I spoke to someone at work who reckoned my minidisc wouldn't supply enough power to the amp to be able to hear anything. I thought that this would be the same as the empeg, then.
Depends on your definition of "power".
If you mean electricity going down the main 12-volt power line that feeds the amplifier, uh, yeah. You should be powering the amplifier straight from the car's battery as I said in my first reply.
If you mean voltage on the audio outputs, it's likely to be just the opposite of what your co-worker said...
See, the audio outputs for car stereos and car amplifiers is meant to be something called LINE LEVEL OUTPUTS, meaning there is little or no actual amplification on the audio outputs. The head unit doesn't supply any power to drive speakers, that's the job of the amplifier.
If you've got a hand-held portable Minidisc, it probably just has some HEADPHONE OUTPUTS which are actually amplified. They aren't amplified very much, as they're only intended to drive a tiny pair of headphone speakers, but it's still more than line level. Usually, headphone outputs plugged into a line-level input are distorted because they are supplying too much signal.
In some cases, you can simply turn down the volume on the headphone output and get an acceptable sound, so that might be an option for you. The only problem is that your portable minidisc doesn't have a remote amp-turn-on lead that you can use to activate your car amplifier.
I'm not sure if it's safe to temporarily wire the blue amp-remote line to a switch connected to a 12v source. I don't know if that's kosher or not. I know the amp remote line isn't intended to carry a any voltage at all. I wouldn't recommend trying that without first talking to an installation expert.
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Tony Fabris