The ISA 428 Pre Pack is the perfect multi-channel front end for any professional DAW.
Four classic Focusrite transformer-based pre amps with switchable impedance and direct
instrument inputs. An optional eight channel 192kHz ADC, preceded by the all new proprietory
Soft Limiter circuit, provides the perfect path into your Pro Tools HD system.
The benefits of the pre amp’s topology include superb common-mode rejection, an excellent
overload margin and, with its shared gain structure (20dB from the hand-wound transformer and
up to 40dB from the amplifier), an extremely low noise floor and super-wide bandwidth (10Hz to
200kHz). This pre amp design is the cornerstone of Focusrite’s signature ‘warm-yet-transparent’
sound and is a point of reference for any discerning audio professional.
In addition, the input stage provides enhanced control and creativity allowing you to switch between
four carefully selected input impedance settings. The original ISA 110 setting is supplemented by
three further impedance settings to either perfectly match the pre amp with any microphone and
maximise level, or use different settings creatively to shape the sound of the microphone being used.
Should the need arise to place extra processing in between pre amp and conversion, insert points are
also featured on every channel.
Protecting the ADC, the Soft Limiter opto circuit is a new design from Focusrite, entirely preventing any
‘digital overs’, whilst minimising the undesirable distortion that standard limiter circuits often generate.
Finally, the new ADC embodies cutting-edge conversion technology, encompassed within pristine Focusrite
circuitry, providing eight conversion channels of the highest quality, at frequency rates of up to 192kHz.
Running at 96kHz allows for up to 16 (2 x 8, parallel) simultaneous digital outputs in addition to the four
main analogue outputs. Digital output options include dual AES/EBU, SPDIF and dual ADAT lightpipe.
Full digital metering is provided for every channel, alongside new ‘moving coil’ peak meters, designed to
catch even the fastest of transients.
A second analogue unit can be connected utilising the four extra ADC input channels on the rear of the unit
containing the optional ADC. This makes full use of the eight channels provided on a single optional ADC and
expands your front-end capacity from four pre amps and eight digital outputs to eight Pre amps and eight digital
Classic preamp technology, custom Focusrite input and limiting circuits and the very best in A/D conversion
technology, the ISA 428 Pre Pack raises the bar for multi-channel recording solutions into Pro Tools HD, or any
other professional DAW. Equally, it can be used as an additional set of high quality pre amps for any analogue
or digital console or hard disk recorder.
Four classic Focusrite transformer-based preamps.
8 channels of cutting-edge A/D conversion, running at up to 192kHz. Protected by proprietory optical Soft Limiter
Switchable Impedance for unparalleled mic matching or extended mic creativity – includes the classic ISA 110
Multiple Front Panel Instrument DI. No separate DI box required.
Analogue insert points on every channel.
High Pass Filters on every channel.
New moving coil peak meters & full digital metering (dBfs).
ADAT is a trademark of Alesis Corp
Pro Tools HD is a trademark of Avid Technologies plc.
The 192kHz ADC is an extra cost option.
Transformer-based ISA design
Gain range: Line = +/- 18dB, Mic = 0 to 60dB (both in 6dB steps), Inst = +10 to +40 dB
Input impedance: Line = 10k ohm, Mic = Variable – 600, 2k4 and 6k8 ohm + original ISA 110
settings, Inst = >1M ohm
Noise: Line = -96dB, Mic = -128dB (EIN with 150 ohm input resistance at 60dB of gain)
THD: Line = 0.003% with 0dBu, 1kHz input and 20Hz to 22kHz band-pass filter, Mic = 0.003%
Analogue Input and Output connectors (balanced)
D.I inputs: 1/4 inch Jack (unbalanced)
Mic inputs: XLR (balanced)
Line: TRS Jack (balanced)
Insert Sends and Returns: TRS Jack (balanced)
Additional ADC inputs: XLR (balanced) Line level
Analogue Outputs: XLR (balanced)
Digital Output Option
AES/EBU and S/PDIF dual 9-pin D-types
Optical – ADAT Lightpipe
Bit depths 16-, 20- or 24-bit
Frequency options 44.1, 48, 88.2, 96, 176.4 and 192kHz
Clock options Standard or ?256 x?
Meter – 0 dBFS = +22dBu
SNR – 120dB A-weighted