The Ampeg Gemini I, Model G-12 guitar amp features some seldom used tubes for guitar amp design - 12AX7, 6CG7, 7199, and two 7591 power tubes. This example is in good overall condition, but was having reverb (Echo) and tremolo issues and was in general need of a service. It still had all the original power caps, some of which were just flopping around inside the chassis with broken leads, and the original power cord. The tremolo roach was replaced by someone else previously and seems to be the wrong photo resistor for this design. This video series will be in two parts. In this first part we'll explore the features, change power cord, power caps, and troubleshoot the reverb (Echo). In Part 2 we will troubleshoot and fix the tremolo circuit by devising a new photocoupler / optocoupler roach and demonstrate the tone.
6 сен 2024