AC100 mark 2s - late 1965
Amps conforming to the "AC 100/2" schematic
As on the previous page - serial numbers 730-899 - note the presence of the brimistor, and the use still of the two-line serial number plate. A metal guard around the valves comes in at the end of 1965.
Production of these amps at the Vox / Burndept works on West Street, Erith, was consistent. The main filter capacitors in both power amp and preamp are TCCs (Telegraph Condenser Company - see this page). At the end of 1965, blue Hunts caps. make their appearance in the preamp.
The warning plaque on the back panel is red (its colour having been changed from the older white with the introduction of the brimistor).
Serial number in the 900s - currently in the USA
Chassis number 1656. The original serial number plate is missing. General condition of the amp is good. The output transformer may, however, be a replacement. It is not known at present how the amp comes to have an original copper panel.
Serial number 902 - currently in the USA (collection: Mark Vaquer)
Another great amp. A single speaker output, as in the case of no. 825, and the amp below (no. 966?). Woden choke code FW? = June 1965.
Serial number 917 - currently in the USA?
Sold on ebay in 2008. Chassis number 1497. An amp in good general condition with brimistor still in place. The power transformer has the code 66775, but there are no markings on the output. A bias (?) transformer has been added on the upper chassis. On the back panel: a single speaker output and a white warning plaque, top left.
Serial number 936 - currently in Holland
Currently in Holland - a fine bass rig.
Serial number 966? - currently in the USA
Despite the good original pictures, it's hard to make out what the serial number is. 966 seems likely both from the inverted image, and from the presence of a mains switch with two "flanges" top and bottom. A switch of this kind appears on an amp with a number probably in the 1100s (below), but not on earlier examples. Two Amphenol sockets on the back panel.
Serial number 987 - currently in the USA (collection: Gary Hahlbeck)
Reproduced by kind permission of Gary Hahlbeck
Part of the extensive collection owned by North Coast Music. The mains input socket is a later Switchcraft (note the flat profile). The twin speaker output sockets are Amphenols.
Serial number 994 - currently in Germany
Serial number 900-1000s? - currently in the USA
Sold on ebay in 2008 - good pictures. The amp has no serial plate, and the chassis number is tantalisingly difficult to make out - 14xx? Various modifications have been made to the amp: most obviously, new grille cloth, and on the underside a small transformer, network and pots for generating a variable bias. The original Hunts/TCC capacitors remain in the preamp. The Woden choke has the code HW = August 1965.
Serial number in the 1000s - currently in the USA (collection: Marc Speed)
Chassis number 1705. No serial number plate. Renewed grille cloth.
Serial number 1064 - currently in Australia
Chassis number 1772. Pictured with a Supreme cabinet with Goodmans Power Range speakers - an impressive sight. Double speaker output XLRs, with original Amphenols still in place, as serial no. 987 above. Note the blue numbered sticker, as no. 1090 below. Thanks to Warren for the pictures.
Serial number 1067 - currently in the Netherlands?
In good cosmetic condition. Note the addition of a "BASS" flag from a 2x15 cabinet. What looks like a standby switch has also been added.
Serial number 1071 - currently in the USA
Made by Triumph for Vox. Considerably later than the other amps on this page, and simply here for reference. Triumph brought together chassis, boxes and serial number plates in an entirely random way. For further images, see this page.
Serial number 1072 - currently in the Netherlands
A fine AC100 with its original 2 x 15" cabinet. A few small changes here and there - the most notable of which is a preamp line out - but nothing major. Original Amphenol speaker output socket and red warning plaque on the back panel. Thanks to Tom for the pictures.
Serial number 1079 - currently in the Netherlands
With its original 2 x 15" bass cab (as no. 1072 above). Thanks to Mees for the pictures.
Serial number 1090 - currently in Australia
Chassis number 1769. Pictured with a Vox 2 x 15" cab bearing a Jennings Electronic Industries Sticker (model B2). The blue numbered stickers (as 1064 above) on amp and cab bring Germany in view - the legend on the cab reads "2x15 Goodmanns [sic] a. 8ohm in Reihe". Original XLR speaker and mains connectors. Thanks to Warren for the pictures.
Serial number 1099 - currently in the UK
Serial number 1099, chassis number 1762. Arrived in a pretty parlous condition, almost as if it had been smothered with marmalade and put in an understairs cupboard for twenty years. The poor old thing had at one stage been converted into a two channel amp, possibly for some special purpose, as the gain had been drastically curtailed. The valve complement was peculiar too - two GEC KT77s and two Mullard EL34s. The box, however, had been nicely fitted out with spangly cloth. She now works well, and has a fancy repro copper panel. Capacitors have codes for December 1964, April 1965 and May 1965. The Woden choke has the code HW = August 1965.
Pictures 6-10 show the original state of the power section; 11 shows the original choke in place, but new filter capacitors beside it; 12-17 shows the beginning of testing, getting the amp working with new capacitors in the preamp and a temporary replacement choke (the hum from the twin-channel circuit was colossal) - the temporary replacement choke came from ser. no. 1980; pictures 18-20 show the present state of the amp - further images to be supplied.
The original control panel reinstated, rubber stoppers to fill the holes that had been made. Erie resistors added to the input jacks; and the dreadful replacement white preamp sockets replaced in turn by McMurdos. The original Zener diodes - 20v and 15v - have been put aside with other removed parts in favour of two diodes totallying 39v (21v and 18v).
Serial number 1111 - currently in the UK
Recently sold on ebay. Replacement output transformer and choke, and sympathetically restored power board. Good working order.
Serial number 1115 - currently in the UK
Sold on ebay UK, July 2015. Two line plate; brimistor; a pair of Amphenol speaker XLRs. Note that the leads from the output transformer curl round the chassis rather than pass through the hole provided directly behind it.
Serial number 1153 - currently in Italy
Nicely restored. Original transformers, choke and hardware. Date code of the choke is "HW" = August 1965.
Serial number in the 1100s? - box with serial plate 1884 - currently in the UK
Box with serial number plate 1884. But the amp is much earlier. Chassis no. 1764; grid resistors on flying leads in the preamp; and Wima signal capacitors. A small transformer has been added to produce the bias voltage for the EL34s. The amp was originally used by the girl group "The Chantelles" two LS40 speakers for their PA. Thanks to Lawrence for the pictures.
Serial number in the 1100s? - currently in the UK
An interesting specimen. Chassis no. 1786. The amp arrived in a large AC50 box with Sound City cloth. At some point in its history, extra capacitance was added along the lines of the final AC100s - the AC100/4 - paired 200uf capacitors in series; and the choke was presumably at that time also replaced (perhaps deliberately rather than out of necessity). The TCC capacitors in the preamp date to May and June 1965.
Early 1966 - a metal guard plate around the EL34s
Serial number 1168 (two sets of images, one previously posted as no. 1366) - currently in the USA
To date (23/12/2010), the lowest serial number to have the new valve plate guard. See the page on later Ac100 Mk2s for more on these amps. The first set of images can be seen on The Who Gear pages. Note the presence, still, of the two-line serial number plate. A nice tidy amp (after having been put back to spec.). The Woden choke has the code MW = December 1965. The plate reads 01168.
Serial number 1177 - currently in the USA
Complete with its original cab and trolley, the former now with a closed back, and the latter with non-original ball casters.