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Marshall ST20C Studio JTM 20W Valve Amp Combo

Classic '60s Marshall tone from a compact, convenient package! Made in the UK, featuring 12" Celestion Creamback speaker, 20W/5W power switching, FX loop & DI output.



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Product Description

The amp that started it all is back! Delivering the same iconic JTM sound, the ST20C Studio JTM combo gives you all of that marvellous Marshall mojo but in a new compact size with some modern enhancements up its sleeve. Offering authentic, smooth, and valve-driven break-up at lower volumes — the Marshall ST20C is perfect for home or studio use, yet its superb all-valve design and 12" Celestion Creamback speaker packs a serious punch for live use too!

Classic Marshall Crunch, Contemporary Refinements

Like the original 30W head, the Marshall Studio JTM is loaded with two ECC83 preamp valves, two 5881 power amp valves and one ECC83 phase splitter — taking you right back to the renaissance of rock 'n' roll. The Studio JTM also offers the same control and versatility as older models, where simply patching the two channels together opens up a world of tonal possibility.

Handy power switching has been added to allow you to change effortlessly between 20W and 5W modes, with two loudness controls meaning that you can play as loud as you like! Marshall have really gone the extra mile for modern musicians by integrating features such as a DI output and FX loop too, bringing the JTM into the now!

Made in the UK

Handbuilt at Marshall's world-class factory in Bletchley, England, the ST20C Studio JTM features finger-jointed cabinets, hand-welded chassis, hand-soldered potentiometers and valve bases, and the highest quality componentry. Adorned with period-correct aesthetics from the same metal, red enamel poured "coffin" logo, to its fawn fret complete with gold piping and beading — the Studio JTM beautifully nods to the swinging '60s.

"When I was demonstrated the Studio JTM, it took me back to my original JTM45, it was my sound… I feel like it is going to be something special." — Terry Marshall (son of Jim Marshall, the founder of Marshall and creator of the original JTM45).

Key Features

  • Reproduces the legendary, warm tone of the original Marshall JTM that inspired generations of musicians — pioneered by the likes of Jimi Hendrix, Angus Young and Gary Moore.
  • Compact design that packs a punch, taking up less space than the original without sacrificing tone.
  • Easily swap between 20W and 5W power modes, for era-defining sound optimised for the stage, studio or the home.
  • Equipped with a 12" Celestion Creamback speaker, offering that definitive vintage tone.
  • Jump channels with a patch cable just like the original JTMs, to achieve a unique blend of heavier or treble-boosted sounds.
  • Updated with an FX loop, to allow for seamless use with your favourite reverb, delay or modulation pedals.
  • A new DI output feature lets you easily use the Studio JTM direct with a recording device or PA system — no mic'ing required!
  • Expertly crafted in Bletchley, England, with iconic touches that hark back to the 1960s.

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  • Power: 20W with Power Reduction to 5W
  • Valves: 2 x ECC83 (Preamp), 1 x ECC83 (Phase Splitter) and 2 x 5881 (Power Amp)
  • Channels: Single Channel with Four Separate Inputs (High Treble and Normal Loudness Controls)
  • Equalisation: Treble, Middle, Bass and Presence
  • Speaker Outputs: 5 x 1/4" Jack Sockets (16Ω Load / 8Ω Load / 4Ω Load)
  • Outputs: DI
  • Speaker Configuration: 1x12"
  • Speaker Model: Celestion G12M-65 Creamback (16Ω, 65W)
  • Weight: 17.8 kg
  • Width: 500 mm
  • Height: 460 mm
  • Depth: 265 mm
  • Matching Extension Cabinet: ST112
Elliot Stent author picture

Written by Elliot Stent

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Andertons Music Company's Registered Office: 58-59 Woodbridge Road, Guildford, GU1 4RF. Andertons Music Company acts as a credit broker and not a lender and only offers credit products from Secure Trust Bank PLC trading as V12 Retail Finance. Not all products offered by Secure Trust Bank PLC are regulated by the Financial Conduct Authority. Andertons Music Company is authorised and regulated by the Financial Conduct Authority, firm registration number 716155. Credit provided subject to age and status.