To be honest, this pedal isn't really going to give you that kind of always on sound. For that you really need to look more towards a lower gain overdrive, perhaps like the Wren & Cuff Phat Phuk B, Catalinbread SFT or maybe a Fulltone Bassdrive. A Sansamp Bassdriver could be just what you're after for an always on kind of low gain sound, with extra EQ control - this is what I bought my MXR M-80 for.
I've had an ODB-3 for years and think it's a great pedal, if you use it properly. With the gain around 11o'clock, blend favouring the clean side and the eq set roughly at 12, you'll get a nice thick bottom to really give some umph in sections where you need it - I would generally roll back the highs slightly and boost the lows too. It's not really that subtle to be honest though so I don't think it's the right pedal for the job, sorry to say.