About ten years ago I built an amplifier for my Kia Rio. I noticed it came with speakers even though I didn’t buy a model with a radio. My amp was a simple circuit that came pre-assembled, required 12 volts and took the signal from my iPod and feed it to the speakers with 22 watts of power.
About two years ago I got rid of that car. But I kept the amp. Today in my new house I am using that amp to power my computer speakers. I am using a pair of Optimus Pro 74V (26-2048). They sound great and can get quite loud with my little amp.
When I first assembled the amp for home use I connected a 12 volt wall wart power suppily (273-1652D) directly to the circuit. But there was a 60hz hum. I though the DC power coming from the wall wart would be very clean, but I was wrong. I then feed the power thru the noise reducer I used while it was powered in the car. It took care of the noise very well.