The Western Electric 1140A Amplifier is a push pull parallel 25L6GT design with out a power transformer. The inputs and outputs are isolated from the AC line by audio transformers, on both the input and output of the amplifier. Contact with the line power circuitry is prevented by a metal cabinet, which is grounded by the green protective ground wire of a 3 wire line cord. The actual amplifier chassis is mounted within the cabinet and isolated from it by insulating strips. The amplifier chassis is connected to the amplifier circuit ground by a 0.1 uf capacitor.
I will post the performance specifications for Western Electric 140A in the next couple of days, along with more details on its design.
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