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.

3 Stereo Inputps
Two analog stereo inputs and one digital USB input can be connectedpd TRS jacks or unbalanced RCA connections.

32-Bit DA-Converter
The converter chip used is the pt a noticeable drop in quality. You can also record the signal analog or send it to a mixer for further processing. Because of this line output, you can use the Phonitor One d as a high-quality DAC, as well as a headphone amp.

Comprehensive Preamp Stage
Two Burr-Brown OPA 2134 SoundPlus operational amplifiers provide the pre-amplification. These are specially designed for audiophile circuits and are characterized by low noise and minimal distortion of 0.00008%. Thanks to a true FET stage, the OPA 2134 achieves a slew rate of 20V/µs.