Just like the title says, is there a way I can add a Bass **** on the amp? It's the older version 250/1 amp.

 

You can add an off board unit, but not recommended, the 250/1 did not have the RBP plug, it had a set of pre-amp outputs, the pre-amp outputs have been replaced with a RBP on the 250/1v2.

Does your HU not have a "sub out" with gain control? 94