Quad PA-One+ Headphone Amplifier

Input Impedance: 50kΩ
Output Power: 500mW (@32Ω
Output Impedance: 32Ω～300Ω
Input Sensitivity: 300mV
Frequency Response: 20Hz～20kHz (+0dB,-0.5dB)
Distortion: 0.5 per cent at 1kHz
Channel Balance: ±0.5dB
S/N Ratio: 90dB
Vacuum Tubes: 2x 6SL7, 2x 6SN7
Digital Input Sampling Frequencies: 44.1kHz-192kHz, 384kHz(USB), DSD256 (USB)
Input Jack: 3-pin balance, 1xRCA, 1xUSB, 1xCOAX, 1xOPT
Output Jack: 1xstandard headphone jack, 4-pin balance headphone jack, 1xRCA output
Size: W/D/H – 180mm x 260mm x 170mm
Net Weight: 15.4 lbs.
Price: $1,695 USD
https://www.innerfidelity.com/content/quad-pa-one-headphone-amplifier-review-page-2