Master Volume Models
These models have been developed from the highly successful Marshall 2104 M.V. Combo, to provide two guitar valve Combo's of similar circuitry and facilities, but with differing speaker configurations, compactness and portability.
Apart from the sleek new J.C.M. 800 styling, which places the controls on the full width fascia panel, offering much improved use and vision, there have been other important developments. By using newly developed loudspeakers, these Combo's have been given a new depth of sound, without losing the smooth overload characteristics of the previous model. Also, treble and presence controls have been redesigned to give greater swing and less interaction with the rest of the tone network. The Combo's feature the original Marshall Master Volume circuitry, to enable the musician to reproduce the classic valve overdrive sound at any volume level. By varying the preamp volume and master volume controls, the output can be varied from a clean crisp sound to a rich overdrive sound. Exactly as model 2104 featured two inputs of different gain, so too with the new 4010 and 4104, both these channels mix into the newly modified tone circuitry of treble, middle and bass. Model 4010 features a single 65 watt high sensitivity speaker; and model 4104, though only slightly larger; has two of the same units to give greater projection of sound where required.
Split Channel Model
This brand new Combo, like the new 2000 range of amplifier heads, is the result of Marshall's years of experience in the field of sound engineering and must represent a high point in modem guitar amplification technology.
The preamp, featuring an entirely new design, offers split channel operation enabling the user to programme two entirely different sounds or tone variations into separate channels and then enables the guitarist to switch from one to the other by use of a footswitch, utilising a transistor logic circuit for click and noise free operation. The first of the two channels designed primarily as a clean or rhythm channel, offers volume, treble and bass controls, with an optional overdrive facility when used in conjunction with the overall master volume.
The second channel - the boost channel - activated by the footswitch, and visually shown to be in operation by a red LE.D., is designed as the lead channel, and offers the player an immense amount of overdrive and sustain, with a wide variation of tone colours.
Two more controls on the front panel are for: a) the reverb, used in conjunction with a footswitch ON/OFF function, and b) the master volume control. By using the boost channel controls flat out and varying the sound by this master output control, extremely long, rich sustain can be obtained. The inclusion of reverb at this stage will give even more sustain and hall-like spacial effects.
The speaker used in this Combo, is a specially designed 80w 12 inch unit.
Again in line with the increased facilities of the 2000 series of amp heads, the back panel of this Combo offers a very comprehensive range of facilities. Mains input, voltage and output selectors, loud-speaker jacks, a frequency matched D.l. output with its own volume control, send and return sockets for effects units with properly matched circuitry for optimum performance without distortion, and a socket to connect the dual footswitch pedal.