In this video we will follow the diagnosis and service of an unusually labeled Gregory-made Prestige series filament, vintage tube guitar amplifier. Gregory amps were made in New Jersey and usually featured point-to-point wiring. This example from 1966, however, has a small printed circuit board. Tube compliment is also unusual for their small Mark I and Mark II amps in that instead of a 12AU7 or 12AV7 pentode, there is a 12AX7 up front, with a 50C5 and 35W4 rectifier tube. At the end of the video, we will take a listen with both a Silvertone Harmony and a Fender Telecaster.