with a front panel that had a rectangular grill cloth with rounded corners and looked much like a television of that era.In 1953 the cabinet designs were changed to the so-called "Wide Panel" design, with a 5 inch wide tweed covered panel above and below a wider swath of grill cloth.
The power amp included a "long tailed pair" phase inverter, an innovation that noticeably increased the "headroom" or clean power output capability of the amplifier.
Similar preamp changes were also incorporated in the 5F8 Twin Amp at about the same time, but not on other large size Fender amps.
The lowest serial number known to still exist is 0013 (Frank Roy), but 0035 (Albert Talley), 0075 (Jim Cornett), 0077 (Perry Tate), 0089 (Mark Grandfield), 0701, 0745 (Walter Horton), 0769 (Hayes Kolb), 0780 (sold on e Bay Nov 2006), 0783, and 0785 (Hayes Kolb) are among those still known to exist.
These rare few are known to sound better than the revered 1959 5F6-A circuit.
The LTD came equipped with the original 5AR4 rectifier tube, and four Jensen P10R reissue alnico speakers, which was period correct for the original amp.