Converting Forte Model 3 to Model 1a

[LouieTheG]

I believe I saw a post by Nelson some time ago that all that is required to convert a Model 3 to a Model 1a is to change the power supply ground plane and increase the bias. Is this correct and can someone help me with a schematic or other docs? I own both amps and want to convert the Model 3 to a Model 1a to use in a vertical biamp setup.

 

[Nelson Pass]

You want a lower voltage and a higher bias, that's about it. If you are at
120V, I think you can tap the transformer primary for 240 and run it at 120,
and that will lower the voltage.

 

[LouieTheG]

Thank you, Nelson!