I just put a modded phono preamp in my system. The company says to give it 50-100 hours to burn in and see how it sounds then. That's a lot of record playing! I thought I could just connect my AM\/FM tuner to it with an attenuator in between to lower the line voltage to equal somewhere in the phono mV range. Then I could let that run for a few days and get that burn in happening a lot faster. Would this work and is it safe? Lowering the level on a line out should be the same as a low level phono out, no? The phono pre-amp can't tell what's providing the signal. It should only care about how high the voltage is, no?