Marshall 9100-9200 User Manual

Valve Power

Amps

9100 & 9200

Denbigh Road, Bletchley, Milton Keynes, MK1 1DQ, England

Web Site - http://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.

Marshall Amplification plc

Tel: [phone]

Fax: [phone]

Jan ‘99

Handbook

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WARNING!

PLEASE READ THE FOLLOWING LIST CAREFULLY

A. ALWAYS fit a good quality mains plug conforming to the latest B.S.I. standards (UK only).
B. ALWAYS wire the plug in accordance with the colour code attached to the mains lead (UK only).
C. DO NOT attempt to remove the amplifier chassis. There are no user serviceable parts inside.
D. ALWAYS have this equipment serviced or repaired by competent, qualified personnel.
E. NEVER under any circumstances, operate the amplifier without an earth.
F. NEVER use any amplifier in damp or wet conditions.
G. ALWAYS ensure that the impedance of the speaker or speakers connected does not fall below the

amplifiers minimum impedance rating and is matched to this amplifiers output
I. PLEASE READ this instruction manual carefully before switching on.

Introduction

Models 9100 2 x 50 watt and 9200 2 x 100 watt stereo valve power amplifiers are the latest step forward in

valve rack technology from Marshall.

Built as dedicated guitar system based units, they incorporate many features that are both revolutionary
and evolutionary. From stunning styling through to the radical circuit design, these power amps are in a sonic
class of their own without any compromises to their true Marshall heritage.

The specially designed Marshall "Gold" front panel provides a deep recess in which the controls are sited
giving a smooth uncluttered finish whilst allowing the controls to be set and forgotten about, with little fear of
accidental re-adjustment. The removable top half contains a window, which in addition to showing the true
glory of the valves when the amp is in use, provides easy access to the output valves when replacement
becomes necessary.

The two power amp halves of your 9100/9200 are totally separate “MonoBlocs”, a feature that is normally
only found on expensive valve hi-fi power amps. This means that the only common electrical item (apart
from when specifically cross linking inputs) is the mains supply and that nothing that occurs to one power
amp can sonically react with the other half. Also in the unlikely event of one side breaking down, the other
side will carry on working regardless.

Our constant research into valve amplifier technology has resulted in further circuit design improvements
which dramatically effect the overall feel and playing response of the 9100 & 9200.

These improvements include Marshalls latest True Differential Inverter technology, which expands the
capability of the phase splitter (inverter) to be nearer to a true differential amplifier than most other circuits
used today. Put simply, the phase splitter takes the incoming signal and inverts half of it. This inverted half of
the signal forms the bottom half of the sound envelope and the non-inverted half forms the top half. The
effect of T.D.I. technology is to give a more defined spectrum of sound over a broader band width without
compromising the overdrive and compression effects for which valve amplifiers are famed.

This also allows more radical uses of feedback networks and the incorporation of the “voicing” switching
found on each channel. These incredible “voicing” options, which can be remotely activated, can be used to
greatly expand your pre-amps tone forming at the flick of a switch.

Mounting the 9100 and 9200 in a rack

Your 9100/9200 is a 19 inch 3U high rack mounting unit and subsequently we strongly recommend that, to
protect your investment, it is securely mounted in a suitable rack enclosure. A series of mounting holes are
provided both front and rear to allow sufficient fixings to be utilised. As with all rack mount products of
substantial weight, the rear of the unit must be supported as well as the front, therefore suitable brackets
should be obtained and fitted between the provided rear mountings and the rack case.

Ventilation and air flow

Even though the amplifier has fan reinforced cooling, it must be remembered that a valve amplifier, by
necessity, generates a high level of heat, and therefore should not be mounted or used in a situation without
adequate airflow.

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