Is there an installation direction or polarity for transformers?

With transformers, there is no “direction” as with polarized components, but there is a primary and a secondary side. The correct connection depends on the desired signal flow and the circuit (balanced / unbalanced). In addition, the phase position is important. Please always refer to the datasheet!

Tip:

If whistling or loud oscillation occurs after installing the output transformer, it is usually wired with reversed polarity.

Measure the frequency response. In some cases, it may be advisable to reverse the transformer polarity on both the primary and secondary side in order to achieve an improvement.