The ISA Two from Focusrite is a dual mono microphone preamp featuring transformer based microphone inputs with variable input impedance. Based on the legendary designs found in the Focusrite Forte and Studio consoles, the preamps provides up to 80 dB of gain, while two front panel instrument inputs allow for immediate access to two transparent DIs.

The microphone inputs feature a pair of Lundahl LL1538 transformers with a 3-section winding that results in very low leakage inductance, along with an extended frequency response. To shield them from stray magnetism, each is encapsulated in mu-metal cans. Each channel has a fully-balanced insert point, activated using a front-panel button, making it easy to insert a choice of outboard EQ, a compressor, or limiter.

A premium bonus is the Brainworx bx_console Focusrite SC channel-strip plug-in, a stellar digital emulation of the legendary and rare Focusrite Studio Console. Only 10 of the consoles were ever produced, but you can access its famed sound directly in your DAW.

Microphone Input Transformer

Includes Lundahl LL1538 input transformers, originally chosen by Rupert Neve for the ISA 110 and one of the best microphone input transformers available

Zobel network in the ISA circuit (perfected by Rupert Neve) allows the microphone preamp to maintain an extremely flat frequency response across a very wide bandwidth

Gain

Offers up to 80 dB of clean, distortion-free gain

ISA topology ensures low-noise even at the highest gain levels

The transformer supplies 20 dB of gain, while the ISA's input stage offers up to 60 dB of additional gain on the microphone input

Variable Input Impedance

Four choices of input impedance, including the original ISA 110 value, allow for matching the preamp to a different microphones, even a vintage type, for the best possible sound

Impedance is selected using a switch on the front panel

Impedance choice is remembered even when the unit is switched off and back on

User-Calibrated Metering

Each channel has an eight-LED array to clearly display the level of the two signals

Line up the analog levels with digital converters or a DAW by using the calibration knob on the rear panel

Calibration avoids clipping on input

Instrument and Line Inputs

Two 1/4" TS connectors on the front panel provide access to a transparent DI input

TRS line inputs are available on the rear panel and a front panel switch allows for stepping through them to instantly select required input

Variable High-Pass Filter

Smooth-sounding, built-in 18 dB/octave high-pass filter per channel

Same design as the original ISA 110 module

Ideal for cutting out rumble, thumps and other unwanted low-frequency sounds using the 16 Hz to 420 Hz range

Easily accessed with a large knob and illuminated button

Balanced Inserts

Each channel has its own balanced insert point via 1/4" TRS send and receive connectors

Allows for a choice of signal processor to be connected and switched in and out using the illuminated switch on the front panel

Focusrite Console Plug-In

Includes Brainworx bx_console Focusrite SC channel-strip plug-in, a stellar digital emulation of the legendary and rare Focusrite Studio Console

UPC: 815301005148

Focusrite ISA-2 Specs

Number of Channels 2

Multi Function No

Inputs 2 x 1/4" TS phone Instrument (front panel)

2 x XLR Microphone (rear panel)

2 x 1/4" TRS phone Line (rear panel)

2 x 1/4" TRS phone Return (rear panel)

Input Impedance Mic (@ 1 kHz): Low = 600Ω, ISA 110 = 1.4Ω, Medium = 2.4Ω, High = 6.8 kΩ

Line: 10 kΩ from 10 Hz to 200 kHz

Instrument: >2 MΩ

Maximum Input Level Mic: +7 dBu with a THD+N <0.7% at 1 kHz measured at 0 dB of gain with 150Ω source impedance and 22 Hz to 22 kHz band-pass filter

Outputs 2 x XLR

2 x 1/4" TRS phone Send

Maximum Output Level +24 dBu with a THD+N <0.01% at 1 kHz measured with 150Ω source impedance and 22 Hz to 22 kHz band-pass filter

Phantom Power +48V, individually switchable

Gain Range Mic: 0 dB to +60 dB in 10 dB steps, plus 0 dB to +20 dB continuously variable trim

Line: -20 dB to +10 dB in 10 dB steps, plus 0 dB to +20 dB continuously variable trim

Instrument: +10 dB to +40 dB continuously variable trim

Frequency Response Mic @ minimum gain (0 dB): 10 Hz to 135 kHz, -0.5/1 dB

Mic @ +60 dB gain: 10 Hz to 115 kHz, -6/-1 dB

Line @ unity gain (0 dB): 10 Hz to 80 Hz, -0.3/-1 dB

Instrument @ minimum gain (+10 dB): 10 Hz to 115 kHz, -0.1/1 dB

Instrument @ maximum gain (+40 dB): 10 Hz to 110 kHz, -2.5/1 dB

EIN -127 dB (60 dB of gain with 150Ω source impedance and 22 Hz to 22 kHz band-pass filter)

Noise Mic: -97 dBu @ output with unity gain (0 dB) and 22 Hz to 22 kHz band-pass filter

Line: -97 dBu @ output with unity gain (0 dB), measured with 50Ω source impedance and 22 Hz to 22 kHz band-pass filter

Instrument: -95 dBu, minimum gain (+10 dB) with 22 Hz to 22 kHz band-pass filter

Signal to Noise Ratio Mic: 121 dB, with +24 dB maximum output (150Ω source impedance and 22 Hz to 22 kHz band-pass filter)

Line: 121 dB, with +24 dB maximum output (50Ω source impedance and 22 Hz to 22 kHz band-pass filter)

THD + N Mic: <0.0007% @ 1 kHz (-20 dBu input signal with +30 dB gain and 22 Hz to 22 kHz band-pass filter)

Line: <0.002% @ 1 kHz (0 dBu input signal with +10 dB gain and 22 Hz to 22 kHz band-pass filter)

CMRR Mic Input @ 60 Hz: -94 dB, with +24 dBu maximum output

Mic Input @ 10 kHz: -91 dB, with +24 dBu maximum output

Crosstalk Mic: -85 dB (I/P = 0 dBu, gain = 0 dB @ 1 kHz input to channel A, channel B output)

Line: -91 dB (I/P = 0 dBu, gain = 0dB @ 1 kHz input to channel A, channel B output)

Power Requirements 100~240 VAC, 50/60 Hz

Dimensions 19 x 11 x 1.7" (480 x 280 x 44 mm)

Weight 8.2 lb (3.7 kg)

Specialties 18 dB per octave (3-pole) high-pass filter, continuously variable from 16 Hz to 420 Hz (-3 dB)

Packaging Info

Package Weight 12 lb

Box Dimensions (LxWxH) 25.8 x 14.8 x 5.2"