Unpacking Each Martin Audio MA series amplifier is built to the highest standard and thoroughly inspected before it leaves the factory. After unpacking the unit, examine it carefully for any signs of transit damage and inform your dealer if such damage is found.
As the output power varies with the load impedance, 4 ohms is usually taken as the reference. Because the MA4.2s is equipped with an MLS-switch there are numerous variations of output power versus sensitivity versus load impedance.
Bridge mono mode Bridge mono mode is used to deliver increased power to the loudspeakers. Using the MA4.2s in bridge mode reduces the number of channels from two to one. The nominal impedance of the load must be more than 3 ohms. Set the Link/bridge switches to the “On” position (UP) and use either of the input connectors A or B.
Danish safety regulation only permits the use of an 8A main fuse. As the MA 4.2s uses an internal primary mains fuse of 15A, the MA4.2s must be equipped with an industrial mains connector rated for 16A or above, or as an alternative it can be hard wired to a 16A capacity circuit and breaker.
Short circuit protection All Martin Audio MA Series amplifiers are completely short circuit protected. The protection circuit permits very high peak currents, but still holds the output devices within the safe operating area. If a sh o rt circuit is ma intaine d , th e cha nn el affe cte d will eve ntua lly g o into a the rm a l prote ct cycle un til th e sh ort circuit ha s b ee n rem ove d.
The MA4.2s uses a power-relay in the soft-start circuit, with a low voltage control switch instead of a high power switch on the front panel. This method of power switching is more reliable and takes up less panel space than a conventional power switch.
In the unlikely event of on a non-user rectifiable fault, return the amplifier to your supplier or an approved service centre. Martin Audio cannot be held responsible for damage or injury as a result of the top cover being removed. 11 WARRANTY General The MA 4.2s Power amplifier is warranted to be free from defects in components and factory workmanship under...