I'm referring to the not-favorable results when I installed a buffer preamp into a passive Precision-style bass. The idea was to simply boost the output of the P-bass to match the active preamp output of my Jazz-style bass. I would like to use one transmitter with both basses. I absolutely love the tone of this bass, I'd just like more output. I've pulled the trim controls in the Jazz-style bass all the way down, but it's still considerable hotter than the P-style bass. So I installed a Bartolini AGB/918-2 buffer preamp into the P bass tonight. The preamp is described by Bart as an adjustable-gain buffer preamp. No tone controls. The results were not good. The tone now was very bright, very harsh. I immediately uninstalled the preamp and rewired the P bass to its stock form. So where did I go wrong? Do the values of the tone control and/or the capacitor on the tone control need to be considered because of the preamp? I doubt I'll try this experiment again anytime soon, but I'd like to know how to proceed should I decide otherwise. I looked at the John East P bass preamp which is a drop-in unit and requires an external source to charge the internal battery which is kinda odd. Besides, John East has pulled that preamp off of the market, citing a need to redesign the battery system. Thanx for any guidance.