User manual MARSHALL JCM 900 VALVE 4100 DUAL REVERB

[. . . ] For over three decades my company has been dedicated to the design and manufacture of the finest amplification systems in the world. By `listening' to guitarists from all over the world we know that their needs are constantly changing, demanding more from their amplification. The only way to cope with these new demands is to invest into the research & development of new models capable of fulfilling their ever more extreme requirements. This investment has led to remarkable innovation within our product ranges over the years. [. . . ] Service should be obtained as soon as possible to prevent the premature ageing of (OPV2-OPV3). Note: Some effects such as distortion and compression are best suited to connection via the front panel input as opposed to the loop. VALVE OUTPUT POWER The JCM 900 range use high quality 5881 output valves (x2 in 50 Watt models, x4 in 100 Watt models) for their unique distortion properties and fluid tone. With most valve amplifiers, particularly Marshalls', the best sounds are achieved when the Master Volumes are set high enough to be utilising the driving power of the output valves to the full. This delicate working balance between the pre-amp and power amp levels can only be achieved by experimentation. You will find that all the JCM 900 models like to work hard and are designed to withstand prolonged use at full power quite readily. The PB100 Power attenuator is ideal for this use (connects between amp and cabinets) as it will allow you to run your amp at full power but keep the overall volume low. The important thing to remember here is that it is the interaction between all the controls that plays a part in achieving your sound. 2. Effects Send Socket Jack socket for connection to the input of external effects processor. 11 & 12. Valve Failure LED (OPV2-OPV3) Valve Fuse (OPV2-OPV3) Similar functions to items (9) and (10) but operating on OPV2 and OPV3. 3. Effects Return Socket Jack socket for the connection from the output of external effects processor. 13. Mains Power Input Connects the amplifier to the mains power supply. 4. Recording Compensated Line-Out Socket Jack socket for direct connection to recording equipment or PA system. The signal is specially filtered for optimum recording performance. Note: Always ensure that the incoming mains voltage matches that of the amplifier. Direct Line-Out Socket Unfiltered pre-amp signal for connection to external power amplifiers. 14. Mains Power Fuse Protects the amplifier and mains supply in the event of a fault. FRONT PANEL FUNCTIONS 1. Master Volume Channel B Controls the overall volume level of Channel `B'. Combo versions feature 4 or 8 Ohm options. Note: Always ensure that the fuse value matches the labelling on the amplifier rear panel. Channel B `ON' Push Switch/LED Indicates red when Channel `B' is selected either manually or by remote footswitch (models P802). 2. Channel `A' Pre-Amp Gain Control Sets the gain level for channel "A". Lower settings give clean sounds - higher settings for medium drive and crunch rhythm. 7. Loudspeaker Output Jack Sockets Parallel wired jacks for linking speaker cabinets. Ensure that the speaker system is easily capable of handling the full amplifier power and that the impedance (item 6) is correctly selected. Footswitch Jack Socket Connects the remote dual footswitch (models P802) for reverb ON/OFF and Channel A/B switching. 3. [. . . ] A) 6 82 4 6 10 0 10 82 0 10 4 6 82 0 10 4 6 82 0 10 BASS 4 6 82 0 10 4 6 82 0 10 4 6 84 PREAMP (CH. A) 4 6 8 INPUT 0 GAIN Model 4100 1 POWER STANDBY 100W Hi Gain Dual Reverb JCM 900 4 6 82 4 2 FOOT SWITCH 0 10 0 10 VOLUME REVERB VOLUME REVERB PRESENCE MIDDLE TREBLE LEAD GAIN 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 REAR PANEL EFFECTS LINE OUTPUT POWER LEVEL OUTPUT LOUDSPEAKERS 100W R. M. S. Made in England by WARNING!: OUTPUT VALVE FUSE MODE FAIL T500mA T500mA FAIL MAINS INPUT 120V ~ 60Hz 375 Watts FUSE 220/240V - T2A 110/120V - T4A ! SHOCK HAZARD. TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. THIS APPARATUS MUST BE EARTHED. IMPEDANCE SELECT TION RISQUE DE CHOC ELECTRIQUE. [. . . ]