MP3Car.com - View Single Post - FAQ: Connecting your soundcard to a Volkswagen Monsoon Amp

kb1gtt · 07-08-2007, 07:21 PM

Yes I've had the same problem. Ground the LF- line and the amp will turn off. I found a 1kohm resistor from LF- to GND works well as a permanent fix. The resistor won't affect your speaker level audio signal but will pull the line to 0V and turn the amp off when the radio doesn't drive the LF- hard enough.

Your problem is that some voltage is getting on the LF- line keeping it above about 3V. This can be caused by radio signals and long wires picking up the voltage out of the air, it can be caused by small amounts of leakage current from a number of electrical devices, or it can happen because it wasn't given a chance to go somewhere else. A meter is basically a resistor with a meter across it, so if you put a volt meter across LF- and GND, the meter will probably cause enough of a pull to ground to make the amp turn off.

It's now been several weeks, and we have had no problems with a dead battery.

07-08-2007, 07:21 PM	#58
kb1gtt Newbie Join Date: May 2007 Posts: 6	Yes I've had the same problem. Ground the LF- line and the amp will turn off. I found a 1kohm resistor from LF- to GND works well as a permanent fix. The resistor won't affect your speaker level audio signal but will pull the line to 0V and turn the amp off when the radio doesn't drive the LF- hard enough. Your problem is that some voltage is getting on the LF- line keeping it above about 3V. This can be caused by radio signals and long wires picking up the voltage out of the air, it can be caused by small amounts of leakage current from a number of electrical devices, or it can happen because it wasn't given a chance to go somewhere else. A meter is basically a resistor with a meter across it, so if you put a volt meter across LF- and GND, the meter will probably cause enough of a pull to ground to make the amp turn off. It's now been several weeks, and we have had no problems with a dead battery. Last edited by kb1gtt; 07-08-2007 at 07:24 PM.