I have a strange and annoying habit of learning lessons the hard way. In this case, it has to do preamps, and the Department of Redundancy Department. I forgot the MIT acronym KISS- Keep It Simple, Stupid! I have a Hohner B2AV-WS Headless 5-String Bass, into which I have installed an Aguilar OBP-3 preamp. Seemed like a good idea at the time. My amp head, a Baby Blue II head also has a tube preamp- very complex, but useful in tone-shaping. Right now I am awaiting delivery of a Viva Analog 360+ Lite preamp/fx pedal, in hopes of capturing that Jaco sound. Then I realized that I will wind up with 3 levels of pre-amplification. So I will need to flatten the t, m and b controls on the OBP to send a dry signal to the 360+. Since I want to get my moneys worth out of the 360+, I will first play with that one until I get the sound I want. Then I should set the BB II to bypass the preamp section, and feed the signal directly to the power amp. I might then carefully play with the OBP-3 on board the bass to enhance the process. Finally, if I can bring the BB II preamp online without totally trashing the audio signal quality, that would go last. For any other newbies who may get carried away, I hope my experience will be useful; for the old-timers, any further advice would be appreciated.