Quote:
Originally Posted by
hellofishy
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I don't see a 3rd connection?
But looks like its soldered to the metal plate
This is what you'd expect. It's how the case is connected to the cable shield. This screens the internal wiring (and the transformer) of the 57. The voice coil is not well shielded (it's within the plastic bit), so if the mains transformer of the amp isn't shielded either - it's a recipe for hum.