The Atoll HD120 digital-to-analog converter uses the PCM5102 chip, providing signal processing accuracy up to 32-bit / 384 kHz. The device has an asynchronous USB input, through which it is capable of receiving a stream with parameters up to 24 bit / 192 kHz, as well as optical and coaxial. The digital input block is made on a separate board, which provides good protection against crosstalk. The device can also receive signals via Bluetooth from compatible portable devices. The output impedance of the headphone amplifier is 1 ohm, which ensures good compatibility with models with different impedances.
The Atoll HD120 metal case contains a preamplifier for two analog signal sources, a digital-to-analog converter and a headphone amplifier. The device is manufactured using selected components, and its design takes into account all the nuances that may affect the sound quality.
In the middle of the 4mm thick aluminum front panel is a volume control, to the left of which is a row of LEDs to indicate the selected input, and to the right are two headphone jacks and source switching buttons. The Atoll HD120 power supply contains three network transformers optimized for use in audio equipment, as well as eight stabilized voltage sources, individual for each functional unit.
The power of the power supply is 12.8 VA, and the total capacitance of the filter capacitors is 12425 μF. The preamplifier volume control is based on an Alps motorized potentiometer, which makes it possible to implement remote control of the signal level without degrading sound quality. The output stages of the preamplifier operating in class A are made using field-effect transistors. The analog circuit is made on discrete elements, it uses metal-film resistors and audiophile-grade MKP capacitors.
Characteristics of Atoll HD120
Inputs 2 linear, USB asynchronous, optical, coaxial
Outputs RCA preamplifier, for 2 pairs of headphones
Additionally Bluetooth, 12-volt trigger output
DAC PCM5102, 32 bit / 384 kHz
Frequency range 1 Hz – 150 kHz
Signal-to-noise ratio 112 dB
Harmonic distortion less than 0.01%
Output slew rate 3 µs
Headphone amplifier output impedance 1 ohm Headphone
amplifier output power 1.4 W (32 ohms)
Filter capacitor capacity 12425 µF
Power supply power 12.8 VA
Dimensions (WxHxD) 320 x 60 x 220 mm
Weight 2.5 kg
