Focusrite ISA 428 MkII Four Classic Microphone Preamp

Now in its second generation, the ISA 428 Mk II incorporates four of Focusrite's renowned mic pres in a simple-to-operate 2U enclosure, placing four mic preamps, instrument inputs and line ins at your fingertips. The original Focusrite mic pre was designed to suit the microphones of the time; today's model makes one small change, adding three additional input impedances to the classic ISA110 setting, allowing you to match any microphone, old or new, and access a wide range of sounds, from the character and warmth of a vintage mic to the clear transparency of a modern design. Or you can experiment and bring out just the qualities you want.In addition to the mic inputs, there are four front-panel instrument inputs making the ISA428 Mk II ideal for overdubs in the control room with no need for a DI box. On the back: four line inputs and switchable insert points on each channel to allow routing via external signal processors. There's also a versatile, vintage design variable high-pass filter to control what's going on at the bass end. And finally… accurate, 6-LED meters to tell you exactly what's going down. Optionally available for the ISA428 Mk II is a precision eight-channel A-D converter with 122dB dynamic range and superb jitter performance – ideal for simple interfacing with your DAW.
Key Features:

Four ISA series transformer-based preamps:

ISA series mic preamps have been the producers' choice on countless hit records over the last two decades.

Eight-channel optional A-D converter:

Four additional A-D converter inputs allow eight channels of high quality conversion, with a dynamic range of 122dB and jitter performance below 250 picoseconds.

Selectable impedance:

Ideal for mic matching or extended microphone creativity. Settings include the 'Vintage ISA110' setting, providing the original focusrite signature sound.

Four front panel instrument inputs:

Instant access on the front fascia - no separate DI box required.

Dedicated analogue insert points:

Switchable insert points are featured on every channel, allowing routing (between preamp and output) through additional external processing.

Accurate LED meters for every channel:

Clear metering designed to catch even the fastest and most elusive of transients.

Focusrite ISA 428 MkII Specifications:

Mic Inputs
Frequency response at minimum gain (0dB) (Mic): -0.35dB at 20Hz and –3dB at 122kHz
Frequency response at maximum gain (60dB) (Mic): –2.5dB at 20Hz and –3dB 103kHz
Gain range (Mic): 0dB to 60dB in 10dB steps, plus 0dB to 20dB continuously variable trim
Maximum headroom (Mic): 7.4dBu
Noise EIN (Mic): -126dB (measured at 60dB of gain with 150O termination and 20Hz/22kHz bandpass filter)
Noise at main output with unity gain (Mic): -98dBu (measured with a 20Hz/22kHz bandpass filter)
SNR (Mic): 123dB (relative to max output 25dBu) 120dB (relative to 0dBFS ( 22dBu)
CMRR (Mic): 88dB
Input Impedance, variable (Mic): 600O, 1400O, 2400O, 6800O

Line Inputs
Frequency Response at unity gain (0dB) (Line): -0.3dB at 20Hz and –3dB at 94kHz
Gain range (Line): -20dB to 10dB in 10dB steps, plus 0dB to 20dB continuously variable trim
Maximum headroom (Line): 25.4dBu
THD N (Line): 0.002 (measured with 4dBu input signal, 0dB gain setting, with a 20Hz/22kHz bandpass filter)
Noise at main output with unity gain (Line): -91dBu (measured with a 20Hz/22kHz bandpass filter)
SNR (Line): 116dB (relative to max output 25dBu) 113dB (relative to 0dBFS 22dBu). Input Impedance: 10kO
Frequency Response at 10dB gain (Instrument): -0.2dB at 20Hz and 0dB at 200kHz
Frequency Response at 40dB gain (Instrument): -3dB at 20Hz and –3dB at 38.4kHz

Instrument Inputs
Gain range (Instrument): 10dB to 40dB continuously variable
Maximum headroom (Instrument): 11.5dBu
Noise at main output with minimum gain ( 10dB) (Instrument): -95dBu (measured with a 20Hz/22kHz bandpass filter)
Input Impedance (Instrument): >1MO

High Pass Filter
Roll Off: 18dB per octave 3 pole filter
Frequency range: 16Hz to 420Hz (continuously variable, measured at the 3dB down point)

Front and Rear Connectivity
Analogue Audio Outputs (Outputs 1-4): 4 line XLR outputs on rear panel, 4 insert send 1/4" TRS jacks on rear panel
Other I/O: IEC power input connector 100Vac – 240Vac

Weight and Dimensions
Weight: 5.5kg (12.2lbs)
Dimensions: 480mm (W) x 88mm (H) x 280mm (D)
Dimensions: 18.8" (W) x 3.4" (H) x 11" (D)