Marshall ST20H Studio JTM 20w Head

Weight: 20.4 lbs

The Marshall ST20H Studio JTM Head is a UK-built, all-valve amplifier inspired by the original JTM45, delivering a wide range of tones from smooth cleans to classic crunch. Its dual-channel, bridgeable design allows players to blend the Normal and High Treble voices for a more tailored sound, offering flexibility that goes beyond traditional single-voice amps.

With a built-in power reduction from 20 watts down to 5 watts, the ST20H maintains its tonal character at lower volumes, making it practical for studio, rehearsal, and smaller stage environments. Combined with modern features like a switchable FX loop and DI output, it balances vintage-inspired tone with real-world usability.

Highlights

• UK-built all-valve head inspired by the original JTM45
• 20W to 5W power reduction for flexible volume control
• Dual, bridgeable channels for blending tonal voices
• Classic Marshall EQ with Presence control
• FX loop and DI output for modern functionality

Specifications

Body

• Type: Amplifier Head
• Dimensions: 19.7" W x 9.4" H x 9.1" D

Hardware

• Construction: Valve (All-Tube)
• Channels: 2 (Bridgeable)
• Controls: Normal/Loudness II, High Treble/Loudness I, Treble, Middle, Bass, Presence
• Inputs: 4 x 1/4" (High/Low Sensitivity)
• Speaker Outputs: 5 x 1/4" (16Ω / 8Ω / 4Ω)
• Effects Loop: Yes (Series, Switchable)

Electronics

• Wattage: 20W (switchable to 5W)
• Preamp Tubes: 2 x ECC83, 1 x ECC83 (phase splitter)
• Power Tubes: 2 x 5881
• DI Output: Yes (1/4")

Miscellaneous

• Country of Origin: Designed and engineered in UK, Made in UK
• Included Accessories: Detachable power cable, speaker cable
• Other: Studio Series JTM platform with classic and blendable voicing

Why Buy from Tone Shop Guitars?

At Tone Shop Guitars, we pride ourselves on offering a curated selection of instruments backed by knowledgeable staff and exceptional customer service. Whether you're shopping online or visiting us in person, our goal is to help you find the right guitar and deliver a top-tier experience every step of the way.