HPm is a modular headphone amplifier and the first 500-series module to feature SPL’s  hugely popular Phonitor Matrix technology.

Two For One

In just a single dual-slot module, HPm can power two independent headphone outputs each from their own separate amplifiers. This allows for no-compromise quality SPL-standard headphone amplification as well as independent control for both channels.

Into The Matrix

Inherited from their flagship Phonitor headphone amplifier, Phonitor Matrix is a unique proprietary SPL technology which eliminates the “super stereo” effect caused by normal headphone listening.

Through a unique system of crossfading, Phonitor Matrix can emulate the effect of listening to angled speakers and filling in the mix gaps that regular hard-left and hard-right channels miss. This allows for much more translatable mixing between headphones and studio monitors both in and out of the studio.

HPm can be easily situated between DAWs and monitor controllers without disruption mixing workflow and phase inversion, stereo to mono, and mute are all switchable on the fly.

Main Features

  • Dual output headphone amplifier 
  • Separate amplifiers for each output
  • Built-in Phonitor Matrix functionality
  • Adjustable speaker angle crossfeed control
  • Independent headphone channel controls
  • Stereo/Mono switchable
  • Phase reverse control
  • Designed for 500-series racks and lunchboxes


Max Input Level:
+21 dBu
Max Output Level:
+18 dBu @ 600 Ohm; +15 dBu @ 300 Ohm
Frequency Range:
10Hz -100kHz
-92.3 dBu (A-weighted)
0.00024% @ 0 dBu output, 600Ohms

Physical Properties

Dual-Slot 500 series
0.8 kg

Authorised Retail Partners

Funky Junk
SX Pro
SSP (inc VAT) £ 319.00
EAN 4260149321701