The ISA430 MkII brings together a set of classic Focusrite heritage elements:
· Classic Focusrite ISA transformer-based mic pre with variable input impedance
· Versatile equalisation including two dual-range parametrics, HPF and LPF
· Dual-mode compressor with both VCA and optical circuitry
· VCA-based expander/gate with "hysteresis" setting to avoid chattering
· Phase-cancellation de-esser for more natural processing
· Optional 192kHz/24-bit A-D conversion with soft limiter
Together, they form a comprehensive channel strip with impeccable specifications. But the ISA430 MkII is much more than that. The four main elements – mic pre, EQ, Dynamics and A-D converter – can be accessed individually and each used as a separate processor. Elements can be chained and patched together via multiple inserts and in different orders to form a variety of signal paths to meet every processing requirement. Used as either a comprehensive channel strip or as separate processors, the ISA430 MkII offers you the pinnacle of classic Focusrite analogue processor design and performance. There’s simply nothing quite like it.
Classic Focusrite ISA Mic Pre
The mic pre features a transformer-based design, with variable input impedance from 600 to 6800 ohms – so it will get the best out of any microphone, from modern condensers to the most finicky ribbon types. Depending on your choice of setting, you can maximise flatness and transparency or deliberately bring out the special features of your chosen mic, such as a presence boost or high/low-end rolloffs. And there’s a special “air” button that brings in an inductor to enhance the effect without needing additional EQ.
Versatile Dual Mode Compressor
The compressor section features both a transparent VCA circuit, which can be used to apply significant amounts of compression without audible artefacts, and a vintage optical design that brings with it the characteristic feel of a traditional compressor. Optional auto release and “blend” control add to the section’s flexibility, the latter by allowing mixing of the original signal with the compressor output, maintaining as much as possible of the natural dynamics without losing the benefits of compression.
The Gate/Expander section is based on a transparent VCA design and includes a “hysteresis” setting that stops the gate chattering on difficult signals, while the de-esser is based on phase cancellation at the chosen frequency, rather than being compressor-based, leading to improved naturalness of sound.
Focusrite ISA 110 Derived EQ
The EQ section is exceptional, with HPF and LPF, two separate bands of parametric EQ (each with normal and x3 ranges for maximum versatility), and HF and LF shelving sections. In addition, individual parts of the equaliser can be switched into the side chain of the dynamics sections, allowing frequency-conscious compression, gate keying and other effects, while a “Listen” button allows you to audition the side-chain so you can tweak the EQ to get exactly the dynamics effect you’re looking for.
Class-Leading A-D Conversion
And finally, there is an optional A-D converter card which adds two channels of flawless 24-bit A-D conversion at sample rates up to 192kHz and with 120dB of dynamic range, preceded by a soft limiter to prevent clipping. Like the other parts of the ISA430 MkII, it can be used as part of the channel strip or as a completely independent unit.
The Most Versatile Channel Strip
Bring these elements together and you have the most versatile analogue channel strip available, with uniquely flexible patching and routing in addition to four powerful processors that can be used completely independently. And all with that unique Focusrite heritage sound. The ISA430 MkII. Nothing sounds like it – in so many ways.
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 A-D conversion.
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.
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.
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.
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.
· Gain Range: +10dB to +40dB continuously variable
· Input Impedance: >1M Ohm
· 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
· Ratio: 1.5:1 to 5:1 in Comp mode, 5:1 to 20:1 in Lim mode
· Slope: Soft knee in Comp mode, Hard knee in Lim mode
· Attack: Fixed
· Release: Fixed
· Low Pass Filter: 18dB/oct from 400Hz to 22kHz
· High Pass Filter: 18dB/oct from 20Hz to 1k6Hz
· Parametric section is 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 is comprised of: High Frequency Shelf: The frequency range steps are 1.5kHz, 3.3kHz, 6.8kHz and 15kHz (2.2kHz, 4.7kHz, 10kHz and 18kHz when Hi Range is engaged). Low Frequency Shelf: The frequency range steps are 20Hz, 56Hz, 160Hz and 460Hz (33Hz, 95Hz, 270Hz and 655Hz when Hi Range switch is engaged)
· 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
· Threshold Range: 22dB
· Frequency Range: 2k2 to 9k2
· Ratio at centre frequency: 2:1
· Threshold Range: 20dBu
· Ratio: infinite (Brick Wall)
· Attack: Frequency dependent
· 484mm (W) x 85mm (H) x 250mm (D)
· 19" (W) x 3.5" (H) x 9.8" (D)
Optional A-D Converter Specifications
Output formats (All channels)
· AES/EBU (5V / 110 ohms), S/PDIF (0.8V / 75 ohms)
· ADAT lightpipe (SMUX I/II/IV)
· S/PDIF lightpipe
· 24 bits
AES3 output jitter
· <:500ps, 50Hz-100kHz
· <:400ps, 700Hz-100kHz
· All ranges: 20Hz–20kHz ± 0.3dB (50Hz–16kHz ± 0.1dB)
· 176.4kHz, 192kHz : 16Hz–55kHz ± 0.5dB
· –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
· –109dB at 12kHz