The type of face, grille cloth, type and number of speakers, type and number of knobs, etc.only come into play when you’re trying to value the amplifier in the Blue Book for Guitar Amplifiers per the model description that is provided.
You also mentioned that you’re looking for a speaker option that decreases the overall volume of your amp.
Whether it’s a vintage amp or a recent model such as this Fender Pro Reverb, hum can have several causes.
Possible culprits include the preamp tubes, the power tubes, the hum balance resistors, and the power supply caps.
The following chart, was originally printed in VG magazine, by Gerald Weber.
If you see any data that is not listed here or notice any errors, for 1970’s and earlier Fender amps, please send us an email and we will update the chart.