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WARNING!
PLEASE READ THE FOLLOWING LIST CAREFULLY A. ALWAYSfit a good quality mains plug conforming to the latest B.S.I. standards (UK only).
B. ALWAYSwire the plug in accordance with the colour code attached to the mains lead (UK only).
C. DO NOTattempt to remove the amplifier chassis. There are no user serviceable parts inside.
D. ALWAYShave this equipment serviced or repaired by competent, qualified personnel.
E. NEVERunder any circumstances, operate the amplifier without an earth.
F. NEVERuse any amplifier in damp or wet conditions.
G. ALWAYSensure 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 READthis 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 ÒMonoBlocsÓ, 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 ÒvoicingÓ switching
found on each channel. These incredible ÒvoicingÓ 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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9100 and 9200 valve power
amplifiers
1. Channel A mains power rocker switch Connects channel A to incoming mains supply.
LED 3 indicates red when activated.
2. Channel A standby switch Connects channel A's high voltage circuit to the
power supply. LED 4 indicates green when
activated.
Note! Items 1 & 2 are marked 0 &1 (to comply
with international regulations), 0 is off and 1 is on.
Note! To conserve valve life, standby switch 2
should remain off for at least 1 minute after
powering up the amplifier.
3/4. Mains & standby LED's.
5. Voice B LED -
Indicates red when channel A's voicing option B is
activated.
6. Channel A voice toggle switch Selects voice option A or B, this function is
repeated on a remote switching jack on the rear
panel (see rear panel functions). The switch should
be in the B position for the remote switch to be
operative.
7. Channel A presence control Rotary control to boost the upper mid to highfrequency content of sound.
8. Channel A gain control Rotary control to set and balance the incoming
signal level.
9. Channel B gain control
10. Channel B presence control
11. Channel B voice switch
12. Channel B voice LED
13. Channel B standby LED
14. Channel B mains LED
15. Channel B standby switch
16. Channel B mains switch
Note! Channel A's notes also apply.
17. Upper front panel fixing screws Use 2mm (5/64) allen head driver to remove.
18. Front rack mount fixing holes.
Rear Panel
1. Mains input socket Connects amplifier to incoming mains supply.
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A
B 9200Dual MonoBloc Amplifier
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