I have a SWR WM 12, and I'm using an accusound pickup ( http://www.accusound.com/double-bass.htm ). I recetly read that 'francois' uses an extension cable with this amp - what is and what are the benefits of using this cable. Also does anyone find that this amp does not have enough volume for a medium sized pub gig? Is there any way to get more form the amp? Thanks.