I'm reluctantly parting with my old friend, the V-Twin. They haven't been in production for a looooong time, but I haven't used mine regularly for a while, either. I have too many other pedals/od's/preamps, etc...!
The V-Twin was intended for guitar use, but it kills on bass as well! The eq points work well & the low-end is great. There is far less low-end loss than many other bass-specific overdrives + the bass eq lets you dial in all the lows you need! The sounds range from completely clean tube richness (green channel), to natural sounding transparent overdrive (blue channel), to all out Mesa-style tube distortion (red channel).
http://www.mesaboogie.com/Product_In...in/v-twin.html
I have used this pedal in the past very effectively as a stand-alone studio pre for bass. It's also a great sounding overdrive/distortion! There are 2 12ax7 tubes, so you can customize the pedals sound even further. The V-Twin makes a great headphone amp as well - it's a super flexible unit.
Here's an old thread of mine w/ a few clips:
Mesa V-Twin for bass??? w/ clips!
This is the original version w/ the dome knobs & no clean trim mod. Comes with original Mesa power supply that my old tech lengthened for me. There are some scuffs and scratches, but it still looks pretty darn great (see pics). Also, I no longer have the feet (it was mounted on a pedalboard for a while & one of the foot-screws is broken off. Everything works 100% and sounds great!
Pics:
Price is $275 shipped via USPS to the 48 Contiguous US states. Paypal only, please! 
