Musical Fidelity AMS50 manual Installation, Setting UP

AMS50 INSTALLATION

SETTING UP

Position the AMS50 on a stable, horizontal surface where there is no risk of it being knocked.

Make sure ALL units involved are switched off and unplugged from mains supply before making or removing any connections.

During normal use, a class A amplifier, such as the AMS50, develops an appreciable amount of internal heat. It should therefore be sensibly situated where it can radiate this heat most efficiently. If this is not realised, heat build-up will occur and may cause the amplifier to shut itself down. It is thus recommend that the unit is situated in an open rather than enclosed space and away from other sources of heat.

AUDIO CONNECTIONS

Inputs: The AMS50 has a pair of RCA (single ended), and XLR (balanced) level inputs. Choose which inputs are to be used. It is recommended using the XLR inputs if your preamp features XLR balanced outputs to obtain maximum benefits of the balanced circuits.

Either the RCA or XLR inputs can be used at any one time. It is not possible, for example, to connect both RCA and XLR sources and use the switch to select between the two.

FOR XLR INPUTS:

The XLR balanced input allows direct connection from a pre-amplifier’s balanced outputs where available. This provides a trap for external noise and distortion artefacts whilst allowing the signal through completely unaffected.

Make sure the RCA/XLR selector slide switch on the back panel is set correspondingly (down).

FOR RCA INPUT:

The RCA line input allows connection from a preamplifier or amplifier’s preamp RCA (single ended) outputs.

Use phono to phono cables to connect the left and right outputs on the preamplifier outputs to the left and right line level inputs on the AMS50.

Make sure the RCA/XLR selector slide switch on the back panel is set correspondingly (up).

Note: in both input cases it is assumed that the driving preamplifier has a VOLUME CONTROL to allow setting of listening level. This is important as the AMS50 has no volume control of its own.

OUTPUTS:

Connect loudspeakers to the terminals near the base of the back panel marked as OUTPUTs. Make sure (+) lead from amplifier speaker output goes to (+) lead on speaker terminals, and (-) to (-). It is most important to get the phase of these leads correct.

MAINS POWER INPUT

Check the rear panel mains switch is set to “off”. Connect the supplied mains lead to the IEC socket near base of back panel. Connect the other end to a mains power socket.

TRIGGER INPUT

A remote triggering input is available to allow the amplifier to be turned on automatically by other equipment. This is a 2-way 3.5mm jack on the back of the unit labelled “TRIGGER”. It requires 5 to 12V (either polarity) to switch the amplifier on. Such a trigger signal is available from (for example) most home theatre setups.

Note: The trigger input acts as override to the front panel push switch only. The unit will need to be switched ‘on’ using the rocker switch at the back in order for the trigger input to work.

CAUTION!!

This unit features a BRIDGED output and should NOT be grounded on either output terminal as both are effectively “hot”. Please check if using any active “sub”, electrostatic, or other non standard speaker types directly connected to the outputs of the AMS50. Consult speaker manual or supplier if in doubt.

Additional note-

If bi-amping, please ensure that speaker shorting links linking treble and bass units are removed. Failure to do so may result in damage to connected amplifier(s) and/or the AMS50 itself. See loudspeaker instructions for more information.

CLEANING

Before cleaning the unit, switch off power at the mains switch and remove the mains plug from the wall socket. Clean the cabinet and remote control unit using a moist cloth. We do not advise using solvents, white spirit or thinners as they could damage the surface finish.

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