Product Overview
The Focusrite ISA428 MkII provides four of Focusrite’s prestigious transformer-based microphone preamps. It features the same classic circuitry and renowned audio quality found in the original at a new level of affordability.
And now you can add the iconic sound, feel, and styling of the legendary Focusrite console to your production toolkit simply by registering your ISA428 MKII. The Bx_console Focusrite SC is a virtual channel strip from the original console featuring the ISA 110 EQ and ISA 130 dynamics module including the compressor/limiter, expander/gate, and de-esser. The plugin is an SC VST/AU/AAX compatible plug-in for Mac and PC, and yours for free upon registration, a $349 value!
With selectable input impedance, direct instrument inputs, and an optional eight channels of high-quality analog-to-digital conversion, the ISA428 MkII creates the perfect front end for the discerning recording professional.
First introduced in 1985, the ISA microphone preamp holds a reputation for outstanding transparency along with subtle warmth contributed by transformer core saturation. The addition of a variable impedance circuit allows ISA users to perfectly match the preamp with any microphone, or to use different settings creatively to shape the sound of the microphone. Unchanged for decades, the ISA microphone preamp topology offers incredible clarity and the signature Focusrite sound that makes it the top choice among many audio professionals today.
Features
- Four ISA Series Transformer-Based Preamps
- Eight-Channel Optional A-D Converter
- Selectable Impedance
- Four Front Panel Instrument Inputs
- Dedicated Analogue Insert Points
- Variable High-Pass Focusrite Filter
- Accurate LED Meters for Every Channel
Specifications
- Mic Inputs:
- Frequency response @ minimum gain (0dB): -0.35dB at 20Hz and –3dB at 122kHz
- Frequency response @ 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 @ 1kHz -20dBu input signal, @ 30dB gain setting, with a 20Hz - 22kHz bandpass filter)
- Noise EIN: -126dB (measured @ 60dB of gain with 150Ω termination and 20Hz - 22kHz bandpass filter)
- Noise @ 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: 600Ω, 1400Ω, 2400Ωs, 6800Ω
- Line Inputs:
- Frequency Response @ unity gain (0dB): -0.3dB @ 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 @ 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 @ +10dB gain: -0.2dB @ 20Hz and 0dB @ 200kHz
- Frequency Response @ +40dB gain: -3dB @ 20Hz and –3dB @ 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 @ main output with minimum gain (+10dB): -95dBu (measured with a 20Hz - 22kHz bandpass filter)
- Input Impedance = >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)
- Meters:
- Meter panel calibration value in dBFS / Equivalent dBu value:
- 0dBFS / +22dBu
- -2dBFS / +20dBu
- -6dBFS / +16dBu
- -12dBFS / +10dBu
- -18dBFS / +4dBu
- -42dBFS / -20dBu
- 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:
- Front and rear connectivity:
- Analogue Channel Inputs (Inputs 1-4):
- 4 instrument 1/4” TS jack inputs on front panel
- 4 microphone XLR inputs on rear panel
- 4 line 1/4” TRS jacks on rear panel
- 4 insert return 1/4” TRS jacks on rear panel
- 4 ADC XLR inputs on rear panel
- 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
- Front Panel Indicators:
- 8 output meters, 6 segment
- 4 30-60 mic gain range selection indicator
- 4 +48V phantom power indicator
- 4 Phase indicator
- 4 Insert In indicator
- 4 Filter In indicator
- 4 Input selection indicators (Mic, Line, Inst)
- 4 Z In microphone input impedance selection indicators (Low, ISA110, Med, High) Clock select indicators (44.1, 48, 88.2, 96, 176.4, 192)
- Ext clock indicators (Lock, Word clock, 256X)
- Weight: 12.2lbs (5.5kg)
- Dimensions (WxHxD): 19" x 3.5" x 11" (80 x 88 x 280mm)
