Fi sound; and safe for your expensive headphones. Specifications Specifications Details Model P2 OP-Amp NE5532 Headphones Output 16-64Ohm Headphone Impedance 32-600 Ω Input Mode 3.5mm Audio jack, Stereo L / R RCA Frequency Range 20Hz-20 k - Hz (± 3d - B) THD ≤0, 03% SNR ≥ 95db ...Fi sound; and safe for your expensive headphones. Specifications Specifications Details Model P2 OP-Amp NE5532 Headphones Output 16-64Ohm Headphone Impedance 32-600 Ω Input Mode 3.5mm Audio jack, Stereo L / R RCA Frequency Range 20Hz-20 k - Hz (± 3d - B) THD ≤0, 03% SNR ≥ 95db Input Sensitivity 0.2m - V Device Dimension L99 * W98 * H33 mm Device Weight 0.25 kg Operating Voltage DC12V What‘s in the box? Item Quantity P2 Headphone Amplifier x 1 6J4 Vacuum Tubes x 2 DC 12V Power Supply x 1 6.35mm to 3.5mm Adapter x 1 User’s Manual x 1 Compare with similar items: P1 Pro Bluetooth 5.0 Tube Preamplifier P1 Vacuum Tube Pre-Amplifier