Dating a fender amps by transformer
That’s probably a moot point, though—experience tells me that most original speakers in amps of that age are substantially fatigued and generally sound very weak. It's a great-sounding speaker, but with a sensitivity rating of 100 d B, it’s relatively efficient and would probably be pretty loud in that amp.
Let’s take a look at a couple speakers from Warehouse Guitar Speakers (wgs4.com) so I can better explain this.
If you are unsure of this procedure, consult your local amp tech.
(I’ve also included a few others brands you might encounter as aftermarket installations.) This should help you identify your speaker.
You also mentioned that you’re looking for a speaker option that decreases the overall volume of your amp.
But I don't think this is correct since Fender did not make the '65 Twin Reverb until 1991. many thanks._________________"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKYHi robes, The "A" that Fender is referring to is part of a two letter code usually written on the sticker on the back of the chassis.
The first letter is the year (A=1990), and the second letter is the month (A=January). You might have to remove the chassis to be able to see the sticker, or use a mirror on a telescoping arm.