Technical - MP21 & MP21R Combo Guitar Amps
Gig-Proof® Design Features
The power amplifier is installed in the bottom of the cabinet to provide maximum stability.
The chassis has been engineered to provide extreme strength and ruggedness.
Its main beams carry the transformers and choke, and provide the support for the resiliently mounted power-amp sub frame which isolates the valves from shock and vibration.
The power amplifier is completely hand-wired, using high quality tag boards and arranged so that all components are easily visible and readily accessible in the unlikely event that repairs are ever required.
The power amplifier can be remotely controlled from the pre-amp to work in either high power (pentode/tetrode) mode or low power (triode) mode, delivering around 55W or 20W respectively. Low power mode, as well as offering the full tonality of the amp at lower sound levels (good for practice and studio sessions) also provides interesting early output stage break-up and a rich even-order harmonic response particularly suitable for jazz and blues solos.
High power mode offers a traditional range of tone at a higher sound level, with the more typical pentode overdriven characteristic, with a higher proportion of odd-order harmonic content appropriate for rhythm work and heavier rock solo performances.
The power amplifier may be fitted with any of the commonly available output valves.
The amp will need re-biasing for alternative tube types, but we have provided bias test points, and bias adjust pots which are accessible without having to remove the chassis from the cabinet. Full instructions for biasing the amp to suit any valve combination are contained in the user manual, and separate bias pots mean that there is no need to purchase balanced pairs of output valves, as they may easily be balanced in the amp.
The power amplifier has been provided with a dedicated earth bond terminal to ease PAT safety testing, which is an increasingly important requirement at many venues.
The amplifier is designed to provide maximum power into an 8 ohm loudspeaker load. The amp will however tolerate any load between 4 - 16 ohms without damage, albeit with reduced power output.
An auxiliary output jack socket is provided to allow an additional speaker cabinet to be coupled up if desired.
The power amplifier is provided with an IEC switched socket inlet, incorporating a power-on neon indicator and a mains power fuse. A spare fuse is located in the fuse carrier drawer.
A mains voltage selector switch is fitted behind a recess on the rear plate, and an input voltage of either 115v or 230v may be selected.
Gig-Proof® Design Features
The pre-amplifiers are based on a substantial 19" rack-mount enclosure which may be fitted into standard equipment racks. When purchased as part of a combo system, however, this feature would not normally be used.
As in the power amplifier, the main sub frame which carries the valves and associated components is resiliently mounted to minimise microphonics and the risk of vibration /shock damage to the valves. If the pre-amp includes reverb, the spring line is also resiliently mounted within the enclosure.
The pre-amplifiers are also completely hand-wired, using high quality tag boards and arranged so that all components are easily visible and readily accessible in the unlikely event that repairs are ever required.
Various pre-amps are available offering different features and facilities, but all are plug-in compatible with the power amp, and interchangeable, offering an upgrade option for the future.
The pre-amps all provide 3-band passive tone control, with Bass, Middle and Treble controls, switch selectable input gain, variable input gain and master volume controls.
The pre-amps have a pair of jack sockets to allow connection of external effects units such as a series FX loop.
Some units also have a socket to allow connection of a footswitch for channel and Reverb selection.
The pre-amps have been designed so that residual hum and noise is reduced to almost imperceptible levels.
Maughan amplifier combos come with a hand built cabinet, either in a solid hardwood of your choice with a high quality polished tough lacquer finish, or in high grade vinyl covered plywood (again a choice of colour and texture is available).
All cabinets may be fitted with any of a variety of loudspeaker drive units to suit individual tastes, and all feature our unique DiffusionGrille®. This specially selected grille material modifies the directional beam effect of the loudspeaker, and de-focuses the sound to ensure maximum coverage and distribution of the amplifier's output.
As the gig progresses, and the audience gets up and starts to dance in front of the band, those still sitting at the back can hear every nuance of your performance, (even though they can no longer see you or your amp!).