Dating fender amp pots
The AC coming in is at 335 volts you would expect that of a 70`s power transformer.
The one I HAVE IN THERE JUST HAPPENS TO FIT THE DATES OF ALL THE OTHER DATE CODES IN THE AMP.
if otherwise verifiable as a 1966 Fender (tubechart stamp, potcodes, etc), and your power trans says 606-6-25, and it doesn't appear to have been replaced, then i'd say you have an intact 1966 Fender.
The problem (well its a matter of preference)is my power transformer with a GZ34 makes those 6v6`s run about 435.
The minuses are between all the pots, output transformers and chokes.
the "606" is the id of Schumacher Electronics (the manufacturer of almost all Fender power and output and reverb transformers since about 1960-61).
the "-6-nn" or "-6nn" is the last digit of the year (0 thru 9), and the week within the year (with nn=01 thru 52).
I said check the serial number and they said they couldn't find the year by looking at the serial number. I hvae been to the site and couldn't find any e-mail links. The number is B-045190 for anyone who might know.(its a Fender Hot Rod Deluxe)They started making those amps in 1996. The transformers, the speakers, the pots all have manufacturer codes that date them. I discovered this because the letter on the serial number I have, is a 1991 model.