Marshall Amplification JCM800 - User Manual

Marshall Amplification plc
Denbigh Road, Bletchley, Milton Keynes, MK1 1DQ, England
Tel : [01908] 375411 Fax : [01908] 376118
www.marshallamps.com
Whilst the information contained herein is correct at the time of publication, due to our policy of constant improvement
and development, Marshall Amplification plc reserve the right to alter specifications without prior notice.
BOOK-00067-00 / 2 / 02
Owners Manual
JCM800 2203

Marshall Amplification JCM800 Specifications

General

Model	JCM800
Preamp Tubes	3 x ECC83/12AX7
EQ	Bass, Middle, Treble
Type	Tube Amplifier
Power Output	50W or 100W
Channels	1 or 2
Power Tubes	2 x EL34 (50W) or 4 x EL34 (100W)
Inputs	2
Speaker Outputs	4, 8, or 16 Ohms
Effects Loop	Yes
Speaker Configuration	1 x 12"

Summary

From the Chairman

Important Safety Instructions

Introduction

Front Panel Features

Power Switch

Controls the mains power supply to the amplifier. Switch is illuminated when 'On'.

Standby Switch

Warms up valves and prolongs their life. Used for breaks and powering down.

Presence Control

Adds high frequencies for crispness and bite, affecting tone cutting power.

Bass Control

Adjusts the amount of low frequencies (bottom end) in the amplifier's tone.

Middle Control

Controls the mid-range frequencies, affecting guitar tone fatness and fullness.

Treble Control

Determines the amount of treble, making the guitar's tone brighter as it's turned up.

Master Volume

Controls the overall output volume of the amplifier, balancing preamp gain.

Pre-Amp Volume

Drives pre-amp valves for distortion and harmonically rich tone.

High Sensitivity Input

Input for low-output pickups, or high-output for harder preamp drive.

Low Sensitivity Input

Designed for hot (high-output) pickups; try both inputs for best results.

Rear Panel Features

Effects Loop Send & Return Jacks

Connect external effects pedals or rack processors for enhanced sound flexibility.

Effects Loop Level Switch

Switches between +4dBV (rack) and -10dBV (pedal) levels for effects loop.

Effects Loop Bypass

Bypasses the effects loop circuitry to maintain original tonal integrity.

Effects Loop Return Jack

Connects the mono output of an external effects processor.

Effects Loop Send Jack

Connects the mono input of an external effects processor.

Loudspeaker Output Jacks

Connect external speaker cabinets. Ensure correct impedance matching.

Output Selector

Matches amplifier output to speaker load impedance to prevent damage.

Mains Selector

Matches transformer voltage to incoming mains voltage for safe operation.

Mains Input

Connection point for the detachable mains (power) lead.

Mains Fuse

Specifies the correct value for the mains fuse, crucial for safety.

H.T. Fuse

Specifies the correct value for the High Tension fuse.