Went to the store yesterday to listen to some 6x8 speakers for my 2010 F-150 XLT. The salesman told me something I haven't heard before but I really don't know to much about this stuff. Anyway, he said I can't use an amps high level inputs with my system because the signal going to my speakers is digital and I have to use a line out converter before the amp. Doesn't sound right to me, have you guys heard this before?