Focusrite ISA428 MkII 4-Channel Mic Preamp

Focusrite ISA428 MkII 4-Channel Mic Preamp - Four classicpreamps with DI inputs and a premium eight channel A-D converteroption. ISA series mic preamps have been the producers’ choice oncountless hit records over the last two decades.

The ISA428 mk2 provides four of Focusrite’s prestigioustransformer-based microphone preamps. It features the same classiccircuitry and renowned audio quality found in the original at a newlevel of affordability. With selectable input impedance, directinstrument inputs and an optional eight channels of high-qualityanalogue to digital conversion, the ISA428 MkII creates the perfectfront end for the discerning recording professional.

The Focusrite ISA 428 Mark II features four additional A-Dconverter inputs allow eight channels of high-quality conversion,with a dynamic range of 122dB and jitter performance below 250picoseconds.

Ideal for mic matching or extended microphone creativity.Settings include the ‘Vintage ISA110’ setting, providing theoriginal Focusrite signature sound.

Focusrite ISA428 MkII 4-Channel Mic Preamp MainFeatures:

• Four ISA-series transformer-based pre-amps
  • Over the past three decades, ISA mic preamps have contributedto many of the world’s most significant albums.
• Eight Channel optional A/D converter with 122dB dynamic range.
  • The same cutting-edge analogue to digital converter card usedin the ISA828. Four additional ADC inputs allow eight channels ofhigh quality conversion.
• Switchable Impedance
  • Ideal for mic matching or extended microphone creativity.Settings include the 'Vintage ISA110' setting, providing theoriginal Focusrite signature sound.
• Four front panel instrument inputs
  • Instant access on the front fascia - no separate DI boxrequired.
• Dedicated analogue insert points
  • Switchable insert points are featured on every channel,allowing routing (between pre-amp and output) to additionalexternal processing.
• Variable high pass Focusrite filter
  • Provided on every channel, this is the same filter as featuredon the original ISA110 and the legendary Focusrite forteconsole.
• Accurate LED meters for every channel
  • Clear metering designed to catch even the fastest and mostelusive of transients.
• Weight: 5.5kg (12.2lbs)
• Dimensions (W x H x D): 480mm (W) x 88mm (H) x 280mm (D) / 19"(W) x 3.5" (H) x 11" (D)

Focusrite ISA428 MKII 4-Channel Mic Preamp 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 +20dBcontinuously variable trim
  • Maximum headroom: +7.4dBu
  • THD+N: 0.0009% (measured at 1kHz -20dBu input signal, at 30dBgain setting, with a 20Hz/22kHz bandpass filter)
  • Noise EIN: -126dB (measured at 60dB of gain with 150 ohmtermination and 20Hz/22kHz bandpass filter)
  • Noise at main output with unity gain: -98dBu (measured with a20Hz/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 : Equivalent Input Impedance at1kHz
    • Low : 600 ohms
    • ISA110 : 1400 ohms
    • Med (Medium) : 2400 ohms
    • High : 6800 ohms
• Line Inputs
  • Frequency Response at unity gain (0dB): -0.3dB at 20Hz and -3dBat 94kHz
  • Gain range: -20dB to +10dB in 10dB steps, plus 0dB to +20dBcontinuously variable trim
  • Maximum headroom: +25.4dBu
  • THD+N: 0.002% (measured with +4dBu input signal, 0dB gainsetting, with a 20Hz/22kHz bandpass filter)
  • Noise at main output with unity gain: -91dBu (measured with a20Hz/22kHz bandpass filter)
  • SNR: 116dB (relative to max output 25dBu)
  • SNR: 113dB (relative to 0dBFS +22dBu). Input Impedance: 10kohms
• Instrument Inputs
  • Frequency Response at +10dB gain: -0.2dB at 20Hz and 0dB at200kHz
  • Frequency Response at +40dB gain: -3dB at 20Hz and -3dB at38.4kHz
  • Gain range: +10dB to +40dB continuously variable
  • Maximum headroom: +11.5dBu
  • THD+N: 0.006% (measured with -20dBu input signal, at minimumgain (+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 = >1M ohm
• High Pass Filter
  • Roll off = 18dB per octave 3 pole filter
  • Frequency range: 16Hz to 420Hz (continuously variable, measuredat the 3dB down point)
• Meters
  • 6 LED meter is calibrated 0dBFS = +22dBu (the maximum levelwhich can be correctly converted by the optional internal A/Dconverter before overload occurs). The meter calibration points areas follows:
    • Meter panel calibration value in dBFS : Equivalent dBuvalue
    • 0dBFS : +22dBu
    • -2dBFS : +20dBu
    • -6dBFS : +16dBu
    • -12dBFS : +10dBu
    • -18dBFS : +4dBu
    • -42dBFS: -20dBu

  Focusrite ISA428 MKII 4-Channel Mic Preamp - Front and RearConnectivity

  • 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)