weaver@silver.DEC (Dave Weaver, DTN 231-7141) (09/27/84)
Could someone explain some of the interfacing problems in amplifying speaker level outputs using a booster or amplifier in a car stereo system. In particular I am trying to interface an Alpine 40 watt amplifier to a high-end Clarion factory AM/FM Diversity Cassette Receiver. I don't yet have the specs on the receiver (it came in my new '84 Nissan Stanza) but I suspect that it around an 8-9 watt receiver. When I get the schematics, I will probably modify the receiver to provide pre-amp outputs. In case I can't get at the pre-amp, I am trying to develop an alternate strategy, so I would like to know about different grounding problems that may occur as well as the best way to reduce the voltage levels to something that the amp will take without introducing any more distortion. Note that the Clarion has an EQ loop and tape input, so it probably has a well defined pre-amp section. Alpine makes an adaptor for there bi-level receivers to allow them to use speaker outputs into the amplifier which appears to just consist of some fairly hefty resistors. I think the impedence load is too great for the amps in the receiver, because it tends to clip a lot, so I would be interested in ways to keep the impedence low. Note that the speaker outputs from the receiver have separate grounds for each of the 4 channels. Without the specs I can't provide much more info. I am currently attempting to put the Alpine on the left and right rear channels so I can run a pair of Boston Acoustics C700's. Thanks in advance, -Dave decwrl!rhea!silver!weaver