This version of the Concert amp was produced between late 1960 and 1963. This version utilized the 6G12-A circuit. As with all of the Concerts during this time, it was also a two-channel amp, but the vibrato circuit had been substantially changed and now required the addition of another preamp tube. In addition, this particular amp has non-original Weber Alnico speakers (see pictures). This Fender Concert Amp is in good working condition. Although we do not regularly sell items like this, we have staff on hand who can answer any questions you may have about the item. So give us a call!