This past summer I purchased a brand new 65 Princeton Reverb Reissue for my son and the tone/volume mix is glorious. I just purchased a used 65 Princeton Reverb Reissue (serial number look up says it's from 9/2008) which has the same speaker and - according to Fender (also via serial number lookup) - the same specs....but it is painfully loud. Like, on 1.5/2 it's louder than the my son's PRRI on 4/5. I can see NOTHING different except one tube being not GT make, but my thinking was that a diff tube brand might - at most - affect tone slightly.
Is it even possible for someone to have done something under the hood to make the amp this loud? The variance between the two amps seems too extreme to be just a nuance of circuitry...but that's why I'm asking the experts here.