Marshall Studio JTM ST20C 20W 1X12" Combo Guitar Amplifier


The first JTM amp created a legendary sound that inspired generations of musicians. In honour of that, the ST20C brings the iconic 60’s tone that initially launched Marshall to the present day, in a more compact format.

Whether you’re at home, in the studio, or on the big stage – the ST20C can adapt to bring exceptional tone to any situation with built-in power reduction technology, enabling players to switch between 20W and 5W.


  • Model: ST20C
  • Range: Studio
  • Technology: Valve
  • Channels: 1 with 2 voicings

  • Output wattage: 20W (with power reduction option to 5W)
  • Outputs: DI output and 5 x 1/4” speaker outputs (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

  • Speaker configuration: 1x12”
  • Power handling: 65W
  • Speaker model: Celestion G12M-65 Creamback (16Ω, 65W)
  • Unit impedance: 16Ω

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

  • Cable: Detachable power cable included