... 16-64Ω4. harmonic distortion: THD + N: <0.001%5. signal to noise ratio: 105dB6. Channel separation: 102dB7. Power ... protection circuit.2.independent professional circuit design, cost-effective portable headphone amplifier, perfect sound quality.3.TI, HIFI level by the ... ,matching left and right balance, ensure the sound quality.5.Japan famous ELNA (purple) audio professional electrolytic capacitors, ...