Marshall ST20H Studio JTM 20W Guitar Amplifier Head


The unrivalled number one is here, just smaller. Reproducing the legendary, warm and smooth tones of the original Marshall JTM, the Studio JTM packs a punch. Swap between 20W and 5W at the flick of a switch and let the era-defining sound of the JTM steal the show, whether it’s playing at home, or on stage. Make sure to pair the ST20H with one of our Studio cabinets for a small but perfectly formed Marshall rig.


  • Model: ST20H
  • Range: Studio
  • Technology: Valve
  • Channels: 1 with 2 voicings

  • Output wattage: 20W (with power reduction option to 5W)
  • Outputs: 5 x 1/4” jack sockets (16Ω load / 8Ω load / 4Ω load)
  • Inputs: 4 x 1/4" jack instrument inputs (high/low sensitivity)
  • Controls: Treble, Middle, Bass and Presence
  • Effects: None
  • Effects loop: Yes, send/return

  • Preamp valves: 2 x ECC83, 1 x ECC83 (phase splitter)
  • Power amp valves: 2 x 5881

  • Cable: Detachable power cable included
  • Cable: Speaker cable included