Really not clear what you mean here by "purpose". My bass amp has a 1MOhm input impedance. Plugging my NXT directly into it "works", but the dynamic envelope and sonic detail is *much* better with the Fishman in the chain ahead of it. Yes, that means I've got two tone stacks (fortunately, on my bass amp, there's an EQ bypass switch), and an extra volume control (I tend to set the Fishman to deliver something reasonable and modulate with the amp, just 'cos it's easier to reach on stage). I suppose I *could* run the Fishman directly into the FX return on the amp, to bypass the built-in pre-amp and have a very slightly better signal/noise ratio, but for practical purposes just plugging it into the lower impedance is the minimum change to what I do with my other basses, so I stick with that signal flow. If I were going into a PA or a recording console, I'd just run the Fishman straight into the board.