Musical Fidelity MX-HPA Instruction Manual

MX-HPA Fully Balanced Headphone Amplifier

The ultimate in balanced and single ended headphone listening.

The MX HPA is a very high performance fully balanced Class “A” headphone amplifier in a beautifully designed and executed casework.

The unit features two inputs, balanced and single ended. These are separate and an input select switch allows choice between separate balanced and single-ended sources. These inputs accept normal line-level signals of 300mV nominal (suitable for 30mV- >3V) from a wide range of equipment.

Gain switching is provided to allow boost for higher impedance headphones, so the unit is compatible with all dynamic headphones regardless of impedance. It is recommended to use the LOW setting for headphones of 200 ohms or less; the HIGH setting for headphones over 200 ohms or particularly insensitive headphones.

The front panel XLR/JACK sockets are dual purpose; it is possible to use either one or two pairs of standard 6.25mm ¼” stereo Jackterminated headphones; or a single pair of headphones, terminated in two three-pin male XLR plugs.

The necessary single ended/ balanced mode switching is carried out automatically on connection of the headphone(s).

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Issue 1.1

MX-HPA Fully Balanced Headphone Amplifier

		FRONT VIEW
POWER	GAIN	HEADPHONE OUTPUTS
OFF/STDBY = ☼	HIGH	(AS SINGLE ENDED STEREO JACKS)		VOLUME
ON = ☼	LOW	OUTPUT 1	OUTPUT 2	CONTROL

INPUT SELECT	HEADPHONE OUTPUTS
BALANCED	(AS BALANCED HEADPHONE XLRs)
RCA	LEFT OUT	RIGHT OUT

		REAR VIEW
RIGHT	INPUTS	LEFT

XLR	RCA	XLR	RCA	IEC
BALANCED	RIGHT	BALANCED	LEFT	MAINS
				INLET

XLR SOCKET PINOUTS

	XLR Balanced input
	and output lead	Pin:	Functions: (line input/output)	Functions: (headphone outputs)
	connections:
		1	Ground (cable shielding)	Ground (not necessarily used)
		2	Normal polarity ("hot" or “+”)	Transducer “+”
	(for reference only, no	3	Inverted polarity ("cold" or “-“)	Transducer “-“
	XLR signal leads
	supplied)

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