I was thinking of purchasing a hartke bass attack pedal myself. I'm planning on conducting an experimental set-up. I was going to use the hartke bass attack pedal with my rocktron utopia b100 and see what kind of sounds I would with this combination. If it sounds cool(and I'm guessing I would get cool sounds from this combination), I will record sound samples of it and post them on my soundclick website.
Ghostjs, yes the hartke bass attack pedal does provide nice tube sounds. and you can easily dial in a thick growl sound with this preamp pedal. I would know because I've had this pedal once. and I was thinking of buying this pedal again. if you ask me, you'll be getting your money's worth.