Contact us on 07970061897 or
  • Vintage 1970 Marshall JMP PA20 20w Valve Guitar Amplifier Stack
  • IMG_3091
  • IMG_3092
  • IMG_3093
  • IMG_3094
  • IMG_3095
  • IMG_3096
  • IMG_3097
  • IMG_3098
  • IMG_3099
  • IMG_3100
  • IMG_3101
  • IMG_3102
  • IMG_3103
  • IMG_3104
  • IMG_3105
  • IMG_3106
  • IMG_3107
  • IMG_3108
  • IMG_3109
  • IMG_3110
  • IMG_3111
  • IMG_3112
  • IMG_3113
  • IMG_3114
  • IMG_3115
  • IMG_3116
  • IMG_3117
  • IMG_3118
  • IMG_3119
  • IMG_3120

Vintage 1970 Marshall JMP PA20 20w Valve Guitar Amplifier Stack


In stock


We buy your vintage instruments for cash. Get in touch to find out more.

Vintage 1970 Marshall JMP PA20 20w Valve Guitar Amplifier Stack

Vintage 1970 Marshall JMP PA20 20w Valve Guitar Amplifier Stack

We are absolute suckers for these 20w Marshall amplifiers. The difficulty with the 50/100w amplifiers is that you need to really crank them in order to get the classic Marshall tone. The 20w counters this with that famous tone at lower volumes – hence their popularity. This particular amplifier comes with its original basketweave 2×10″ model 1917 cabinets, in beautiful condition. It really is a one of a kind setup. Includes all 4x original Brimar valves – 2x EL84s and 2x ECC83s – a very rare find! Unfortunately the transformer was changed in the past for a correct vintage replacement. We’ve had this checked over by our top amplifier tech who has given it the go-ahead.

In the left hand column, one of the original Celestion 7442 speakers has been professionally reconed as it was originally open circuit. It now sings and plays like a dream! Although this may not appeal to the collector, if you’re wanting a classic 60s Marshall amplifier, but don’t want to pay the top prices, this setup is literally perfect! We’ve played this lots since getting it back from our tech, and have fallen in love with the tone – it sings! Don’t be put off by the changes on this because it still gives out that monster sound.

Besides from all above, this setup is in wonderful condition. It really is one of the best conditioned setups we’ve had. The original tolex is in brilliant, shiny condition, with next to no scuffs at all!

Serial Numbers

Amplifier Serial Number: 6859A

Cabinet Serial Numbers: 33898 & 34094

The voltage selector is currently hardwired for 240v, so you guys across the pond may need a step transformer to play this correctly.

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.

Please have a close look at the high resolution photographs below, as these form part of our description.

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.