311.

Other chassis were assembled for Vox by Westrex in North London (Dollis Hill). For certain batches of AC30, Westrex used dark brown 1/2 watt Dubilier resistors, rather than the white Eries employed by Burndept. Note their presence in serial number 6310, below. It is too early to say whether from time to time Westrex also used Wodens.

Cabinets were mostly beige, though there are some in smooth grey charcoal or dark grey pebble covering. Back boards should have square corners.

From May 1963, certain cabinets began to be fitted with the new plastic handles, the earliest known at present being those seen in a shot of the Rolling Stones, Battersea Park (11th May, 1963). Examples become numerous in the high 6000s, and then standard from the low 7000s.

One of the two AC30 Twins in black vinyl covering. Both have new-style plastic handles.

Speakers continue to be the Celestion blue (alnico magnet, Celestion part no. T530). As before, serial number plates are 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 can be found on this page.

The page on AC30s with serial numbers in the 5000s, is here; a new page on early Super Twins is available here.

If anyone knows of further early copper panel AC30s that should be incorporated on this page, do let me know.

Serial number 6000 N - currently in the USA

Excellent condition. Cabinet in beige vinyl. Chassis assembled by Westrex; Albion transformers. Red-print WIMA capacitors throughout the preamp. The Celestion blues have "RIC 2TP" cones.

NEW

Serial number 6006 N - currently in the UK

Chassis assembled by Westrex; Haddon transformers. Only one date code is known at present - in the preamp, the main TCC filter capacitor has "TH" = August 1962 for its manufacture. The original 82ohm cathode resistor is still present. One of the Celestion blues - non-original wiring in the speaker compartment - has the Pulsonic cone code "10H1777" - this page for the chronological sequence of these codes. "10H1777" means April 1963 or May/June 1964.

Updated

Serial number 6019 B - currently in the UK

The dual-spring tank in the foot of the case.

The defective tank and back panel assembly temporarily removed.

Recorded on this page as having Reverb. This however is likely to have been added later, perhaps at factory. A Top Boost unit was added at some other time. Thanks to Peter for the pictures.

Chassis assembled by Westrex, Haddon transformers. In the preamp, red-print WIMA signal caps, Mullard mustards added during an early service. The speakers are now late 1960s Celestion G12M ("Greenbacks"), Thames Ditton factory labels.

Serial number 602x N (?) - currently in Japan

After much indecision it seem best to leave the amp here. The first digit is difficult to make out properly - the bowl at bottom kicks out to the left like a "5" but the top curls over like a "6". All stamped "5"s - on this page - have flat tops. The main preamp filter capacitor appears to have the date code "UC" = March 1963 ("U" = 1963 is definite). The copper control panel is of the earliest type - "JMI" in relatively slender letters, "3" with a flat head, and "1" with a pronounced downward tick.

Serial number 6023 N - currently in the UK

Serial number 6027 - REPRO PLATE

Just to draw attention to a small clutch of repro serial number plates stamped (at some point in the last 10 or 20 years) with numbers in the 6000s - number 6207 below. See this page for more on these modern plates.

Repro plate stamped with non=original stamps. Note the lack of short lines under the "o" of "No."; the fatness of the letters in "Jennings Musical Industries Ltd"; and the placing and font of "A C Mains Only" and "115/255V 40-60 ~".

For comparison, the original plate of serial number 6000.

Serial number 6038 B - currently in the UK

Currently here. The main filter capacitor in the preamp - made by TCC - has the date code "UE" = May 1963. Note that the number "165" is incised by hand in the upright of the preamp above the speaker terminal block. "165" is also found written in crayon on the preamp of a later AC30 Super Twin.

Serial number 6041 B - currently in the UK

The number on the serial plate said to be 6041B. The grey panel chassis is certainly later, perhaps the box too with its corner protectors.

Serial number 6045 - currently in the USA

Existence reported by Jim Elyea.

Serial number 6056 B - currently in the UK

A Super Twin, the speaker cabinet now with later silver Celestion T1088 speakers (lacking VOX labels). Both cabinets are covered in the same heavy lightly patterned black vynide. The BASS flag on the amplifier section section is directly underneath the VOX logo, as on a number of other Super Twins from 1963.

Serial number 6097 N - currently in the USA

Note that the back boards have rounded corners. The date codes on the Celestions are "31KG" and "08LG" = 31st October and 8th November 1962. Date codes on the Woden transformers are "HT" and "JT" = August and September 1962. One of the blue Hunts bypass capacitors in the preamp has the date code "HHH" = 22nd week of 1962. The chassis is number 01125.

Serial number 609x N - currently in Japan

The chassis, assembled by Burndept, is not original to the box. Chassis number 02266 (or 2286). The Woden transformers have the date code "KU" = October 1963.

Serial number 6102 N - currently in the UK

Chassis assembled by Burndept - number 01624. The Woden output transformer and choke have the date code "AU" = January 1963 and the mains transformer "BU" = February 1963. The cabinet, stripped and now part redone, only has holes for new-style plastic handles (repros currently). There are no signs of any holes for the longer strap handles. The cabinet also has holes for swivel side stands. The Celestion blues have Pulsonic cones with code "71H1777" = December 1962 or January 1963 for their manufacture.

Serial number 6117 N - currently in the USA

Good external condition; the cover may be the original. Chassis assembled by Westrex. Transformers are Haddons (not Albions as previously stated). One of the pots has the date code "JJ" = October 1962.

Serial number 6121 N - currently in the UK

Recently sold, AC30 Twin serial number 6121N, early 1963. Original beige vinyl and probably the original Celestion blues, the left hand one having been taken out at some time and put back in at 90 degrees to the norm. The two end handles are replacements.

Serial number 6172 N - currently in the UK

Currently here. Covering originally beige. Original Woden transformers in place, date code "LT" = November 1962.

Serial number 6210 - currently in the USA

Existence reported by Jim Elyea.

Serial number 6283 B - currently in Europe

Albion transformers. Good electronic condition. The main TCC filter cap has the date code "TM" = December 1962; and one of the blue Hunts cathode bypass caps has "HUH" = 26th week of 1962. The control panel is of the earliest copper type with "JMI" in fine letters.

Serial number 6310 N - currently in Australia

Mains transformer and choke are Haddons, the output transformer Albion. One of the blue Hunts capacitors in the preamp has the date code "HUH" = 26th week of 1962. A TCC capacitor has the code "TJ" = September 1962.

Serial number 6313 - currently in the USA

An AC30 Super Twin. See also this page.

Serial number 6364 B - currently in South Africa

Bags of character in this one. Chassis assembled by Westrex. The original Celestion blues are in place: date codes 04MG and 18MG = 4th and 18th December, 1962. Thanks to Nick for the pictures.

Serial number 6372 N - currently in the UK

Dimpled black vinyl; leather handles. Chassis assembled by Westrex. Albion Transformers. In the preamp, WIMA signal caps; a mixture of brown Dubilier and white Erie resistors. The main preamp filter cap has the date code "TM" = December 1962. One of the pots has "KJ" = November 1962. The Celestion blues have "18MG on their gaskets = 18th December, 1962, for their manufacture.

Serial number 6424 B - currently in Spain

Beige/fawn cabinet in excellent condition. The original Celestion blues look to be in place. Nothing known about the electronics of the chassis.

Serial number 6390 - currently in the USA

Existence reported by Jim Elyea.

Serial number 6408 - REPRO PLATE

See the entry for serial number 6207 above.

Serial number 6424 B - currently in Spain

Serial number 6430 N

Chassis assembled by Burndept, number 01263. Woden transformers and choke: date code "LT" = November 1962 for their manufacture. In the preamp, the pots have: "JJ" and "LJ" = October and December 1962. The cabinet still has its original fixtures and fittings. Thanks to Glen for the pictures.

Serial number 643x (later chassis in modified early cabinet) - currently in Japan

The cabinet, speakers and serial number plate are from mid 1963. The cabinet back-boards have square edges. Two-pin corner protectors, and late 1960s vents have been added however. The date codes of the Celestion blue speakers are "23GH" and "26GH", respectively 23rd and 26th July 1963. The chassis is later - from mid 1964. The preamp has Mullard mustard capacitors; the Albion transformers have post-63 paper labels; the TCC capacitors have the date code "VC" = March 1964; the value of the cathode resistor is 47R, the change from 80R (often in practice 82R) to 50R (in practice often 47R) having come in late 1963. The footswitch is of the later type too.

Serial number 6443 B - currently in Australia

Original smooth black vinyl covering on the cabinet. Square corners to the backboards. The corner protectors are later additions. Chassis produced by Westrex; Albion transformers. Underchassis, the cathode resistor is 82ohms;, the Hunts 32uf capacitor has the date code "WYW" = 10th week of 1961. In the preamp, the main TCC preamp filter capacitor has "TM" = December 1962. On the underchassis, near the underside of the output transformer, is what may be the Westrex inspection stamp. Thanks to Glen for the pictures.

Serial number 6529 N - currently in the UK

The cabinet now divided in two. Smooth grey covering. Woden transformers, date codes unfortunately not visible. Further pictures here.

Serial number in the 6000s

Chassis assembled by Burndept, number 01329. The Woden transformers and choke have the date code "LT" = November 1962. In the preamp, WIMA Tropyfol capacitors. One of the blue Hunts bypass caps has the date code "THH", and the main preamp filter "TSH" = 42nd and 45th week 1962. The cabinet was recovered in basketweave in the 1990s/2000s. The speakers have date codes for 11th and 15th January 1963. Thanks to Nick for the pictures.

Serial number 6534 N

Chassis number 01381; produced by Burndept. Sold in the UK, November 2020. Dimpled black vinyl; brass vents; square corners to the back boards; ribbed black plastic handles with old style fixings. The Woden transformers have date codes "LT" and "MT" = November and December 1962. The original speakers are still in place, the date code on both being "31AH" = 31st January 1963.

Serial number 6562 - currently in the UK

Simply the cabinet with various elements added (double pin corner protectors for instance) and the serial number plate.

Serial number 6590 - currently in the USA

Existence reported by Jim Elyea.

Serial number 6634 N (?) - currently in the UK

The serial number plate sold on ebay some time ago. Not 6534 as that amp is now known to exist with its original plate (Nov. 2020)

Serial number 6639 N - currently in the UK

Black pebble covering. Probably the original Celestion blues in place.

NEW

Serial number 6649 N

Chassis assembled by Westrex. Volume pots with date code "AK" = January 1963, tone pot with "LJ" = December 1962. The Celestion blues have "28BH" = 28th February, 1963 for their manufacture. In the power section, the original Welwyn 82ohm cathode resistor is still in place. The cabinet is covered in finely textured black vinyl (Morocco); leather handles; original round footswitch present. Thanks to Glen for the info.

Serial number 6664N - currently in the UK

Chassis assembled by Burndept. The cabinet is original (square corners to the back boards) but with some changes and additions (corner protectors and black vents). The Woden mains transformer and choke have the date code "HT" = August 1962. The main preamp filter cap, slightly difficult to read, seems either to have the date code "ITH" = 34th week of 1962, or "IHI" 23rd week of 1963. The speakers are now Celestion T1088s, replacing the original blues. Thanks to Andy for the pictures.

Serial number 6715 B - currently in Europe

Assembled by Westrex. Albion transformers. The cabinet is covered with black smooth pebble charcoal covering.

Woden Transformers

In AC30s assembled for JMI by Burndept, one begins to see Woden transformers with "AU" date codes = January 1963 from this point. Remember that this is simply the date of their manufacture, not the date of their use, or the date of the AC30 as a whole. Note that the chassis in the cabinet with serial number plate 6102 (near the top of this page) is not original to it.

Serial number 6716 - currently in the UK

A Super Twin amplifier set. Smooth black vinyl. Plastic corner protectors on the cabinets. Chassis assembled by Burndept. Woden transformers with "AU" date codes = January 1963. Other components have late 1962 and early 1963 date codes. Note the new-style plastic handle on the amplifier section.

Serial number 6731 N - currently in the USA

Smooth charcoal vinyl. Leather handles on the cabinet.

Serial number 6763 N - currently in the USA

Serial number 6788 B - currently in Holland

Black dimpled vinyl (possibly painted over at some point and cleaned off later). New style plastic handles. Square corners to the back boards of the cabinet. Original blue Celestions in place.

Serial number 6792 N - currently in the USA

Replaced grille cloth and speakers. The box and chassis look to be original - note the fine dark charcoal pebble vinyl of the cabinet.

Serial number 6804 N - currently in Europe

Assembled by Westrex. Probably Albion transformers. Brown Dubilier resistors in the preamp.

Serial number 6805 - currently in the USA

Existence reported by Jim Elyea.

Serial number 6822 B - currently in Europe

Recovered (?) in dimpled black and red vinyl. The vinyl of the bottom back board is different. Note that no holes for the outer two handles on top of the amp are visible. Piping and corner protectors are later additions. One of the pots has the date code "LJ" = December 1962. A gold-coloured TCC cathode bypass capacitor in the preamp has "TJ" = September 1962.

Serial number 6832 - REPRO PLATE

See the entry for serial number 6207 above, and this page for more on these modern plates.

Serial number 6840 N - currently in the UK

Original beige. A replaced mains transformer, and silicon rectifer diodes instead of the valve. On the 50ohm cathode bias resistor the date code "UJ" = September 1963.

Serial number 6855 - currently in the UK

AC30 Super Twin amplifier section 6855 (Normal), paired with a slightly later Foundation Bass speaker cabinet (18" driver). The amp has been recovered, and regrilled to match the regrilled speaker cabinet. Thanks to Tessa for the pictures.

Serial number 6855 - currently in the UK

An AC30 Super Twin - see this page.

Serial number 6873 N - currently in the UK

Smooth black vinyl, plastic SBU handles. The original footswitch is still present. As can be seen, the amp has been well used and is still in superb working order. Thanks to Mark for the pictures.

Serial number 6887 B - currently in the UK

Chassis assembled by Westrex; Albion transformers. Saved from being chucked away when a former dance hall in Birmingham was being cleared out in the late sixties / early seventies. The Celestion T530s have the date code "03DH" = 3rd April 1963 - suggesting that the amp was ready for sale in May/June of that year. Thanks to Simon for the pictures.

Serial number 6890 N

Chassis assembled by Westrex; Albion transformers. Cabinet covered with pebble vinyl. The Celestion blues have the date code "09DH" = 9th April 1963 for their manufacture. The original footswitch still present.

Serial number 6893 B - currently in the UK

Chassis made by Westrex. Albion transformers. Square corners to the back boards. The amp was probably sent back to Dartford Road for refurbishing in mid 1964 - the date codes of the two Celestions are of March 1964. It was then acquired / received from JMI by a Vox demonstrator, so may have been a demonstration amp from the beginning. Thanks to Andy for the pictures.

Serial number 6898 B - currently in the USA

Sold by Heritage Auctions in early 2020. The cabinet, with its basketweave covering and back boards with rounded corners (which come in around serial number 7400), is later. New double-pin corner protectors have been added to the upper corners, front and back. Handles and vents look to be replacements. Whether the chassis goes with the serial number is unknown - perhaps it does.

Serial number 6920 N - currently in the UK

Black "pebble" or "dimpled" vinyl, leather handles. The transformers are Albions. One of the blue Hunts capacitors in the preamp has the date code "T HH" = 42nd week of 1962 = 15th-19th October, assuming that the Hunts factory was closed on Saturdays. A number of the original Mullard white-print ECC83s have the print date code "KA" = January 1963; one of the EL84s has "B2K2" = 2nd week of November 1962.

Serial number 6928 B - currently in the UK

Black dimpled vinyl, leather handles, speakers with April 1963 date codes. Thanks to Bill for the pic. and info.

Serial number 6929 B - currently in Japan

Cabinet covered with black smooth pebble charcoal covering. Top boost added on the back panel. Transformers are Albions.

Serial number 6932 N - currently in the USA

Original red vinyl.

Serial number 6947 N - currently in the UK

Serial number 6948 N - currently in the UK

Black dimpled vinyl; brass vents; square corners to the back boards. Factory fitted top boost. The Woden transformers and choke have the date code "AU" = January 1963. One of the potentiometers is dated "AK" = Jan. '63 also. The code on the treble pot of the top boost unit ends "K" = 1963. What look to be the original Celestion blues are in place.

Serial number 6950 N - currently in the USA

The cabinet has new style plastic handles.

SERIAL NUMBERS UNKNOWN

Serial number unknown - currently in the UK

With its original red cover. Woden transformer date code "LT" = November 1962. Celestion date code "13MG" = 13th December 1962.

Serial number unknown - currently in the UK

"Normal" voicing. Serial number plate lacking. The Woden transformers have date codes "LT" = November 1962 and the pots have "JJ" = October 1962. The chassis, assembled by Burndept for Vox, is number 01353.

On to the next page - serial numbers in the 7000s.

Back to - serial numbers in the 5000s.