For sale an excellent condition MarkBass R500 head !!! It is a very unique head produced by MarkBass that can go from grint to full on overdrive with the 12Ax7 preamp tube. It is a superb amp ( as any other MarkBass products ) and weighs next to nothing !!! A breeze to carry after a gig !!! It has very minor scratches on the top, nothing to worry about, very minor. Email for questions. Asking 425$ shipped US or Canada.