List of updates / new info. on Vox solid state amps (1967-1972)
Conqueror serial number 1340 currently in Iceland (owned by Arni Heiðar). Thanks to Ingi for the pictures.
Currently on sale in Germany, Super Foundation Bass serial number 2124, "Vox Sound Equipment Limited", probably made towards the end of the first third of 1969. The standby circuit is still present. The speaker cabinet is of the earliest type - single 18" and port at bottom. Both amp and cab have their original covers (a rare thing) and the amp its footswitch.
A series of updates on the way. For the time being, Defiant serial number 1226. A good number of Defiants with numbers in the 1200s were exported to Europe.
Foundation Bass amplifiers: - still no definitive pictures of a serial number below 1141. But trawling through some old images, it turns out that the one immediately below (from ebay, October 2006) is actually serial number 1150, sold recently.
The original (?) shop sticker was evidently removed at some point before the recent sale (third time on ebay.uk), but clearly the same amp (loose threads on grille cloth, rust on vents).
4th August (2)
General pictures of Vox Traveller serial number 1177 are now here. Details are here. The date codes of a number of transistors are "8C" = March 1968. The amp must have been produced therefore around April '68, ie. well into the period during which Jennings Musical Industries was in the hands of the receiver. JMI came to an end in June/July.
Following on from yesterday's entry, a few details from Chris on the transformers that Twickenham and Lemark produced for Vox solid state amplifiers.
The driver transformer, as has been said, is part no. TT3944.
Mains transformers: 30W (Conqueror and Dynamic Bass) = part no. TT3945; 50W (Defiant and Foundation Bass) = TT3946; 100W (Supreme and Super Foundation Bass) = TT3947.
Reverb driver transformers were TT4070:
The reverb driver transformer of a Vox PAR100SS
The mains and output transformers used in the various versions of the PA50SS, PA100SS and Midas amplifiers were NOT made by Twickenham or Lemark, however. Part numbers are ZD231 and ZD232.
Open frame mains transformer in a Vox PAR100SS - part no. ZD231, maker at present unknown.
Some more about George Stow and Stow Electronics, the fore-runner of the "Birch-Stolec" Group, which effectively ran "Vox Sound Limited" from mid 1971 to end of days in early 1973. See the entry for 14th July, below. Notes gathered here and in coming entries will be used to update other pages.
A huge thanks to Chris Burtenshaw, who worked at Twickenham Transformers, then Lemark Electronics, from 1968-1984, for key info - more to follow.
Stow Electronics was effectively the centrepiece of the Stow Group, which was known as "Stolec" from at least 1968. The other satellite companies were Startronic Ltd, Technical Encapsulations Ltd, and Digitizer Techniques.
(ref. "Electronic Components" magazine, no. 8, 1967; "London Gazette", 18th Nov. 1969; "Instrument Practice" magazine, no. 22, 1968).
The main business of the Stow Group was the manufacture of electronic switches.
"Twickenham Transformers" had come to be part of the Group by 1968, though the company was not at that time owned by Stow. Twickenham was based in Haywards Heath, Sussex.
(ref. "Electrical Times", no. 154, 1968; "Instrument Practice" magazine, no. 22, 1968).
Twickenham Transformers became Lemark Electronics in the summer of 1970.
(Information from Chris Burtenshaw, who worked at Twickenham and Lemark from 1968 to 1984. More on Lemark to follow.)
The main Stow Group (Stolec) factory, new in 1967, was on the Ponswood Industrial Estate, Windmill Road, Hastings/St Leonard's on Sea, Sussex.
(ref. "Electrical Times" magazine, no.152, 1967).
It was this factory, under the wing of the "Birch-Stolec" Group from mid 1970, that took on the manufacturing of Vox equipment in mid 1971.
A driver transformer from a "Vox Sound Limited" PA amplifier. These were also used in the guitar and bass amplifiers. As the sticker notes, the transformer was manufactured by Lemark Electronics, part number TT (Twickenham Transformers) 3944. The part codes of other transformers - all with TT numbers - will be listed soon.
Some pictures of Vox Traveller serial number 1177, complete with its original cover, on their way. For the time being, the serial number plate and a detail of the main filter capacitor showing date code "A8" = January 1968. The amp is therefore likely to have been made February/March 1968.
Date code "A8" = January 1968.
The highest serial number for a JMI Traveller to date is 1297, so perhaps around 60-100 were produced in the first third of 1968. One has to allow for the fact that amps produced in late 1967 might have remained in the Vox Works for some time before being given serial number plates prior to despatch.
At least one Traveller - serial number 2001, presented to the son of a Vox contractor - was issued though perhaps not made by "Vox Sound Equipment Limited".
VSEL began its sequence of numbering at 2000 (known from a surviving Dynamic Bass amplifier).
Sold on Gumtree (UK), 2015.
Defiant serial number 1204. Preamp chassis no. 1315; power amp chassis no. 1776. Signal path capacitors are still the yellow Lemcos. The power amp chassis has red CCL caps dating from 1966 and early 1967.
The latest component date codes visible are February 1967.
14th July (2)
Below, thanks also to Lee, a set of stickers for Vox Guitars at the World Expo of 1967. From late 1966, JMI played little or no part in promotions in the States.
Thomas Organ part number 88-5417-1.
Some more on George Stow. Stow, as has been noted on other pages, was important both to "Vox Sound Equipment Limited" and to "Vox Sound Limited". For the former, as owner of "Stow Electronics" and "Twickenham Transformers", he oversaw the supply of various components for the solid state range.
"Twickenham Transformers" was the parent company from which "Lemark Transformers" later sprang.
Lemark driver transformer.
Some early VSEL transformers are still labelled "Twickenham", however, as in the case of Defiant serial number 2032 - pictured below.
Defiant serial number 2032 - power transformer labelled "Twickenham Transformers Ltd.". "Twickenham" were based in Haywards Heath, as was "Lemark" initially. "Lemark" moved to the Ponswood Road Industrial Estate in St Leonard's on Sea, however, some time after VSL production was transferred there in late 1971 (to the Birch Stolec factory). The West Street Works in Erith were given up.
A little way into 1969, one finds the same transformers branded as "Lemark". But the part numbers - prefixed with "TT" (either printed or written) - indicate the lineage.
When VSEL began to crumble in late 1969 / early 1970, George Stow put the better part of his existing electronics businesses into liquidation and formed the "Birch-Stolec" group. Vox was saved and recast as "Vox Sound Limited" with support from "Corinthian Securities" (sometimes and inaccurately called the "Corinthian Bank"), a company with a none-too-stellar reputation in the City. But Vox survived.
George Stow became its managing director:
"Melody Maker" magazine, 14th August 1971.
With the collapse of VSL in early 1973, the story in a sense becomes even more about people. What happened to the employees? Where did they find new work? Reg Clarke, General Sales Manager of JMI and VSEL, had already moved to Dallas Arbiter (in 1970). George Stow, it turns out, joined Reslosound after VSL came to end. Below, a detail from a piece on the Frankfurt Musikmesse of 1975 published in "International Musician", April 1975.
"International Musician", April 1975. I had put the piece from which this detail comes on the updates page of Vox AC100 website a little while ago without really registering the presence of Stow.
Vox in its three incarnations - JMI, VSEL and VSL - had offered Reslo mics in its catalogues for many years. And three of its own mics - the Vox VL1, VL2 and VL3 - were in fact varieties of standard Reslo productions. George Stow will have known the Reslo people long before he joined.
Rick Huxley, mentioned in the "Melody Maker" snippet above as a sales rep., had been the bassist for the Dave Clark Five. Following the collapse of VSL in '73, he opened a music equipment store near the Oval with Doug Jackson, a friend.
A Vox matchbook featuring Dusty Springfield, very scarce these days. Thanks to Lee for the image.
A note on the two printings of the first JMI solid state brochure, one issued around May/June 1967, the other later in the year. A third was produced in the second half of 1968 by "Vox Sound Equipment Limited".
There are several ways to distinguish the various printings:
(1) The first issue has a plain cover. Later ones have a picture in black and blue.
Front cover of the first printing.
(2) Copies of the second issue often have turquoise rather than blue illustrations and legends:
First printing above, second printing below.
First printing above, second printing below.
(3) Perhaps most telling if the catalogue has lost its front cover (as the second of the two above has), is the caption to the Gyrotones. The first issue has "Now with the 'Whirly-Bird' Sound". The second has "Now with 'Wrap-Around' Sound":
First printing above, second printing below.
(4) The third printing has "Vox Sound Equipment Limited" rather than "Jennings Musical Industries" on its back cover.
Also thanks to Pete Kappa, a circuit diagram (schematic) of the JMI Dynamic, Foundation and Super Foundation Bass preamp, drawn from Foundation Bass serial number 1443: