We always quote 'real world' performance figures (measured to the AES17 standard). Some companies choose to quote chipset performance, which is misleading, and . Microphone Inputs Dynamic Range (A-Weighted): 109dBSNR (A-weighted): -109dBFrequency Response: 20Hz - 20kHz +/- 0.1 dBTHD+N: 0.001% (measured at 1kHz with a 20Hz/22kHz bandpass filter)Noise: EIN > 125dB (128dB analogue to digital) (measured at 60dB of gain with 150 Ohm termination (20Hz/22kHz bandpass filter)Maximum level (A-weighted): 8dBu at 1%Line Inputs Dynamic Range (A-Weighted): 109dBSNR (A-weighted): -109dBFrequency Response: 20Hz - 20kHz +/- 0.1dBTHD+N: < 0.001% (measured with 0dBFS input and 22Hz/22kHz bandpass filter)Noise: -90dBu (22Hz/22kHz bandpass filter)Maximum level (A-weighted): 28.5dBu at 1%Instrument Inputs Frequency Response 20Hz-20KHz +/- 0.1dBMaximum Input Level min gain no pad +8dBuMaximum Input Level max gain no pad -42dBuTHD+N, -1dBFS, min gain, no pad < 0.0015%SNR 109dB "A"DNR 109dB "A"Input Impedance > 1MOhmX-talk < -100dBAdjustable Gain > 50dBPad Attenuation 10dBHeadphone Outputs Frequency Response 20Hz-20KHz +/- 0.1dBSNR 109dB "A"DNR 109dB "A"Maximum Output into 32R +12.4dBu (+10.2dBV)Power into 32R 250mWOutput Impedance < 7OhmsLoad Impedance > 24OhmsLine level Outputs Dynamic Range (A-Weighted): 108dBSNR (A-weighted): -108dBTHD+N: < 0.001% (measured with 0dBFS input and 22Hz/22kHz bandpass filter)Maximum level (A-weighted): 15.7dBu at 0.883%Additional Conversion Performance Clock jitter < 250 picosecondsTHD+N AMPL (A-weighted)= -109dBFSConnectivity Analogue Channel Inputs (Inputs 1-8) Mic inputs 1-8 on rear XLR’s. Line inputs 1-8 on rear 1/4” TRS. Instrument inputs on channels 3 and 4 (separate front panel 1/4” TRS). Notes Individual switchable High Pass Filter on all inputs.Phase switch on inputs 3, 5 and 7. Input Pad on inputs 3 and 4 = -10dB.Analogue Outputs Line level 10 x 1/4” TRS Jack.Notes Outputs Monitor 1 and 2 have anti-thump protection circuitry.Digital I/O SPDIF input and output (RCA phono) on rear panel, (24-bit, 44.1 - 192kHz),  output transformer isolated.Optional AES output mode with professional channel status and voltage levels on SPDIF output.2 x ADAT In / Out 16 channels (44.1 / 48kHz), 8 channels S-MUX (88.2 / 96kHz), 4 channels S-MUXII (176.4 / 192kHz).ADAT Input and Output 2 can be re-configured to be optical SPDIF input / output via control panel.BNC Word clock input and output (75 ohms).MIDI I/O 1 in / 1 out (16 channels) on rear panel.Headphone monitoring 2 x 1/4” TRS Jack on front panel (mirrors outputs 7-8 and 9-10). NOTE: These are high power headphone drivers.Other I/O 2 x 6 pin FireWire 400 socket - also compatible with FireWire 800 and Thunderbolt2 Standard 5-pin DIN MIDI connectors: In and OutIEC mains power input connectorWeight and Dims 5kg / 11 Ibs480mm / 19" (W) x 90mm / 3.6" (H) x 235mm /9.3" (D)