The ‘Univox’ Les Hills. United Kingdom, 1940

Univox 1940
Univox 1940

Developed by the Jennings Organ Company,West Hill, Dartford (later  Jennings Musical Industries; creators of the Vox range of organs and amplifiers) in the UK, the Univox was a monophonic, portable, piano attachment instrument similar to the Clavioline. It’s sound came from a vacuum-tube sawtooth generator (as opposed to the square wave of the Clavioline) which in turn was modulated by a diode waveform shaper circuit. The pitch range was extended to three octaves (five in later models) using a frequency division technique which also allowed the playing of multiple octaves of the same note from one key. The instrument was controlled by a three octave F to F miniature wooden keyboard and came with it’s own 6 watt amplifier and 8″ speaker all built into a leather carrying case;

“The Clavioline keyboard was on the UK market before the Univox..  Clavioline originated in France and was imported for the British market by the UK/French company “Selmer” (based in Charing Cross road, London). Their main product were woodwind & brass instrument sales. They were not really into electronic products though the Clavioline was a good product. It was also expensive.

Tom Jennings saw the market potential and already had a good slice of the keyboard sales for accordions etc. Tom found a local electronic engineer, Les. Hills, who studied the Clavioline and designed another circuit different to the existing French patent.  Unfortunately the product was not at all reliable, with most units breaking down almost as soon as they got to the end customer. Some of this problem was due to instability in the earlier circuit design but mostly due to choice of suitable components and mechanical shortcomings.

Les had only been employed for the circuit design. The mechanics having been cobbled together by the accordion service men at the time. I was head hunted by Tom to sort out the reliability problems. This took a few months of circuit, component testing plus improvements to the mechanics. This was in 1951 period.

In about 1951/1952 the Univox took off in a big way due to its competitive price and Tom’s country wide marketing program.  The first version was the J6, single keyboard model, later followed by the J10 with two rows of Tone & effect tabs. All models were supplied with metal screw-on clips, to fasten it under the right hand side of a piano. Later we designed an adjustable chromed stand that enabled the user to do gigs in other locations with out having to screw on fixing brackets each time.  Most customers in those days were either Pub owners or pianists playing Pub gigs.

So, No the Clavioline was not the same as the Univox, only catered for the same market.”

Derek Underdown. Technical Director/Chief Engineer at JMI/Vox from  1951-1967

Univox 1940
Univox 1940

The Univox keyboard had a unique a double contact system under the key allowed basic control over the note shape – striking the key harder caused a thyratron impulse generator make a shorter decay, creating a staccato effect, striking the key softly gave a long decay of up to two seconds. A vibrato oscillator was also provided to modulate the output and also to retrigger the thyratron tube to create ‘mandolin’ type repeated notes. The Univox’s front panel consisted of fifteen switches to further control the timbre of the instrument, three vibrato controls, a thryratron modulation control and an overall knee operated volume control.



10 thoughts on “The ‘Univox’ Les Hills. United Kingdom, 1940”

  1. I have an Univox model J6 part no 3435. It works, just about, with very little volume. I want to know if it is worth getting repaired and if so what would it be worth, if anything, today.

  2. Hi Ed , I’ve recently obtained a univox j6 and have been trying to work it out. All powers up but nothing coming out of speaker. Is there a volume control somewhere ? Also did you get yours repaired and if so I would appreciate a contact if possible. If anyone else is reading this I would appreciate any help.

    1. Steve, I have the J10 model which I periodically fire up and try to figure out what does what. Your volume issue might be that you are not using the volume lever that attaches to the underside of the keyboard.

    2. I know its a long time ago your post. the multi plug soldered connections have problems with the soldered joints which would cause no sound issues.
      Alan SLEEP
      I still have it from 1962.

    1. Dan, I have a Univox that belonged to my late father. It has a great deal of sentimental value to me as I have many memories of it from when I was a child, but realistically there is no reason for me to hang on to it. It means nothing to my kids so I’m looking for a collector or enthusiast who would be interested in it. I have searched the internet for a suitable way of advertising a sale but nothing stands out as being the right way to see that it goes to a good home.

      Can you offer any advice please?

      1. Hi Terry, I’m from Sacramento, CA & have strong interests in acquiring tube generated keyboards, & currently replacing tubes in a working S-4 Hammond 1954 Chord Organ. Depends on what state &/or country of origin you hail from tho. How much are you offering to sell the Univox J6 for? Please reply back to me here &/or at & hopefully we can work something out sir.

  3. I would highly recommend the bi-annual VEMIA on-line auction which is hosted in the UK and home to the sale of a very significant amount of cherished/rare vintage studio equipment. You would be sure to find a buyer on there for your Univox as it has a large audience of pro musicians and collectors.

    VEMIA Website:

    D.A.Wilson, Hideaway Studio.

Leave a Reply

Your email address will not be published. Required fields are marked *

%d bloggers like this: