Overview

The ISA 220 Session Pack provides all the audio precision tools required to infuse your session with Focusrite’s renowned sonic performance. It features many of the original circuits of the flagship ISA 430 MKII Producer Pack, and also includes some new facilities of its own. It also features the same digital output option as the originalISA 430, providing you with a high quality digital route direct fromthe ISA 220 into your digital recording system.

The ISA 220’s input stage features a precise VU meter, switchable to allow the user to monitor either input level or compressor gain reduction. Situated above the VU meter is a 32 LED digital meter for monitoring both the ‘internal’ input and the rear panel ‘external’ input (the latter routes directly to the second channel of the optional high quality stereo A/D card). A global bypass switch is located to the right of the digital meter to allow for instant A/B comparisons. Mic, Line and Instrument inputs allow interfacing to any input device, and are all transformer-based, the cornerstone of the focusrite signature sound clear yet warm, with incredibly low noise figures and a THD below 0.001% on the mic input! Switching between these input options is available on the front fascia with LED’s indicating the active input.

The Mic Pre is the classic Focusrite transformer-based design as featured in the ISA 110 with illuminated switches for phantom power and phase reverse, all immediately available on the front fascia. Further front panel switchable controls allow control over the Digital output option and in/out selection for each of the processors. An instrument jack is provided on the front panel for quick ‘plug and play’ access. The EQ featured on the ISA 220 is similarn to the ISA 430 MK II and ISA 110, except that the Shelving EQ features four frequency selections rather than six or eight. Whether fattening-up bass, foregrounding or trimming middle, or adding airy top, this EQ can handle anything. Next to the Compressor section (which utilises the same compressor circuit as the ISA 430 MK II) the ISA 220 features a ‘Compressor Pre EQ’ switch. This allows the user to place the Compressor either pre or post-EQ. A new feature in the compressor section alongside the auto release is the Blend control, a unique ISA feature, allowing smoother compression at more extreme settings.

When switched in, ‘Blend’ allows you to mix the uncompressed signal with the compressed, thus retaining the power of the dynamics from the original source. The ISA 220 also includes the same De-esser as the ISA 430 MK II, based on a low distortion optical technology design, letting you transparently remove excessive sibilance from a vocal performance. The output section of the ISA 220 features the same frequency adaptive limiter as the ISA 430 MK II, a design which uses three separate stages of optical-based circuits, each of which has different limiting properties to give true distortion-free limiting. Fast limiters tend to have problems dealing with complex signals that contain sustained low and mid frequency information and thus “chop holes” in the audio when HF transients trigger the limiting. To overcome this, the ISA 220’s frequency adaptive limiter has three frequency bands with different attack times as follows: LF slow, MF quick and HF ultra-quick, the latter designed to catch fast transients. The Limitin LED illuminates when the limiter is active.

An upper threshold is fixed at +20dBu to prevent overload of the internal (or an external) A/D converter. ISA 220: Session Pack Classic Focusrite transformer-based Mic pre New Focusrite EQ featuring elements of the original ISA 110 EQ circuit Hi and Lo pass filters Precision VU metering of input level or compressor gain reduction (switched) Proprietary Focusrite discrete Class A VCA Compressor design for better distortion and noise figures Order of compressor and EQ modules in the signal path can be
switched from the front panel New Blend feature allows uncompressed dynamics to be merged with the compressed signal path De-esser design based on optical technology for lower distortion and transparency De-esser listen for independent monitoring of isolated sibilant signals Frequency-adaptive limiter to prevent critical digital overloads Optional Stereo A/D – 24 bit 96 KHz Delta Sigma converter running at 128KHz over-sampling – Dithers down to 20 or16 bit The ISA 220 Session Pack provides all the audio precision tools required to ninfuse your session with Focusrite’s renowned sonic performance. It features many of the original circuits of the flagship ISA 430 MKII Producer Pack, and also includes some new facilities of its own. It also features the same digital output option as the originalISA 430, providing you with a high quality digital route direct fromthe ISA 220 into your digital recording system.

Spesification

Inst. Hi Z I/P
• Noise: -96dBu
• THD: 0.003% with 0dBu

Mic I/P
• Noise: 123dB EIN with 150 Ohm input resistance at 60dB of gain
• THD: 0.0008%

Compressor
• Threshold Range: -28dB to +12dB
• Ratio: 1.5:1 to 10:1
• Slope: Soft knee
• Attack: 500ms to 25ms
• Release: 100ms to 4s, variable or auto (program dependent)

De-Esser
• Threshold Range: 22dB
• Frequency Range: 2k2 to 9k2
• Ratio at Centre Frequency: 2:1

Limiter
• Threshold Range: 20dBu
• Ratio: infinite (Brick Wall)
• Attack: Frequency dependent

Weight
• 7kg
• 15.4Ibs

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