The Phonitor One d From SPL is a headphone amplifier that offers an audiophile-grade performance to listeners and professionals alike. Because of its pristine preamp, powerful headphone amplifier, and ability to handle high-quality PCM/DoP, the unit is suitable for those who enjoy high-quality critical listening, such as the audiophile, who might spin a record to unwind at the end of the day. However, because of its 32-bit DAC and dedicated stereo line outputs, the unit is also beneficial to professional engineers who need a high-quality monitoring path.
Whoever you are, you can make connections to the unit via balanced 1/4", unbalanced RCA, or USB connections. An input selector lets you switch among the three sources, and you'll also note the Crossfeed knob. This engages the Phonitor Matrix, SPL's technology for emulating speaker positioning within a room, all in your headphones. With the Crossfeed knob, you can dial in subtle amounts of the opposing channel to emulate the feeling of speakers. Mixing engineers might find this feature particularly handy when mixing in headphones.
The headphone amp itself utilizes a Class AB design, and is able to power both high- and low-impedance headphones alike. You can go between your favorite consumer-grade closed-back headphones and your high-grade open-backs without a problem. A 12V external power supply unit is included.
Additionally, low capacitance film capacitors are installed in the signal path as bypass capacitors of the coupling capacitors, which ensures a more precise transmission of the high-frequency signal components. Finally, the Panasonic 'Electric Double Layer' gold electrolytic capacitors are used as coupling capacitors.
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.
At the beginning of the control path the function is not in the audio path. It is only switched on by adding it via relay (hysteresis circuit). The audio signal therefore does not pass through the crossfeed stage if this is not desired.