UPDATES
Older blog / update entries are now here.
February and March 2020
31st March
Vox MC50 (Metal Clad 50) serial number 3901, sloping front, solid state rectified, assembled by Triumph Electronics for Vox in early 1965. Serial numbers ran in the same sequence as those assigned to AC50 guitar and bass amplifiers. Judging by small ads placed in music papers of the later 60s and early 70s, Triumph made reasonably large quantities of these Public Address units. They are scarce today however. Thanks to Daniel for the pictures.
Note the all valve preamp and power amp. Triumph also produced hybrid Public Address amplifiers for Vox - transistor preamp and valve power amp - long before the company embarked on making the 7-series range.
23rd March
Some pictures to show how Mullard mustard capacitors will have arrived at Triumph Electronics in Croydon (the contractors who first assembled AC50 chassis for JMI) in the mid 1960s. The values used in AC50 mark 1s and early mark 2s were: 0.022uf, 0.22uf, 0.01uf and 0.1uf.
12th March
Currently on Reverb, "Vox Sound Equipment Limited" AC50 serial number 1078, from early 1969. Other VSEL AC50s are on this page.
9th March
Serial number 7481. In common with many amps with numbers in the 7000s, the mains cable is hard wired. The serial number plate is positioned where the mains socket should normally be:
An AC50 box sold a little while ago. The box belonged to an amp owned and hired out by "International Entertainer Services". IES was a fairly large player on the hire scene in the early and mid 1970s.
8th March (4)
Currently for sale in Germany - ebay kleinanzeigen - another early large box AC50 mark 2, serial number 1367 with what is probably a later Foundation Bass speaker cabinet - double pin corners, 18" Celestion greenback, grille cloth redone (?) in brown. Note the aluminium plate for the speaker connectors on the back panel - much as serial number 1354.
8th March (3)
Serial number 3905. The amplifier alone came up for auction on ebay in 2012. Pictures on this page. Since then its grille cloth has been renewed, and the amplifier paired with a Foundation Bass speaker cabinet from another source.
8th March (2)
Currently at GP Guitars, serial number 3256:
The solid back panel to the speaker cabinet is a later addition employing the original screws and Amphenol speaker socket (mounted off-axis in relation to its screws). The vinyl is similar to Thomas Organ vinyl.
8th March
At Mill River Music, serial number 4073:
Currently on Reverb, serial number 4764:
22nd February
Serial number 7027 - a Foundation Bass set - now registered on this page. Thanks to Marty.
13th February
Currently on Reverb, an AC50 mark 2 (twin channel, valve rectified, grey panel) in a small box, serial number unknown, output transformer replaced. JMI sent a number of new mark 2 chassis out in small boxes in the last third of 1964 - see the examples on this page.
Date codes on the mustard caps are "A4N" and "B4" = first and second quarters of 1964, none visible however on the blue Hunts caps
6th February
Some new pages on serial number 1354, the earliest large box AC50 that has surfaced to date: general; preamp; and power amp.