Why do you think the Sony would be power hungry? I have a fairly up to date Sony CDX GT300S with inputs for iPod and auxiliaries. It consumes 0.8 amp with a CD playing, less with just the radio.
Hi, Maybe you can help? We have just purchased a Sony radio to replace the Blaupunkt on our yacht purely to have an aux jack so that we can use our ipods etc with the radio speakers which are wired in the cockpit and down below. We're now having problems getting power to the 'panel'. There's power in because there's a whirring where the CD would be inserted but there's no display. In order to get power to the unit we had to invert the yellow and red wires as per Sony instructions. At a loss to what we have done wrong. We appear to have two power wires coming from the boat (i.e. red and black) but the new radio requires 3 i.e. red, yellow and black. Any ideas? Many thanks Claire on s/y Ocean Rainbow - currently in Guadeloupe!
From elementary electrical theory, an amplifier/radio/mp3 player producing 12 watts of sound, will draw more than one amp of current from a 12v battery (P=iV + inefficiency losses). Of course there are complications such as "perceived" power, and "music power", used by manufacturers to exaggerate performance.
Also, manufacturers of such equipment design it for the automotive market, where the electrical system is fed from the vehicle alternator, and is essentially limitless in capacity. For that reason, frugality is not an issue in design.