Diamond Audio Technology D1 250.2, D1 400.1, D1 300.4 installation manual “links” in the circuit

1RCA Input and Pass-Thru Output - These RCA jacks allow for a normal Left and Right channel signal input. Simply connect to the source unit using RCA type audio cables, keeping them away from power wiring wherever possible. On the 4 channel amplifiers (D1 300.4) “Front” and “Rear” input jacks are present. The “Pass-Thru” output allows the signal to pass on to other amplifiers. The Pass-Thru output is unaffected by the onboard crossover.

2Input Gain Adjustment - This control matches the preamp stage of the DAT amplifier to your source unit. This is NOT a volume control. The range is between 150mV and 4V.

3Crossover Adjustment- Use this adjustment to select the crossover point. Remember that your choice will be directed to High Pass or Low Pass depending upon the position of the adjacent switch. The range of adjustment is limited between 40-400 Hz (D1 250.2/D1 300.4) or 40-250Hz (D1 400.1)

4Crossover Selection Switch - This switch allows you to select the crossover. Use High Pass for midrange or high frequency speakers. Use Low Pass for subwoofers. In the OFF position, the crossover adjustment knob has no effect. The D1 400.1 is only available as Low Pass.

5Bass Boost - This control adds 0 to +6dB of boost at 50Hz. Be cautious when adding boost to some subwoofer systems as they may not be able to handle the additional low frequency boost. In the OFF position, no bass boost is added.

6High Level Input - This plug (included) is for use when the source unit does not have an RCA output. Although this is a popular method of connecting a factory car stereo, some systems may require additional adapters. The far left side of the plug is the LEFT channel; the far right side is for the RIGHT channel. The wire in the middle is for chassis ground ONLY if the system is experiencing excessive noise problems.

7the user to control the level of gain up to the maximum adjustment level set on the amplifier. The control does not add additional boost, it only attenuates the setting that is fixed at the amplifier’s control panel.Remote Level Adjustment (D1 400.1 Only) - This port is for the remote level control (included). The control is intended to allow

8 Status LED’s - These lights indicate when the amplifier is powered up normally and when there is a protection fault. See the “Troubleshooting” section for details on what these useful indicators can tell you if there’s a problem.

9Power Input Connections - These connections are for input power, chassis ground, and remote turn-on. Use a minimum of 4 gauge wiring for power and ground connections. The terminals will handle up to 4 gauge wiring with no problem whatsoever. Be sure any wiring that passes through metal has a grommet!

10	Power Fuses - Standard automotive type ATC/ATO fuses are used on DAT D1 Series Amplifiers. Always replace with the correct
	fuse size. Never insert fuses of higher values. Doing so will void the warranty of your DAT amplifier. Also include a main fuse at
	the connection to the vehicle battery within 18 inches (45.7 mm) of the positive battery post. It is also important to upgrade the
	connection between the negative battery post and the chassis of the vehicle. This greatly reduces possibilities of weak electrical
	“links” in the circuit.
11	Speaker Output Terminals - Connect your speakers to these terminals. Stereo connections are connected as labeled. Bridged
	connections use the LEFT + and RIGHT - as the two connections. The 2 and 4 channel amplifiers will perform into 2 Ohm stereo

loads or 4 Ohm bridged loads. DO NOT run 2 Ohm bridged loads on these amplifiers!