Oh no not the first or anything like that. I was coming up with all kinds of interpetations as to what that pencil script was.
It might be the woman who wired your amp up.
I had a '55 Tremolux with a small piece of tape inside the chassis between the tube sockets, which let me know it was wired by Eileen. Maybe "Kirst"en wired up your amp. I didn't notice the piece of tape with a name in your chassis.
Does this make sense? 0823 / #82 off the AL. March (3) 1955?
No, because the number on the tube chart is simply the number that's already stamped on the chassis. I seriously doubt the chassis stamping was done at the end of the line; more likely when it was an empty metal shell.
Which means what I've always said: don't read too much into the serial numbers. It is commonly seen in Fender guitar serial number charts that some ranges of number overlap years and/or guitars have numbers which fall outside their supposed year range. Those charts are generally compiled by observation rather than a set of rules.
You're very much better off noting the two-letter date stamp and comparing that with other features in the amp. At least, that was the gold standard for dating tweed Fender amps when I got out of the vintage game in 2000.
Seriously, forget the frickin serial #'s because I never knew a
dealer who put any stock in them (unless they were trying to reel you in and you seemed excited by a serial number). Nashville had a number of vintage guitar shops, and I went to a LOT of shows back before 2000 including a number of very large shows in other states (like the Chicago show, Dallas show, etc) both as a buyer and as help for some friends who were vintage dealers.
I hear another thing you can do is to change the 5U4G rectifiers out for 5Y3 rectifiers for an even more sweet spot.
Don't do that. If you need to tinker, yank a single 5U4.
I haven't found info to state when the 5AR4/GZ34 was introduced, but between tube data sheets and Fender schematics it seems to have come out some time around 1959.
This was a bass amp, and you didn't want sag when you played the low E on your Fender Electric Bass. The 5U4 had the highest current capacity and generally the lowest voltage drop of the 5v rectifiers before the GZ34 was available, and it seems Fender experimented using a pair of them to reduce the voltage drop (because a single 5U4 would handle the current requirements). Fender even used the mercury vapor 83 in the 5F6 Bassman to try to reduce sag even more; after the initial voltage drop a mercury vapor rectifier has very little voltage output change with changing current.
Given Fender used the European designation on its schematics and tube charts, I can't help but wonder if they had tubes pitched to them by the same Philips/Amperex USA folks that were selling ECC83's and EL84/EL34's to U.S. hi-fi manufacturers. Or maybe they were reading industry mags of the day and seeing other manufacturers using the Euro tubes.
I dunno, I guess you can use two 5Y3's, but low sag/hum was the intent of this amp series pretty much from the beginning.
