SPL Audio Phonitor One Headphone Amplifier

About: SPL Audio Phonitor One Headphone Amplifier

SPL Phonitor One w/ DAC - The Audiophile Headphone Amplifier

Two Burr-Brown OPA 2134 SoundPlusTM operational amplifiers provide the pre-amplification. These are specially designed for audiophile circuits and are characterized by extremely low noise and minimal distortion of only 0.00008%.

Thanks to a true FET stage, the OPA 2134 achieves a slew rate of 20V/μs, making it a high-speed operational amplifier. This has an immediate positive effect on the liveliness of the playback.

In addition, 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.

The excellent Panasonic ‘Electric Double Layer’ gold electrolytic capacitors are used as coupling capacitors.

The Power Amplifier

Two Burr-Brown OPA 2134 SoundPlusTM operational amplifiers provide the pre-amplification. These are specially designed for audiophile circuits and are characterized by extremely low noise and minimal distortion of only 0.00008%.

Thanks to a true FET stage, the OPA 2134 achieves a slew rate of 20V/μs, making it a high-speed operational amplifier. This has an immediate positive effect on the liveliness of the playback.

In addition, 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.

The excellent Panasonic ‘Electric Double Layer’ gold electrolytic capacitors are used as coupling capacitors.

The output stage of the headphone amplifier is designed as a push-pull amplifier in class AB mode. 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.

The Revolution

The revolution in the headphone amplifier is the Phonitor Matrix – mixes made on headphones sound as they were mixed on speakers. The Phonitor Matrix in its largest expansion stage has three setting parameters: Crossfeed, Speaker Angle and Center Level.

In the Phonitor One, the center level is preset to -1 dB and the speaker angle to 30°. These are the most commonly used values. The crossfeed function determines the crosstalk of the channels, the so-called interaural level difference. The intensity of the crossfeed is fully variable. When the Crossfeed control is in the OFF-position the Phonitor Matrix is switched off – it is removed out off the audio signal path via relay (hysteresis circuit).