Hi, I wanted to to ask about your experience with Aguilar OPB Preamps, Would you recommend acquiring one for a precision mexican bass? Which of the three OPB's would you recommend ? I´m looking a warmer and deeper sound, and I want to enhance the sustain of my bass. Would you make any suggestions to attain this sound ? My bass has original fender pickups, I'm also considering changing them for precision bass Aguilar pickups or DIMARZIO split.