This is the last of the original CBS produced Fender Twin Reverbs, and has the highest power output of any regular Twin (this doesn't count the Super Twin or Twin Reverb II which are different beasts entirely) at 135 watts RMS. This was achieved by incorporation an "Ultralinear" design power transformer which has an additional set of taps on the primary windings that connect to the screen grids of the tubes, increasing the output and creating a more "hi-fi" sound. This amp is squeaky clean and painfully loud, both of which are magnified by the factory installed JBL D-120F speakers. These speakers are labelled "Fender Special Design" and feature a distinctive orange and black paint job with massive Alnico magnets. Due to its high power and clean tone this amp is often preferred by pedal steel, country, and jazz players in its unmodified state. Rock players often prefer to modify the amp by having the ultralinear taps disconnected (don't do this yourself unless you're an experienced tube amp tech - there are voltages in the amp that can kill you, even when it's not plugged in) to reduce the output to 85 watts and increase the THD of the power stage. This is often accompanied by circuit changes to the preamp section to alter the amp to the earlier "blackface" spec.
The preamp section features two independent, non footswitchable channels, labelled " Normal" and "Effects". Both channels feature high and low gain inputs, bright switches, and controls for volume, treble, middle, and bass. The effects channel also features tremolo (labelled "vibrato") rate and intensity and reverb depth controls. Tremolo is produced by a photoresistor circuit and reverb is created via a 2 spring long style reverb tank. Effects are footswitchable. There is a Master Volume control with a pull switch for gain boost.
The amp comes equipped with the famous Fender Tilt Back Legs, which allow tilting the amp back for better audibility onstage and projection into the audience, especially on lower stages where the crowd might block sound from the back of the room. (however given the high power and loud volume of this amp I doubt that audience audibility would be much problem. It DOES help a guitarist hear his amp that would otherwise be aimed at his knees.)
4x6L6GC output tubes, 2x 12AT7 tubes (reverb driver and phase inverter), 4x12AX7/7025 tubes (preamps, tremolo oscillator, and reverb amp). Solid State rectifier. Internal hum balance control.
This is not a light amp even with the "normal" Oxford speakers and with the JBLs it is ungodly heavy.. You WILL get a workout hauling it around. Casters (as shown in the picture but not furnished stock) are highly recommended.
A head only version of this amp was produced as the "Dual Showman With Reverb" and a version with 6x10" speakers was sold as the "Fender Super Six".