ISA 428 MKII
Four Classic Mic PresProduct Highlights
- Classic ISA mic preamp design featuring Lundahl LL1538 input transformer
- Instrument and line inputs with dedicated input connectors and front-panel switch
- Switchable input impedance including classic ISA 110 setting
- Variable cut-off frequency high-pass filter
- Dedicated switchable insert point
- Per-channel six-segment LED peak-level meters
- Optional A-D card with up to 192kHz, 24-bit sampling via ADAT or AES3
- Overview
- Tech Specs
Four Classic Mic Pres
ISA 428 MkII 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 ISA 110 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.
Each mic pre has the option of mic, line or the front-panel instrument input, with variable input impedance to ensure you are getting the best performance from the source. Up to 60dB of gain is available on the four-position rotary and gain range switches, with a further +20dB of continuously variable trim, meaning a huge 80dB of gain is available should it be required. The high-pass filter features variable cut-off frequency between 16 and 420Hz. An array of 6-segment LED meters show peak signal level for the four mic pres, in addition to the four direct inputs to the optional A-D card. Switchable rear-panel insert points allow the use of inline processors such as compression.
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) |
WEIGHT AND DIMENSIONS
- Weight: 5.5kg (12.2lbs)
- Dimensions: 480mm (W) x 88mm (H) x 280mm (D)