The 500. With those rumbles, we don’t have the option of an active input jack. I was just noticing that my stingray and bongo sounded louder when I use that combo. I’ve also gone amp crazy the last year. I would bet my other amps would be really loud to if I plugged my basses into the passive input. Remember, active basses are still kind of new to me, and I haven’t tried plugging them into the passive input jack yet only because I was under the impression you weren’t supposed to. But I guess I can