Marshall Amplification manual Introduction, JTM45 O/S Front and Rear Panel Features

WARNING!

Please read the following list carefully.

A.ALWAYS use the correct power cord

B.NEVER attempt to by-pass the fuses or fit ones of the incorrect value.

C.NEVER attempt to replace fuses or valves with the amplifier connected to the mains.

D.DO NOT attempt to remove the amplifier chassis, there are no user serviceable parts.

E.ALWAYS have this equipment serviced or repaired by competent qualified personnel.

F.NEVER use an amplifier in damp or wet conditions.

G.DO NOT switch the amplifier on without the loudspeaker connected.

H.ENSURE that any extension cabinets used are of the correct impedance.

I.PLEASE read this instruction manual carefully before switching on.

WARNING : This apparatus must be earthed!

WARNING : Do not obstruct ventilation grille and always ensure free movement of air around the amplifier !

KEEP THESE INSTRUCTIONS

Introduction

As Jim has already stated, our goal, when building this limited edition, offset reissue, was simple. To make it as close to the original as humanly possible! To this end we have gone to great lengths to recreate every single aspect and specification of this visually and aurally striking item-from sourcing an exact replica of the original coffin logo (so called because it was first made for us by a coffin manufacturer!), to ensuring that the output and power transformers boast the same exact core lamination materials as they did back in 1962. Likewise, the amplifier circuit itself is hand- wired on a hand-built tagboard, the chassis is constructed from aluminium and the valve complement is 3 x ECC83s in the preamp, a GZ34 rectifier and a pair of KT66s in the power amp - just like the original.

We are delighted to report that many of our suppliers went to the same exacting lengths as we did when providing us with parts for this reissue, and none-more-so than Celestion. Thanks to their commitment to this project they successfully recreated the Alnico magnet, silver G12, model T0652 loudspeakers found in our museum piece-right the way down to matching the same exact colours and lettering fonts used on the original label!

As is the case with all our amplifiers, the best way for you to truly appreciate this remarkable reissue is to grab your favourite guitar, plug it in and play. Enjoy!

JTM45 O/S Front and Rear Panel Features

Front Panel Functions

The JTM45 O/S features four inputs, two per channel. The first channel is voiced for a high treble response with the second channel voiced for normal response. The first input of each channel has more gain than the second input of each channel and hence is louder. Though the first input of the first channel is the input that most guitarists use, don’t hesitate to experiment. Some guitar players prefer to mix

the two channels by putting a patch lead between the second input of channel 1 and the first input of channel 2 and then plug their guitar into the first input of channel 1. Doing this allows you to mix the different tonal characters of each channel for greater flexibility.

See Diagram right.