hi jim!
of course, the settings will be influenced by what bass you are using. i tend to overdrive a little more in moderation, making sure that the more brash tonal qualities emanating from too much presence or high end don't get included in my tone. when it comes to distortion, i want the overdrive to sit just underneath the natural cut of my bass tone, and not dominate it. as strange as it sounds, i try to get the settings to where it sounds like i'm running a separate distortion channel parallel to a clean channel; at least, that's my mindset when i'm trying to set things up. i try to retain as much of the low end as possible, and just create more of a 'midrangey-grind'.
the other thing you have to remember is this... even though you might not thing the tone sounds good on its own just listening to the bass, the way it sits in the mix is going to come across completely different! i learned this in the studio after much trial and error. even though the sound might come across as too dirty on its own, in the scope of the mix it might create a really nice bed. you want to try to use the 'compressed' nature of the overdriven tone to your advantage... even though your dynamic transients may have compressed significantly, it may give the track a particular level of power in context that is actually depending on it.
finally, don't be afraid to boost eq frequencies significantly in order to get the overdrive to work with your bass. also, you'll find that the contour knob will make HUGE differences in your tone because of how it will narrow in on particular frequencies with the distortion...
hope that helps!
