Protection Circuitry

Your REFERENCE404s amplifier is protected against both overheating and short circuits by means of the following circuits:

∙Auto High Current™ power supply

∙Main power supply fuses

∙Circuit breaker on each channel

∙Smart Power Supply Thermal Rollback activating at 85°C

∙A fail-safe thermal protection circuit activating at 95°C.

Your amplifier also incorporates an innovative Fault Diagnosis system that identifies a blown power supply fuse.

NOTE: If you experience blown main power supply fuses, DO NOT increase values beyond the original fuse value! Doing so will void your warranty and

TROUBLESHOOTING

	PROBLEM	CAUSE

	No sound and LEDs	∙ no power or ground at amp
	are not lit	∙ no remote turn-on signal
		∙ no remote turn-on signal
		∙ blown fuse near battery

	Fault LED is lit	∙ amp power supply fuse is blown or missing

	Repeatedly blown	∙ speaker or leads may be shorted
	amp fuse, frequent	∙ verify adequate amplifier ventilation
	activation of Smart	∙ verify adequate amplifier ventilation
	activation of Smart
	Power Supply Circuit

	Channels 1,2,3 or 4	∙ activation of the internal circuit breakers.
	experiencing inter-	∙ check to make sure channels 1-4 are driving a
	mittent output	∙ check to make sure channels 1-4 are driving a
	mittent output	1/2 ohm per channel load or greater
		1/2 ohm per channel load or greater
		∙ speaker or leads may be shorted

	No output from	∙ Select "Internal from ch's 1 & 2" on Ch 3 & 4
	channels 3 & 4 with	input on the bottom of the amplifier. (see
	1 pair of RCA inputs	pages 14 - 17)

TABLE OF CONTENTS
Design Features	4 - 5
REFERENCE404s Diagram	6 - 7
Auto High Current™ Power Supply	8
Selecting Input Modes	9
Wiring (with Diagram)	10 - 11
Installation and Mounting	12
Level Setting	13
System Installation Diagrams	14 -17
Protection Circuitry	18
Troubleshooting	18
Service	19
Specifications	19