ISA 430 MkII

ISA 430 MkII

The Focusrite Heritage Sound – in a complete channel strip

Focusrite’s ISA range is based around the original ‘no compromise’ designs that recording console design legend Rupert Neve built for Sir George Martin back in the mid-1980s, and every unit delivers the sought-after Focusrite Heritage Sound that lies behind thousands of top class recordings made over the intervening years in the world’s leading studios. With the ISA Range, you can put that sound at the heart of your own work – and the ISA 430 Mk II is the most sophisticated of them all: a complete channel strip in which every element can be used independently or patched in virtually any order – including a classic mic pre, versatile EQ, VCA/optical compressor, expander/gate and de-esser.

The original mic pre – with just a little more

Inside the 2U rack-mount enclosure, the ISA 430 Mk II features a Lundahl transformer-input microphone preamplifier and equaliser based closely on the original ISA 110, itself based on the design for the A7971 console by Rupert Neve, incorporating suggestions from George Martin and engineer Geoff Emerick. Virtually all we’ve changed is to give the mic pre a variable input impedance to get the best out of any microphone, modern or vintage, accurately or for effect. There’s also a special “air” button that opens out the sound without EQ.

Heritage equaliser with extra flexibility

The equaliser itself features two separate parametric bands plus shelving low and high frequencies, high- and low-pass filters and the ability to switch individual EQ elements into the compressor side-chain for frequency-conscious compression, gate keying and other effects. Indeed, the four powerful processors that make up the ISA 430 MkII can all be used independently or patched into each other in a variety of ways for maximum versatility.

Dynamics section combines heritage and modern technology

The dynamics section, once again, recalls the original Trevor Stride/Rupert Neve ISA 130 that dates back to 1987. It features a sophisticated expander/gate section as well as a versatile compressor, both featuring modern transparent VCA-based control elements for maximum compression without artefacts. But in addition, the compressor also features the original vintage optical design for a truly traditional sound, and you can also mix the original signal into the compressor output, maintaining dynamics as you take control. Like the other sections of the ISA 430 Mk II, there’s a “Listen” button so you can hear exactly what each module is doing.

Precision 24-bit A/D conversion

The ISA 430 Mk II is supplied with analogue outputs for full integration into a traditional audio path. But it’s as perfect a front-end for a digital system as an analogue one, and with that in mind we’ve created an optional class-leading high-precision 192kHz, 24-bit 2-channel A-D card boasting 120dB dynamic range, that slots straight into the unit. Like the other sections of the ISA 430 Mk II, it can be used as part of the overall channel strip or employed independently.

Four powerful processors – together or independent

Not only is the ISA 430 Mk II a powerful channel strip, combining heritage mic amps, equalisation and dynamics; and optional superb-quality digital conversion, each element (and in the case of the equaliser, each section) can be used as a completely separate device for the ultimate in versatility. The ISA 430 Mk II from Focusrite. It could be the last channel strip you’ll ever need.

Key Features

The Most Versatile Channel Strip

The ISA 430 MkII features Focusrite's ultimate heritage sonic signature including transformer-based mic pre, versatile EQ with two dual-range parametrics, compressor with both transparent VCA and vintage optical circuitry, expander/gate, phase-cancellation de-esser and optional 192kHz/24-bit 2-channel AD conversion.

Full Control Over Dynamics

The mic pre suits almost all mics including vintage and 'difficult' models such as ribbons. Variable impedance can be set for transparency or to highlight special features of the mic, such as presence bumps and rolloffs. Switchable additional inductance adds "air" without EQ.

Four Units in One, Independently Accessible

Use the mic pre, EQ, Dynamics and A-D converter independently, or route them to build powerful simultaneous processors. Re-order different sections to create multiple alternative signal paths.

Powerful Processing Options

Insert HPF, LPF and EQ into the Dynamics sections for frequency-sensitive processing - Listen function lets you audition the side-chain to fine-tune the effect.

Control Over Dynamics

Expander/gate features "hysteresis" setting to avoid chattering on difficult signals. De-esser is based on phase cancellation at the chosen frequency, for more natural sound.

Lundahl LL1538 Input transformer

The original mic transformers used in the original Red modules help to provide the unique sound and performance of this groundbreaking design.

Backlit VU Meter with Variable Calibration

ISA 430MkII has a moving coil VU meter with variable calibration to suit analogue and digital recording media, alongside two six-LED peak meters; inputs can be metered either pre- or post-insert.

ISA 430 MkII Specifications

Line

Gain Range +10dB to +40dB continuously variable
Input Impedance >1M Ohm

Mic

Gain Range 0 to +60dB in 10dB steps
Input Impedance Variable as follows: 600 Ohm, 1k4 Ohm, 2k4 Ohm, 6k8 Ohm
EIN -128dB with 150 Ohm terminating impedance at 60dB of gain
Noise -97dBu
THD 0.001% with -20dBu 1kHz input and 20Hz-22kHz bandpass filter

Compressor (VCA mode)

Threshold Range -28dB to +12dB
Ratio 1.5:1 to 10:1
Slope Soft knee
Attack 100µs to 100ms
Release 100ms to 7s, variable or auto (program dependent)

Compressor (Vintage Opto mode)

Threshold Range -28dB to +12dB
Slope Soft knee in Comp mode, Hard knee in Lim mode
Attack Fixed
Release Fixed

EQ

Low Pass Filter 18dB/oct from 400Hz to 22kHz
Parametric Section Comprised of low-mid & Hi-mid parametric, each with continuously variable boost/cut with centre detent, frequency sweep control with two ranges, and fully variable Q. Low-mid frequencies 40Hz to 400Hz (120Hz to 1k2Hz when x3 is pressed). Hi-mid frequencies 600Hz to 6kHz (1k8Hz to 18kHz when x3 is pressed
Shelving section Comprised of: high frequency shelf, with frequency range steps of 1.5kHz, 3.3kHz, 6.8kHz and 15kHz (2.2kHz, 4.7kHz, 10kHz and 18kHz when Hi Range is engaged), and low frequency shelf, with frequency range steps of 20Hz, 56Hz, 160Hz and 460Hz (33Hz, 95Hz, 270Hz and 655Hz when Hi Range switch is engaged)

Gate

Threshold Range -40dB to +10dB
Gate Range 0 to -80dB
Attack switched fast or slow
Release 100ms to 5s
Hold 20ms to 4s
Expander Ratio 0 to 5:1

De-Esser

Threshold Range 22dB
Frequency Range 2k2 to 9k2
Ratio at centre frequency 2:1

Limiter

Threshold Range 20dB
Ratio Infinite (Brick Wall)
Attack Frequency Dependent

Weight

7.58kg 16.7lbs

Dimensions

484mm (W) x 85mm (H) x 250mm (D) 19" (W) x 3.5" (H) x 9.8" (D)

Optional A-D Converter Specs

Output formats (All channels)

AES/EBU (5V / 110 ohms), S/PDIF (0.8V / 75 ohms)
ADAT lightpipe (SMUX I/II/IV)
S/PDIF lightpipe

Bit depth

24 bits

AES3 output jitter

<:500ps, 50Hz-100kHz
<:400ps, 700Hz-100kHz

Frequency response

All ranges 20Hz–20kHz ± 0.3dB (50Hz–16kHz ± 0.1dB)
176.4kHz, 192kHz : 16Hz–55kHz ± 0.5dB

THD+n

–117.5dB A-weighted, audio band-limited, 1kHz, -60dB FS input
Maximum 0.004% at –1dB FS (1kHz)
Minimum 0.0008% at –13dB FS (1kHz)

Idle channel noise

113.5dB at 44.1kHz, CCIR-weighted, full bandwidth

Crosstalk

–109dB at 12kHz