Focusrite ISA Two 2 Channel Rack Preamp - Secondhand

Full Description

Classic Focusrite sound with modern enhancements

At the heart of the ISA Two are two independent mic preamps based on the original ISA 110 module, designed by Rupert Neve. These preamps use the Lundahl LL1538 input transformer, delivering the warm, rich character that has made Focusrite’s ISA series a favourite among engineers and producers. The combination of transformer-based circuitry and solid-state design results in a clean, low-noise signal path with incredible depth and clarity.

To enhance flexibility, Focusrite has incorporated four selectable input impedance settings. These allow users to match the preamp to any microphone, from vintage ribbon mics requiring a traditional impedance load to modern condensers that benefit from a more transparent response. The ability to adjust impedance ensures that every microphone performs at its best, capturing the full tonal character of any source.

Powerful gain and flexible input options

With up to 80dB of gain, the ISA Two is designed to handle low-output microphones without the need for additional preamplification. The first four-position rotary switch provides up to 60dB of gain, while an additional +20dB trim control allows for fine adjustments, ensuring optimal signal levels for any recording scenario.

In addition to its mic inputs, the ISA Two features front-panel instrument inputs for direct recording of guitars, basses, and other high-impedance sources. The rear-panel includes TRS line inputs, making it easy to integrate with external gear. Whether tracking a vocal session, capturing a stereo piano performance, or running a direct guitar signal, the ISA Two provides the connectivity needed for a variety of recording applications.

Precision control with high-pass filtering and metering

The ISA Two includes a variable high-pass filter, allowing users to clean up low-end frequencies that may introduce unwanted rumble or noise. With a smooth 18dB/octave slope and a fully adjustable cutoff range from 16Hz to 420Hz, the filter ensures that recordings remain clear and free from unnecessary low-frequency buildup.

Accurate level monitoring is crucial for achieving the best recordings, and the ISA Two features user-calibrated eight-segment LED meters for each channel. A rear-panel calibration knob allows users to match the metering to their digital converters or DAW, ensuring that input levels remain well-controlled and free from clipping. This provides an added level of precision when setting gain levels, helping to maintain signal integrity throughout the recording process.

Seamless integration with external gear

To enhance workflow and flexibility, the ISA Two includes balanced insert points for each channel, allowing external processors such as EQs, compressors, or effects units to be integrated into the signal chain. These insert points use standard 1/4-inch TRS send and return connections, with an illuminated front-panel button for quick activation. This makes it easy to add dynamic processing or tonal shaping to signals before they are recorded, without the need for additional routing.

Features

• Transformer-based mic preamplifiers
• Variable input impedance
• Up to 80 dB of clean, low-noise gain
• Variable cut-off high-pass filter
• Eight-segment user-calibrated LED meter per channel
• Two front panel instrument inputs
• Dedicated per-channel insert point
• 1U 19" rack-mount format

Specifications

Mic Input Response

• Gain Range (Mic): 0 dB To 60 dB In 10 dB Steps, Plus 0 dB To 20 dB Continuously Variable Trim
• EIN (Mic): Measured At 60 dB Of Gain With 150 Ω Source Impedance And 22 Hz-22 kHz Band Pass Filter -127 dB
• Noise (Mic): Noise At Output With Unity Gain (0 dB) And 22 Hz-22 kHz Band Pass Filter -97 dBu
• Frequency Response (Mic): At Minimum Gain (0 dB) -0.5 dB At 10 Hz, -1 dB At 135 kHz, Relative To 1 kHz
• At 60 dB Gain (Mic): -6 dB At 10 Hz, -1 dB At 115 kHz, Relative To 1 kHz
• Crosstalk Channel To Channel (Mic): Mic Input, With I/P = 0 dBu, Gain = 0 dB @ 1 kHz Input To Channel A, Channel B Output = -85 dB

Line Input Response

• Gain Range (Line): -20 dB To 10 dB In 10 dB Steps, Plus 0 dB To 20 dB Continuously Variable Trim
• Input Impedance (Line): 10 kΩ From 10 Hz To 200 kHz
• Frequency Response (Line): At Minimum Gain (0 dB) -0.3 dB At 10 Hz, -1 dB At 80 kHz, Relative To 1 kHz
• Crosstalk Channel To Channel (Line): Line Input, With I/P = 0 dBu, Gain = 0 dB @ 1 kHz Input To Channel A, Channel B Output = -91 dB

Instrument Input Response

• Gain Range (Instrument): 10 dB To 40 dB Continuously Variable Trim
• Input Impedance (Instrument): 2 MΩ
• Noise (Instrument): Measured With 22 Hz-22 kHz Band Pass Filter Minimum Gain (10 dB) = -95 dBu
• Frequency Response (Instrument): At Minimum Gain (10 dB) -0.1 dB At 10 Hz, -1 dB At 115 kHz, Relative To 1 kHz
• At Maximum Gain (40 dB) (Instrument): -2.5 dB At 10 Hz, -1 dB At 110 kHz, Relative To 1 kHz

High-Pass Filter

• Roll-Off: 18 dB Per Octave (3 Pole Filter)
• Frequency Range: Continuously Variable From 16 Hz To 420 Hz (-3 dB)

General

• Product Code: MOIFTWOAUKEU