The earliest Jennings Musical Industries Wah-Wah pedals: 1967

Vox retail pricelist, April 1967

"Beat Instrumental", vol. 48, April 1967, p. 24, the new effect connected explicity with the mid-range-boost of the new Vox solid state amplifiers. For further notices of Vox equipment in "Beat Instrumental", .

Beat Instrumental number 49. May 1967

Entry for the Vox Wah-Wah pedal in the Solid State brochure of Summer 1967.

A brief account of the development of the Wah Wah pedal in the States - well covered in other sources - will be given here shortly - simply to give some background to the pedals issued by Jennings in 1967. In the meantime, see for instance, .

The advert above, from "Beat Instrumental Magazine", April 1967, is one of the earliest public indications of JMI's move to produce a pedal of its own. The retail pricelist will not have been widely circulated.

The first Jennings wah-wahs are often called "greys" - the colour of their casings. Serial numbers apparently began at 5000 and run on certainly to 6451 and doubtless beyond. Whether there was one pedal for every number in the sequence remains to be seen. But they were evidently produced in reasonable numbers. The rather bonkers claim that there were "only 100 hundred made" probably stems from dealers or "gurus" bigging things up. These pedals are not protoypes, nor are they from 1966 as is sometimes said.

By the time we come to serial numbers in the 7800s, we have a model of a different sort. The pedal externally looks like an American model, but the plate on the bottom has the symbol of the Queen's Award for Industry, the name of "Jennings Musical Industries", and lower down "Made in Italy for VOX". Serial numbers are printed on a paper sticker.

At first, the 4uf capacitor employed in the circuit was a yellow Lemco - also used extensively in the preamps of the new Vox solid state amplifiers. Visible date codes on the caps in the pedals are "YB" = February 1967, and "YF" = June 1967. Thereafter, or apparently thereafter, one finds green TCC (Telegraph Condenser Company) 4uf caps. Date codes are "YE" = May 1967, and "YF" = June '67.

Transistors are generally 2N3707. The date code on the majority is "716" which indicates the 16th week of 1967 = April 1967. We also have "743" = the 43rd week of the year = October 1967. The assembly of pedals with these last may have taken place early in 1968.

Component date codes are simply termini post quem - "dates after which". Weeks or months could elapse between the manufacture of the component and its being picked off the stockroom shelf at the Vox Works in Erith for incorporation in a unit.

Serial numbers are hand-stamped on the paper label on the underside of the pedal. At some point - perhaps from early on - they were also stamped on the inside face of the base plate. See no. 6012 below.

Below, a growing register. If anyone knows of others that have not yet been included, do let me know.

For the time being, the pedals have been sorted into two groups: those with 4uf Lemco caps, and those with TCC. A straight serial number sequence may be be best in due course.

Serial number 5351

Serial number 5527

Advertised currently. Further pictures. The component board has been glooped in rubber (?). Another pedal, number unknown, at the foot of this section, is similarly glooped.

Serial number 5716

Serial number 5876

The 2N3707 transistor at board end has the date code "716" = April 1967.

Serial number 5879

The yellow Lemco 4uf capacitor has the date code "YF" = June 1967. The transistor at board end has been replaced.

Serial number 5964

2N3707 date codes are "716" = April 1967. The code on the Lemco capacitor is either "YE" or "YF" = May or June 1967. Two sets of pictures. The first three from the sale on ebay c. 2011, the others from .

Serial number 6258

The yellow Lemco capacitor has the date code "YB" = February 1967. Pictures .

Serial number unknown

Not quite possible to see the date code of the Lemco capacitor. The transistor at end of board has the code "TI 743" or "745" - either 43rd or 45th week (October) of 1967. Some rewiring evident (and new jack sockets).

Serial number unknown

Serial number unknown

The component board glooped up with black rubber solution (?)

Green TCC 4uf capacitor

Serial number 5932

Serial number 6012

The transistor at board end has the date code "710" = 10th week (March) of 1967.

Serial number 6388

Serial number 6451

Note the date code on the green TCC capacitor: "YF" = June 1967.

Serial number unknown

Green TCC 4uf capacitor.

Serial number unknown

Green TCC 4uf capacitor. The 2N3707 transistor immediately above has the code TI 743 = which probably indicates the 43rd week (October) of 1967.


Serial number 7857

The component board is "potted" with grey resin to prevent discovery of the circuit.

Serial number unknown

Clearly different from the one above. But only this photo for the time being.