INTRODUCTION
As with all the SERIES TO3 amplifiers, the 4.1HVS uses high voltage to give you maximum power into high speaker loads in order to provide you with maximum performance in your vehicle, not just on the test bench. LINEAR POWER has been designing and building high quality, car audio amplifiers since 1975 in the U.S.A. Now, you have the results of that experience.

Features include: 5-way binding post speaker connections; high current power connector; LINEAR POWER'S exclusive, FMB power supply; configurable PMT circuitry for maximum power into 4 ohm and 8 ohm speaker loads; metal package, military specification, TO3 transistors for the ultimate in performance and reliability; optically isolated power and signal grounds; fan shroud connector; subsonic filter; reversible nameplate; and LINEAR POWER'S reliability and commitment to excellence.

Please read through this entire manual before installing your amplifier in the vehicle. Disconnect the negative (-) battery terminal in your vehicle before making or breaking any connections.

RCA connections: Connect both LEFT and RIGHT inputs with quality patch cords from head unit, preamplifier, crossover, or any sound processor.

Input level: This is not a volume control. This input sensitivity should be adjusted to give you maximum output power while minimizing distortion. To set the input sensitivity, first turn the amp input level control fully counter-clockwise. Turn the source output level up until the signal just starts to distort, then turn the source back down slightly so that the distortion goes away. Now rotate the input level control on the amp clockwise until the signal just starts to distort, then turn the amp input level control back down slightly so that the distortion goes away. This setup procedure allows the source and amp to reach maximum clean output at the same time. For maximum performance and power, the input voltage to the amplifier should not exceed 6.5Vrms.

Speaker connections: These connections are high quality 5-way binding posts. You may connect them with banana plugs, spade connectors, pins, or bare wire. Connect the speaker positive (+) to the left, red binding post and the speaker negative(-) to the right, black binding post.

The minimum recommended speaker load on the 4.1HVS amplifier is 4 ohm. Unlike most car audio amplifiers, the 4.1HVS is designed for maximum power output in BOTH 8 ohm and 4 ohm loads, but you will obtain more output power and better sound with 8 ohm loads due to less strain on the car's electrical system and less heat generated in the amplifier. The 4.1HVS is NOT 2 ohm stable.

The 4.1HVS is shipped from the factory with the PMT circuitry configured for an 8 ohm load. You must change the PMT circuitry configuration inside the amplifier if you are running a 4 ohm load to the positions marked "4". First, remove the silver faceplate/bottom cover. You will see two, plug-on wires directly between the two main transformers and the four large, blue capacitors. Move both of these wires from the positions marked "8" to the positions marked "4" on the circuit board for 4 ohm operation. After making this change, you should readjust the input level control as in (2) above.

The RUMBLE FILTER is shipped in the OFF position, as well. This allows the amplifier to play as low as 10Hz, designed for systems which utilize sealed enclosures. Moving this switch to ON will set the low frequency cut-off to 36Hz, for systems utilizing ported enclosures.

+12V connection: Connect 6 AWG or larger power cable through the supplied inline fuse to the positive (+) terminal on the battery. Position the inline fuse within 18" on the battery. Be sure all connections are secure.

GND connection: Connect 6 AWG or larger power cable directly to a clean, bare metal surface on the car chassis. Use as short a cable run as possible. Be sure all connections are secure.

REM connection: Connect 18 AWG or larger wire to the remote turn-on signal or power antenna signal from the source unit. If you do not have either of these signals available, use the "ignition on" or "accessory" signal to drive a relay that will connect the battery to the rem input on the amplifier when the key is in the ignition. Be sure all connections are secure.

FAN connection: Plug in the optional fan shroud at this location for maximum cooling of your 4.1HVS.

The amplifier will work best if it is kept as cool as possible. Mount the amp in a position that will allow air to flow freely through the fins. Hot air rises, so orienting the amp with the connectors facing the ground and the silver faceplate facing the sky is the ideal mounting position. Be sure there is ample space above the amplifier to avoid trapping heated air against the heatsink. Avoid mounting the amplifier in the dash or on the firewall where sources of noise such as your alternator, windshield wiper motor, and air conditioner radiate the most energy.

NO SOUND: Check all signal input and speaker connections for poor contact or short circuits. Check all power, ground and remote turn-on connections for poor contact or short circuits.

BLOWS FUSES: Check all connections to be sure all power wires do not touch ground or each other. Be sure power connections are not reversed. Check PMT circuitry configuration for proper setting. Check input level control for proper setting.

NOISE PROBLEMS: Be sure the metal sleeves on the RCA (phono) jacks do not touch the metal chassis of the vehicle, the heatsink of the amp, or the chassis of any other components in your installation. Route signal cables away from power wires, power connectors, speaker wires, engine altenator, and vehicle firewall. Keep the length of gnd wire connected to the chassis of the vehicle as short as possible. Connect the +12V wire through the supplied fuse holder directly to the battery (+) terminal as described in +12V connection section.