Hi all. I'm new to this bass game...having just bought an Ashdown ABM 600 head this morning the treble just stop working for me. The equaliser seems to be ok, just the actual knob not reponding whilst turning up and down. The unit hasn't been banged or dropped..it just went muddy this morning. Any ideas fro. You guys? I've rang the AD up where I bought it from and I can take it back no problem. Just won't be able to get there for a while. Any advice or trouble shooting tips would be appreciated! Cheers. Jim