The Marshall JTM45 Amp Head is a lovingly created reproduction of Jim Marshall's first amplifier. Now the classic JTM45 is accessible to all who enjoy its glassy, clean tone and fluid, warm sustain. By including GZ34 valve rectification, as found in the original, Marshall has ensured a faithful recreation of the JTM45's glorious sound. The GZ34 rectifier valve interacts with the rest of the valves causing subtle harmonics to shift and smolder beneath every note you play.