For a three button setup I'd go:
Zoom B3n (I own it): cheap multifx, with some patience you can do more than what you are asking for;
Tech21 SansAmp PSA 2.0 (I own it): fully analogue, already suggested, now cheap, not really an EQ pedal, I suggest you to give a look to the Tech21 bass presets demo.
Two Notes ReVolt Bass Preamp: I don't own it, but it seems to fit your request.
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