Focusrite ISA-110
The single-channel module that became the most popular outboard mic-pre and EQ in studios worldwide, and the reason Focusrite keeps reissuing it.
Overview
The ISA 110 is a microphone preamplifier and equalizer module. Its story is the story of the Focusrite name. According to EQ (April 2000, p.57), the Studio Console that carried the Focusrite badge was based on the ISA 110 Microphone Preamp and EQ module. George Martin originally commissioned that module in 1987 for Air Studios in London, to extend his custom console. EQ (September 2000, p.113) adds the next step: the ISA 110 Mic Preamplifier and Equalizer was designed for the custom Neve console installed at AIR Lyndhurst Studios in 1992. From there it became the most popular outboard mic-pre and EQ in leading studios worldwide. It started as a module built to order for one room and ended up a standalone rack piece used across the industry.
Per the same EQ report, the physical build is a big part of it. The push buttons are Swiss-made. The pots are manufactured in France using conductive plastic for maximum accuracy and smooth feel. The equalizer's shelving bands use rotary switches. Conductive-plastic pots track accurately, where cheaper ones tend to go scratchy after a decade or so.
Mix (August 1987, p.23) ran a testimonial page. Kevin Mills of Larrabee Sound called the gear "quiet, transparent, and very musical," and Robert A. Tis of Electric Lady Studios described it as "one of the jewels of the industry" whose true value was yet to be realized. That's advertising-adjacent copy and should be read as such. Still, the names attached to it are working studios, not a marketing department, and Electric Lady put its technical chief's name on the quote.
The module also turned up in the field as a problem-solver. A Recording Engineer report describes a live performance at England's Marquee Club where blues guitarist Jeff Healey was recorded without a console, using Focusrite modules. ISA 110 input signal amplifiers fed drums, vocals and bass direct to multitrack, and two ISA 130 dynamics processor modules handled light compression on the lead and backing vocal tracks. Engineer Barry Farmer cited both the sound quality and the simple fact that there wasn't room for a console.
A Recording Engineer list of classic products also includes the module. The ISA 110/115 mic pre-amps appear among the nominees for the publication's rundown of the gear that mattered, alongside the Pultec EQ, the Neve 80 series console, the UREI LA-4, and the EMT 250. That's a nomination, not a final placement.
By 2000, Focusrite was reissuing the module as a limited-edition rackmount unit, and EQ (September 2000, p.113) notes the company presented Serial No. 001 of that run. Mix (June 2000, p.146) describes the reissue as a limited-edition version of the famed single-channel ISA 110 EQ module, with the same Swiss push buttons and French conductive-plastic pots. The limited run kept it scarce.
A lot of products carry "ISA" branding, and they are not the same thing. The ISA 828, for instance, is an eight-channel transformer-based preamp in a 2RU chassis. Its preamps are described as using the same vintage microphone pre-amplifier design as the original ISA 110 module, which makes it a descendant, not the module itself. The ISA 110 is the single-channel mic-pre and EQ, and that's the piece the period coverage is talking about.
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