Whoops…forgot to add. My ’65 and ’67 amps have had no modifications other then tubes (and I DID replace the opto-couplers on both the Showman and the Deluxe…made the tremolo BEAUTIFUL on both). I bought a new Jensen speaker for the 73 Champ (highly advised). The old Utah they came with sounds like someone farting.

All this talk about which year was labeled Dual in front of the Fender, number of tubes, etc, etc… is useless chatter. I would suggest those who really want to know buy: “FENDER AMPS (THE FIRST 50 YEARS)” . There is basically no rhyme or reason to the way (or time) that Fender did things during these years. Let’s keep in mind the company was sold around ’64 and everything was being revamped by CBS shortly thereafter. Amps changed cabinets, speakers, chassis, knobs, grill cloth, tolex and stenciled names almost daily. Just for shits and giggles, I am staring at the back of my 1967 blackface Showman head (which plainly states: “Showman” on the front…no dual) and it has (from the rear, right to left) : one 7025, three 12AX7’s and four 6L6GC’s. For the “still math challenged” on this site, that’s eight tubes. BTW…it’s one of the sweetest sounding amps you’ve ever heard, regardless of what cabinet or speaker configuration you connect to it (as long as you are matching it’s recommended impedance and not substituting whatever you like..) Don’t be an idiot!!! I have an extensive collection of Fender guitars including a 1960 Jazzmaster, 65 Mustang, 73 Strat, 90’s Tele, 90’s Mexi Strat, and my favorite…the cheapest of the bunch, a Squier Bullet Strat (hardtail). along with the showman is a 1965 Deluxe (non-reverb model..believe me, they sound BETTER…read up on them) and a good old ’73 champ (tip: on a champ, turn the volume all the way up and the bass ALL THE WAY DOWN. Trust me, you’ll be amazed.

Check the # on the output transformer. If the # is 125A30, that is 8 ohms. If the # is 125A29, that is 4 ohms. Another way to tell is to pull the amp out of the cabinet and look at the phase inverter “tail”. That’s the resistor connecting the input circuit to ground, right where the negative feedback loop is attached. A 47 ohm resistor is for 8 ohm output. A 100 ohm resistor is for 4 ohm output. The only other way to tell output impedance is to connect a 4-ohm dummy load to the output and see what the power level is at clipping. If it won’t go any higher than 50 watts, then it’s 8 ohms.