charger, sound and whining issues

[Anthony28]

I have already accepted that my little fiesta mk6 is going to have to be somewhat of a project top get it up to something i am happy with but it seems on top of the current issues, a new one has cropped up that i could use your advice on. 
After i bought the car i had an auxiliary input installed (official ford part) i have used the input extensively with no problems, aside from a slight crackle from passenger door speaker. This i have put down to a faulty speaker, another job entirely. Anyway, yesterday i plugged my phone in to both the aux in and then the USB charger cable which in turn was plugged in to a usb adapter that fits in the 12volt supply (cigarette lighter). Almost instantly i noticed the sound was slightly distorted and crackly. Still relatively clear but not 100%. The other thing is, when accelerating i can hear a whining/whistling sound from the engine. The higher the revs the louder the noise. If i unplug the charger the noise instantly goes away.

Any suggestions.... alternator issues perhaps?