Musical Fidelity manual AMS50AMPLIFIER SPECIFICATIONS, Problem, Probable Cause, Remedy

AMS50AMPLIFIER SPECIFICATIONS

Basic problem-solving with an amplifier is similar to troubleshooting other electrical or electronic equipment. Always check the most obvious possible causes first, such as the following examples:

Problem	Probable Cause	Remedy
No power when POWER switched	Mains power plug is not fully inserted	Plug in securely
turned on	into rear socket
	No mains power	Check socket with another appliance
Unit not coming on via TRIGGER	Mains power not present	Check unit is plugged in and switched
input		on (back panel switch).
	Trigger lead disconnected	Check lead is fully connected and
	Triggering unit not sending trigger	triggering unit is on and sending a
	signal	trigger signal (±5 to 12V nominal)
Noisy or reduced sound	Wrong input selected	Move RCA/XLR switch to correct
		position
	Both RCA and XLR inputs connected	Remove unwanted source.
	to source(s)
Sound is not precise, lacking in bass	Speakers are connected out of phase,	Ensure speakers are connected
and stereo image (when used in	i.e., connections to one speaker (+	correctly:
conjunction with other unit(s))	and -) are reversed on one or more	+ terminal on amplifier goes to +
	units	terminal on speaker,
		- terminal on amplifier goes to –
		terminal on speaker.
		Note: Most cables have polarity
		markings to help get this right.
Unit cuts out, orange LED lit	Overheating	Make sure unit is situated to allow
		free air circulation. Allow to cool
		down before attempting to switch on
		again
Flashing RED LED	Short circuit in speaker (output) leads	Check speaker leads connected to
		SPEAKER OUTs on AMS50 and
		speaker ends for stray strands or short
		circuits.
	Problem in speakers	Check speakers and wiring.
	Grounded via speaker	Wait 30 seconds before switching
		back on, and apply music source.
		Both the + and – speaker output
		terminals on this unit are “hot”. Some
		speakers e.g. active subs and
		electrostatics have “grounded” inputs.
		Such speakers are incompatible with
		the AMS50.
Hum	Audio connector plug not fully	Insert plug securely
	pushed in	Move input switch to correct position
	Input not correctly selected	Check cable is connected at both
	Cable Fault	ends.
	Unsuitable Cable	N.B. some esoteric cables have
	(e.g. cable grounds not connected)	internal wiring intentionally
		disconnected/modified. For best
		results on all inputs, please use good
		quality straight- through cables,
		signal lead(s) directly connected at
		both ends and earth/screen(s) directly
		connected at both ends.

If none of these actions affect a cure, please contact your dealer, or an authorised Musical Fidelity service agent. Remember; never open the case of the AMS50 yourself, as this will invalidate the guarantee.

Issue 1 Page 9 of 12