Model 37 Limiter (In-Phase)

The Model 37 In-Phase Limiter is a single polarity power supply Logic Module covered by an MU metal can with an Octal plug-in.

A Limiter is a circuit that allows signals below a specified input power to pass unaffected while attenuating the peaks of stronger signals that exceed this input power. Mastering engineers often use limiting combined with make-up gain to increase the perceived loudness of an audio recording during the audio mastering process.