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Vintage 1966 Vox UL4120 JMI Bass Guitar Amplifier Head


In stock


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Vintage 1966 Vox UL4120 JMI Bass Guitar Amplifier Head

Vintage 1966 Vox UL4120 JMI Bass Guitar Amplifier Head

With only 4 or 5 said to be left in existence, this legendary KT88-equipped UL4120 is not only the ultimate tone monster with its 120-watts of British power… it’s without doubt one of the rarest amps in the world!

The 4 & 7-series amplifiers were used extensively by the Beatles during the recording sessions for the Revolver album and beyond. The Rolling Stones, Led Zeppelin and Pink Floyd were also users of this short-lived amp line.

This particular amplifier is well documented online, having previously had bumble-bee and ‘200’ stickers added to the front panel. We have carefully removed both of these, leaving no traces. We have kept photographs of the before and after for anyone interested. 

Serial: 0248

Valve Brands: GEC

Transformers: Original

Voltage Selector: 115v, 160v, 205v, 225v, 245v Selector

This amplifier has been serviced to a playable & safe standard, by one of our leading amp techs. To find out more about what our service includes, please check out our terms and conditions before purchasing.


Overall very good condition, with only minor wear and tear to the tolex & scratches to the face. Please have a close look at the high resolution photographs below, as these form part of our description.


Internally and externally original, including transformers, except for minor service component changes i.e. caps, resistors, etc.

Comes with a custom made, brand new flightcase included in the price!

At The Music Locker we will do all we can for you to get the instrument you want. You’re more than welcome to come and have a play on this, coupled with one of our vintage guitars!

Additional Information

Country of Manufacture






In Stock



For more information on shipping prices, please visit our shipping page.

The Music Locker prides itself on offering vintage and collectable pre-owned instruments and equipment (the Products).

We take all reasonable steps to ensure the equipment has been inspected by a competent person in the UK to ensure it complies with UK safety standards. This may mean it does not comply with the current standards in the country in which it will be subsequently used. It is the purchasers’ responsibility to ensure it is inspected by a competent person knowledgeable with the relevant electrical safety standards within that country, prior to connecting to any live electrical circuit.

It is the philosophy of The Music Locker to keep all items as original as possible, only changing original components when absolutely necessary. This includes valves, capacitors, transformers, potentiometers, frets, etc. This gives the buyer the option of tailoring to their exact needs, and may mean that the item is not operating at optimum performance levels. Therefore, your personal preference may differ, depending on your circumstances (i.e. collector or musician), and you may decide to service the item in more depth upon receiving.

The Music Locker cannot accept responsibility for any costs of refurbishment to a standard different to the one advertised.