Hi, and thanks for clicking this thread. The upgrade I would do this to is to an ESP LTD C-305 bass that currently has active EMG pickups, and an EMG onboard preamp, I would assume. I'm not sure how many volts it is, maybe somebody could inform me of this. Anyways, I have heard that the "hotter" the pickup, the more headroom you can get. I would be playing this bass thru a Ampeg SVP-PRO rack preamp, BBE 882 compressor, and a Carvin DCM1500 to a SWR Megoliath. Do you think that I would have enough headroom already as is or do you think I should look into a 18V preamp? If so, please put me in the right direction. THANKS!