hey, I have the b20 which I find just ok. I'm playing a mij fretless jazz bass and I've always felt that the amp doesn't deliver authority or a nice defined sound. And now it's rattling a bit. I've been wondering if the rumble 40 or ampeg 110 are a worthwhile upgrade or one needs to get into pricier stuff. This is simply for playing at home and some jams with friends so no real need for watts, just quality... The bass sounds quite nice through a good di and monitors, so the qualities I'm looking for are present in the bass, I just can't hear them through the b20. I'm also open to used amps, love me some second hand gear.