Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on November 28, 2021, 02:39:54 pm
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I have a Ampeg Gemini 1 and am in the process of installing a new Tremelo Opto from Ampeg Fliptops. I am a bit confused today and my thinker is not working. There is no wiring diagram. I have done this before using the older replacement trem module from fliptops. This new one has me confused. Any wiring suggestions? Purple B+ and Black ground wires on the left. 2 black pot wires to the right.
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Ignore the cell on the left.
Connect the right cell to the pot wires (points X and Y on the schematic). Doesn't matter which wire goes where.
Connect the lamp to the black and violet wires. Doesn't matter which wire goes where.
https://el34world.com/charts/Schematics/files/Ampeg/Ampeg_g12_.pdf
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Ok i'm heating up my solder pencil now. Just don't want to blow it up. Back in a few minutes. Thanks S.
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I have no oscillation. Only 68 volts DC. If i turn the trem switch off i get a rumbling that fades away fairly quickly. When i turn the trem switch on i hear nothing. Have checked tubes for trem 1/2 12AX7 good. All resistor values are within spec. Cathode voltage is 0.875 and 4.50 vdc after footswitch for trem is pushed.
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Got it working. I found the first .047 cap connected to the wrong turret hole. The one without the green wire from the plate V2 12AX7. The voltage shown was before discovery of the .047 being wired wrong. The voltage now is in the 300 vdc range. It sounds decent.
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I just love those old Dubilier caps! I don't see them much nowadays.
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I just love those old Dubilier caps! I don't see them much nowadays.
What always surprises me is that most all these old resistors are so close to spec after all these decades. I have a cap tester and again tone caps as well are almost dead on spec. On the other hand the Astrons were terrible for going south.