Specifications; Mic Inputs; Line Inputs; Instrument Inputs - Focusrite ISA428 MkII Mode D'emploi

Specifications

Mic inputs

• Frequency response at minimum gain (0dB): -0.35dB at 20Hz and –3dB at 122kHz.
• Frequency response at maximum gain (60dB): –2.5dB at 20Hz and –3dB 103kHz.
• Gain range: 0dB to +60dB in 10dB steps, plus 0dB to +20dB continuously variable trim.
• Maximum headroom: +7.4dBu.
• THD+N: 0.0009% (measured at 1kHz -20dBu input signal, at 30dB gain setting, with a 20Hz/22kHz bandpass filter).
• Noise EIN: -126dB (measured at 60dB of gain with 150Ω termination and 20Hz/22kHz bandpass filter).
• Noise at main output with unity gain: -98dBu (measured with a 20Hz/22kHz bandpass filter).
• SNR: 123dB (relative to max output 25dBu).
• SNR: 120dB (relative to 0dBFS (+22dBu).
• CMRR: 88dB.
• Input impedance, variable as follows:
Switched impedance setting
Low
ISA110
Med (Medium)
High

Line inputs

• Frequency response at unity gain (0dB): -0.3dB at 20Hz and –3dB at 94kHz.
• Gain range: -20dB to +10dB in 10dB steps, plus 0dB to +20dB continuously variable trim.
• Maximum headroom: +25.4dBu.
• THD+N: 0.002% (measured with +4dBu input signal, 0dB gain setting, with a 20Hz/22kHz bandpass filter).
• Noise at main output with unity gain: -91dBu (measured with a 20Hz/22kHz bandpass filter).
• SNR: 116dB (relative to max output 25dBu).
• SNR: 113dB (relative to 0dBFS +22dBu).
• Input Impedance: 10kΩ.

Instrument inputs

• Frequency response at +10dB gain: -0.2dB at 20Hz and 0dB at 200kHz.
• Frequency response at +40dB gain: -3dB at 20Hz and –3dB at 38.4kHz.
• Gain range: +10dB to +40dB continuously variable.
• Maximum headroom: +11.5dBu.
• THD+N: 0.006% (measured with –20dBu input signal, at minimum gain (+10dB), with a 20Hz/22kHz bandpass filter).
• Noise at main output with minimum gain (+10dB): -95dBu (measured with a 20Hz/22kHz bandpass filter).
Input Impedance >1MΩ.
•

High pass filter

• Roll off = 18dB per octave 3 pole filter.
• Frequency range: 16Hz to 420Hz (continuously variable, measured at the 3dB down point).

Meters

• 6 LED meter is calibrated 0dBFS = +22dBu (the maximum level which can be correctly converted by the optional internal
A/D converter before overload occurs). The meter calibration points are as follows:
Meter panel calibration value in dBFS
0dBFS
-2dBFS
-6dBFS
-12dBFS
-18dBFS
-42dBFS
Equivalent input impedance at 1kHz
600Ω
1400Ω
2400Ω
6800Ω
Equivalent dBu value
+22dBu
+20dBu
+16dBu
+10dBu
+4dBu
-20dBu
15