Head Unit Question
 

I dont know alot My Sony XR-CA630X Cassette Head Unit is old @ the time and i have a new DEH-5900 waiting to be installed, my question is my pioneer has a 4V Preout Voltage & Impedance and my Sony has god knows how much but if it's way less would it make a difference how much power went to my amp and how loud it can go? because @ a certain volume my sub stops playing, im not sure if the amp is shutting off but my in car speakers continue to play.

AMP= Pioneer GM-510T
SUB= Pioneer 12" TS-W306C/SVC

I dont know what the sony is puttin out, prolly 2v, and if thats the case then yes you can turn down your gains abit to achieve the same output from the amp but not have to work it so hard, so it might, MIGHT, not go into protection and you'll be able to get a little more out of it.

if not
 

If its not the deck then could something be tripping? my amp is fine, its grounded properly, the power is tight and my remote is ok.