[quote name='daz' timestamp='1336189693' post='1642317']
Billy Sheehan swears by it. He says as he usually practices with his bass unplugged, that the amount of high to low is much less than when plugged in, so he reigns it back in with a compressor.
The result being his practice sound is nearer to what it sounds like on stage, just different in volume.
[/quote]
Very much this. I won't play without a compressor, I've been through all the fancy ones and ended up back with a trusty old boss cs3.
I just like the way it provides a nice, consistent, even response, adds sparkle and attack and increases touch sensitivity. I don't find any lack of dynamics at all. Any slightly negative effect on tone is so slight in a band mix as to be a non issue. But I just find its become such a part of my whole technique and sound.
If you're the sort of player to switch between fingers and thumb, harmonics and tapping etc all in the course of a song it's a really handy tool.
I leave one in my bass bag