1985 Marshall JCM800 Model 4010 — 50-Watt Combo with Original Celestion G12M-70

Original vintage Marshall character, classic British crunch, and a history of expert care.

I’m selling my all-original 1985 Marshall JCM800 Model 4010 50-watt combo, equipped with its original Celestion G12M-70 12-inch speaker. This amp has been used mainly in the studio and maintained by legendary amp tech Roy Blankenship and Steamboat Amps.

The 4010 brings the celebrated 50-watt JCM800 2204-style circuit into a self-contained 1×12 combo—classic Marshall tone without a separate head and cabinet. Its straightforward, single-channel design delivers the raw attack, assertive midrange, and dynamic crunch that make this era of Marshall so appealing.

Features & Benefits:

• 50 watts of all-tube Marshall power — plenty of authority for band use, with the punch and presence that make the JCM800 a compelling studio or stage amp.

• Classic single-channel, master-volume design — separate preamp and master-volume controls let you balance preamp drive against overall output, from gritty rhythm sounds to aggressive rock saturation.

• Original Celestion G12M-70 12-inch speaker — retains this amp’s original speaker configuration and period character; the G12M-70 is also documented in another 1985 Model 4010 example.

• High- and low-sensitivity inputs — two input options provide flexibility for different guitar outputs and approaches to gain.

• Presence, bass, middle, and treble controls — straightforward tone shaping to dial in bite, body, and the midrange needed to stand out in a mix.

• Convenient 1×12 combo format — the appeal of the 50-watt JCM800 circuit in one package, rather than a separate head-and-cabinet setup.

• Mainly studio-used and professionally maintained — cared for by Roy Blankenship and Steamboat Amps, with a maintenance history that sets this particular amp apart.

A Real Vintage Marshall for Players and Collectors

For a guitarist looking for unmistakable JCM800 crunch—or a collector seeking an all-original example—this 1985 Model 4010 offers the appeal of a genuine vintage Marshall in a practical combo format. It’s a direct, no-frills amplifier built around the sound: punchy rhythms, cutting leads, and expressive response to your playing.

A classic Marshall with its original Celestion speaker, mainly studio use, and a history of expert maintenance.