iPod Dock Connector Question for Car Audio

[horigan]

I'm trying to set up my Nakamichi deck with Aux In to accept my Gen 4 iPod with a dock connector adapter that both charges and reads the line out signal from the bottom. The only product I've found that does this for my deck is the Soundgate Universal RCA adapter that plugs into the dock connector and has RCA outputs and positive and negative lead wires to connect to 12V power in the car. The only voltage protection for the iPod is a fuse in the power line.

The reason I'm doing this verses charging with a regular car charger and using the headphone jack is 1) reduce the wires in my car, 2) eliminate having to use two volume controls, and 3) I've heard the dock connector has got a fuller frequency response that's not targeted to headphones.

My question is - Is the 12V power with fuse sufficient voltage protection for the iPod? I've opened other chargers and there is circuitry consisting of resistors and capacitors that I suspect is there to protect the iPod circuitry from vehicle voltage spikes or if the plug is pulled with power on. I've measured the voltage coming from a USB car charger and all I could get was 5.5V.

Thanks, Rich