Would someone explain why some preamps invert polarity? Seems it would be just as easy to not wire them that way. Thanks.A typically designed gain stage in a component having an unbalanced signal path, whether tube or solid state, will invert polarity. If there is an odd number of such stages, such as 1 or 3, the net result will be a polarity inversion. If the entire signal path is unbalanced, including inputs and outputs (that being the case with the Metis), unless the component is one of the few designs which utilizes a coupling transformer somewhere in the signal path the inversion cannot be corrected by means of a wiring change, since there will be no point in the signal path where both polarities exist.
If the design is fully balanced, or if it provides balanced inputs or outputs, or if it has a coupling transformer in the signal path, it would be possible for the designer to compensate for an inversion by means of a wiring change.
Regards,
-- Al