Optional audio transformers
Lundahl is the renowned Swedish manufacturer of excellent audio transformers, which can be optionally installed in appropriately prepared SPL devices.
Transformers can be used as an alternative to electronic balancing stages in the inputs and outputs.
The bass and fundamental range becomes rounder, fuller and gets more pressure, the high and overtone range sounds a bit silkier and more present.
Reasons are reduced portions of odd harmonics (which are responsible for hard high tone) and a certain inertia compared to electronic stages, which leads to the more voluminous low tone characteristics.
However, electronic stages are better for highest precision and speed in signal transmission (transients).
The bottom line: it’s a question of taste and application.
When equipped with input and output transformers and completely symmetrical cabling, no voltages can enter the device via the signal connections that could cause damage.
The signal transmission is inductive and thus electrically isolated.
No hum is guaranteed. And last but not least, transformers drive very long cable runs, which is a welcome feature in live applications at the latest.