July 31st, 1998
By: Robert Leidy

After installing the a/d/s/ P840 amplifier I was still having some amplifier heat problems. After discussing the trouble I was having with other people and with a/d/s/ I decided to give up on stereo shop that had been working on my Z3 *Earmark Car Audio in Dallas). Several other Z3 owners as well as a/d/s/ recommended I talk to Custom Sounds in Austin Texas. I eventually gave into my frustration and paid Custom Sounds to fix the problem.

What they discovered was that a couple of the speakers were wired out of phase, some line leveling (or signal knockdown) devices that were not appropriate for use with the a/d/s/ amplifier were installed, and in general the wiring was in their opinion "messy". Custom Sounds cleaned everything up, wired the speakers correctly, removed the signal knockdown devices and also suggested installing some fans just for "overkill" to make sure I wouldn't have any heat related problems. Taking their advice I had them wire a power source for the fans, however they were out of the particular Radio Shack fans they wanted to use so they took the time to show me how to add the fans myself.

On the way home I stopped by Radio shack. The fans were only $9.99 each and I picked up a plug as well so the fans and cover could be unplugged and removed if the need should ever arise. With four fans there is quite a bit of air flow directly over the amp. The fans are attached under the facade but blow air through the groves in the heat sink. It is a very productive setup, the fans are quiet and do not affect the sound quality.

While at Radio shack I also picked up a fancy digital thermometer that has two separate temperature sensors. I used this device to measure the temperature directly over the amp as well as in the corner of the trunk. After comparing these temperatures to those I took from other Z3s I'm ready to declare the heat problem resolved.

Six Month Update