SPL HPm - 500 Series Headphone Monitoring Amplifier
SPL HPm - 500 Series Headphone Monitoring Amplifier
500 Series double-slot module headphone monitoring amplifier with Phonitor Matrix for two headphones.
The headphone output stage
The HPm delivers full headphone sound – twice! The output stage of the headphone amplifiers is designed as a push-pull amplifier in Class AB mode. The bipolar transistors share the amplification of the positive and negative half-waves, which produces a higher gain and a higher output voltage than in Class A operation, where only one transistor amplifies both half-waves.
The output stage transistors are thermally coupled and thus run particularly coherently, which contributes to a consistent and stable sound image. The power supply has a buffer circuit with low source resistance, ensuring generous current reserves even when operating low-impedance headphones. Both headphone amplifiers provide an individual volume control.
Stereo/Mono/Mute
The audio signal can be switched between stereo and mono. In the Mute position, the headphone outputs are muted.
Phase Inverse Ø
With the phase inversion switch the phase the of the left or right channel can be inverted (180°).
Crossfeed
The “Crossfeed” parameter of the HPm is continuously adjustable via the crossfeed control.
Speaker Angle
The “Angle” parameter can be adjusted in three settings: 20°, 30° and 40°. The studio standard is 30°.
Center Level
To make the listening experience even more perfect, the level of the center of the stereo image needs to be attenuated when the Phonitor Matrix is active. This ensures that not only the position of all sound sources is correct but also their volume. With HPm, this parameter, which we call “Center” in the Phonitor Matrix, can also be adjusted in three settings. You can choose between an attenuation of -0.5dB, -1 dB or -1.5 dB. The standard for an authentic representation of the stereo image is -1 dB. During conventional listening on headphones, our brain can compensate a certain level of false playback representation – but this is very exhausting and leads to listening fatigue.
SPL HPm Specifications
- Maximum input & output gain: 21 dBu
- Input impedance: 10 kΩ
- Output impedance: 150 Ω
- Common mode rejection: > 82 dB
- Frequency range (-3 dB): 10 Hz – 100 kHz
- THD & N (0 dBu, 10 Hz – 22 kHz): 0.03 %
- Noise (A-weighted): -92.3 dB
- Dynamic range: 113 dB
- Wiring: Tip = Left, Ring = Right, Sleeve = GND
- Max output power (600 Ω): +18 dBu
- Max output power (300 Ω): +15 dBu
- Max output power (32 Ω): +5 dBu
- Double-spaced module for 500 Series
- Unit weight: 0.8 kg/1.76 lbs
- Shipping weight (incl. packaging): 0.9 kg/1.98 lbs