http://www.ampwares.com/ffg/
Silver face amps mostly used a 5U4GB rectifier as stock. A GZ34/5AR4 was stock in blackface amps, you can use a GZ34 to get closer to the blackface tone (i.e. less sag). pstring got the rest of the tubes correct. You can use other power tubes also (6L6GB, 5881, 7581) with different effects - always re-bias when changing power and/or rectifier tubes. You can also try other preamp tubes for subtle tone changes - but don't use anything but a 12AT7 in the reverb driver slot (3rd from right looking at the back of the amp). That overdrive you hear at 5 on the volume is a good thing.
Check this website for a description of the preamp tubes in a Fender amp.
http://www.kcanostubes.com/layout.htm
That's a great amp at an incredible price. I strongly recommend that you find out if the electrolytic capacitors have been changed (cap job) in the last 10 years. If not, get it done ASAP. You may want to "blackface" the amp at the same time if a tech already has it opened up.
I've had a '74 silver face Super Reverb for almost 30 years now. I blackfaced it 3 years ago and it made a great amp even better.
Any other ???'s you have, ask away.
[Edited by John O'Carroll on 10-08-2003 at 10:20 AM]
