The trimmers you see are for the constant current source in the FET voltage gain stage. Do NOT adjust these when you switch tubes. Did you know that all the gain in that model is provided by the solid state FETs? The tubes are used as cathode followers and do not provide any gain. They are there so that ARC can market it as a tube line stage.
ARC LS25 mkII adjustment
Does anyone know the procedure to adjust the LS25 mkII preamp? I am considering swapping tubes with new ones and would like to know how to adjust the 2 trimmers that looks like sets the voltage for the tube bias.
I don't have any documentation on where to measure and what to set to. Anyone have any experience with this preamp?
I don't have any documentation on where to measure and what to set to. Anyone have any experience with this preamp?
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- 12 posts total
- 12 posts total