Focusrite Saffire Pro 40
Eight Focusrite preamps, twenty channels of FireWire I/O, and a DSP mixer that let a project studio track a full band without waking the computer.
Overview
Eight mic preamps is the number that matters here. The Saffire Pro 40 is a 20-in / 20-out FireWire interface built around eight Focusrite preamps, and that preamp count is what made it a workhorse for small studios that needed to track a drum kit and a rhythm section at once. Focusrite's own Saffire range literature positions the Pro 40 squarely in the middle of the line — above the two-preamp Saffire Pro 24 and Pro 24 DSP, below the flagship Liquid Saffire 56 with its 28 in / 28 out count and Liquid modeling preamps. The Pro 40 is the one you bought when you needed channels more than you needed flavors.
The conversion is professional 24-bit / 196kHz, and Focusrite's range documentation credits the interface with JetPLL jitter elimination — the company's proprietary clocking scheme, which the marketing copy lists alongside the preamps as a headline feature. Whether JetPLL lives up to the brochure is a matter of debate among owners, but the spec sheet promise is there: professional-grade conversion with jitter suppression handled on the interface side rather than left to the host computer. The preamps themselves are described in Focusrite's literature as "based on a 25-year preamp legacy," which is marketing language for the company's long history building console and outboard mic pres — the ISA line among them. The Pro 40's pres are not ISA pres, and Focusrite never claimed they were; they are the house preamp sound at a project-studio price.
Where the Pro 40 earns its keep is routing. Focusrite's range copy describes an "ultra-low-latency intuitive DSP mixer/router with quick one-click set-ups" — in practice, an internal mixer that lets you build custom headphone mixes and apply DSP routing without leaning on the host CPU. For a band tracking live in one room, that means each player can get a different monitor mix straight off the interface while the computer sits idle. It is the kind of feature that reads as a bullet point on a spec sheet and becomes indispensable the first time you use it.
The rear panel carries ADAT optical connectivity and MIDI I/O, and those two ports are why the Pro 40 stayed relevant long after FireWire itself faded. Mix (April 2012) described the unit as a way to "expand your studio," noting the eight preamps make it ready for full-band recordings and that the internal DSP lets you create custom headphone mixes without tapping the computer's processing power. More telling is how engineers actually deployed it: Electronic Musician documented a project studio pairing a Saffire Pro 40 with a Universal Audio Apollo Twin over ADAT to build a 10-mic-input system, and specified a Windows rig running two Pro 40s chained together via ADAT Lightpipe for a 16-preamp front end. The same piece called the Pro 40's preamps "solid performers and well-priced" — faint praise, perhaps, but praise from a working engineer building a real room around them.
That ADAT expansion is the Pro 40's long game. Eight analog preamps plus eight more channels over optical means the interface grows with the studio rather than capping it.
FireWire is the obvious caveat. The Pro 40 is a FireWire interface, and FireWire has been effectively dead on new computers for years. Running one today means a FireWire port, a Thunderbolt-to-FireWire adapter chain, or a legacy machine kept alive specifically for audio — and driver support on modern operating systems is the perennial question mark for any interface of this vintage. Prices on the used market reflect that: these trade well below what eight Focusrite preamps and 20 channels of I/O would cost new, which is precisely the appeal.
For anyone assembling a first serious recording rig on a budget, the math is hard to argue with. Twenty channels of I/O, eight Focusrite preamps, 24-bit / 192kHz conversion, ADAT and MIDI, and a DSP monitor mixer — all for used-market money. The Saffire Pro 40 was never the flashiest interface in the Focusrite catalog. It was the one that showed up, plugged in, and tracked the band.
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