Marshall Studio JTM ST20C Combo

20W All-Valve Tube Combo — Vintage British Tone with Modern Flexibility

Inspired by the original Marshall JTM45 and built in the UK, the Studio JTM ST20C delivers classic era-defining valve tone in a compact, versatile format. With a switchable power output, premium Celestion speaker, rich control set, and authentic JTM voice, this combo brings the iconic Marshall sound to studios, stages, and homes alike. 

POWER & VOICING

• 20 W all-valve tube output with switchable reduction to 5 W — perfect for home, rehearsal, or mic’d performance environments.
• Single channel with two voice options — balancing classic clean and vintage crunch tones.
• Classic Marshall voicing inspired by the original JTM45. 

AMPLIFIER COMPONENTS

• Preamp valves: 3 × ECC83 (including phase splitter). 
• Power amp valves: 2 × 5881 for authentic tube warmth and headroom. 
• Handcrafted in Marshall’s UK factory — combining heritage design with modern reliability.

SPEAKER & TONE DELIVERY

• 1 × 12″ Celestion G12M-65 Creamback speaker — classic low end, warm midrange, and refined highs. 
• Enhanced power handling for rich dynamics and bold sonic presence. 

CONTROLS & FUNCTIONALITY

• Presence, Bass, Middle, Treble — full 3-band EQ and presence control for tonal shaping. 
• Loudness 1 / Loudness 2 controls for level-dependent tone response. 
• Switchable FX loop — integrates pedals after the preamp section. 
• DI output for recording or live PA connection. 
• Impedance selector for 4 Ω / 8 Ω / 16 Ω speaker configurations. 

CONNECTIONS

• Four ¼″ instrument inputs (two high-sensitivity, two low-sensitivity). 
• Multiple speaker output jacks accommodating various load configurations.
• FX loop Send/Return for effects integration. 
• Dedicated DI out for direct recording/PA feed. 

DIMENSIONS & BUILD

• Classic Marshall black covering with gold piping and vintage aesthetic flourishes. 
• Compact tube combo footprint — easy to transport for rehearsal and stage use. 
• Weight approx. 17.8 kg / 39.2 lbs (cabinet only). 
• Dimensions approx. W 500 × H 460 × D 265 mm (incl. handles/feet). 

IDEAL FOR

• Players seeking classic British valve tone in a portable format. 
• Studio and home players requiring flexible power and rich dynamics. 
• Musicians blending vintage inspiration with modern reliability.