hey guys, new to talkbass and relatively new to the bass in general...i'm a guitarist by trade but recently picked up a bass from a friend. don't have any amplification though, so i'm in the market for a relatively inexpensive rig. right now the local music store in my town has a GK 400RB head going for $350, and an Ashdown ABM 300 Evo-II for $375, both used. it's a newer-ish 400RB, with the oval around the name on the faceplate, not the older ones with the horizontal power switch. what are you guys' opinions? do these sound like good price points for each? i know from snooping around this site that it seems like a consensus is that the ABM 500 is a better choice, but that's definitely out of my price range. is there really a difference from the older 400RBs to the newer ones with the faceplate i mentioned above? (i seem to have gotten this vibe from people to avoid them) both of these amps are right in my wheelhouse in terms of price and availability, so i'm seeking you guys's expert advice. sorry, i know i'm a noob, but i've been searching the internet for relevant advice and haven't really had much luck. thanks!