Portable USB headphone amps

Specs as supplied by the manufacturer.

Cambridge DacMagic XS £99.95

 

Connections
Micro USB input, 3.5mm analogue output 
Digital to Analogue Converter
ESS9023 24-bit DAC 
Sample Rates Supported
USB 1.0 mode: 16/24-bit, 44.1kHz, 48kHz, 88.2kHz, 96kHz 
USB 2.0 mode: 16/24-bit, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz
Output Voltage 2V RMS
Max. Power Consumption
150mW 
Min. Headphone Impedance 12 Ohms
Frequency Response +/-0.2dB 20Hz – 20kHz
THD (unweighted): <0.004%
SNR
103 dBr (unweighted) 
Crosstalk 66dB
Output Impedance 0.5 Ohms
Volume Steps 53 steps (54 different volume levels) 
Dimensions (W x H x D):
30 x 10 x 53.5mm (1.2 x 0.4 x 2.1’’) 
Weight
100g (3.5oz)