When using a radio transmitter with my iPod, I learned that it’s best to set the volume at around 75% and use the radio volume controls instead for fine tuning. If you set the iPod volume to max, it comes out staticy and distorted. I’ve noticed a similar phenomenon when using the line out to my tv - although there’s no static, there is audio distortion. Why does this happen?
Line levels on audio equipment are expected to be under a certain voltage. That voltage seems to vary. I seem to recall its supposed to be 1 mW at 600 ohms or about .77 volts RMS but some equipment can take more than that and some less. If the output signal from the ipod goes over that voltage then the signal will be clipped which can sound like static.