Sound Is Everything

Focusrite has a reputation for being somewhat obsessive about sound quality. That’s why our slogan is “Sound Is Everything”. Focusrite is the acknowledged expert in computer audio interface design – we’ve been doing it for a very long time – and it’s hardly surprising that we’ve given sound quality – as evidenced by the mic pres and digital converters – special attention in our interfaces.

Building on the Focusrite Heritage

Focusrite’s experience with microphone preamps goes back over four decades to the dawn of the company – and to the original modules designed by console legend Rupert Neve for Sir George Martin’s AIR Studios. Under a decade later, the first Focusrite digital conversion system was part of the Blue (mastering) range, released in 1993 and acclaimed by the most critical of users, the world’s mastering engineers. Then Digidesign (now Avid), came to Focusrite for their first Pro Tools home studio interface, the MBox, in 2000. It’s no wonder that today’s Focusrite interfaces are widely regarded as market leaders, and remain, especially with the advent of the Red 2 and Red 3 AAX plugins, free of charge with every interface, perfect partners for Pro Tools.

Let’s take a look at those central pillars of Focusrite interface sound quality – the Mic Pres and the Converters – a little more closely.

The Mic Pre – getting it right

Focusrite has been known for its Mic Pres since the founding of the company in 1985, and we have a world-wide reputation as a leader in the field. The designs we use in our computer interfaces were specially developed for the purpose, and use a 2-stage topology for maximum performance, with exceptional ability to respond to rapid changes – aka high slew rate – for dynamic accuracy. Each stage is optimised for its tasks: the first stage is built for ultra-low noise and is designed around an op-amp specifically designed as a mic pre – and in some cases, a chip purpose-built to our specifications – with optimised noise and headroom. The second stage is designed for high gain, wide frequency range, superior rejection of unwanted input signals (technically known as common mode rejection) and low noise. The limitation of power supplies in an interface also mean that chips need to be selected that offer maximum headroom under these conditions. Power supplies are designed with the right component values to support the operation of the amps – in many cases we use a bipolar power supply for extended headroom. The components around the op amps are carefully chosen. The input capacitors are carefully selected for LF response, and the input impedance is precisely set. Thirty years of design experience lies behind our mic preamps, but they also use the latest circuit elements and techniques. And at the end of the day, their purpose is simple: to capture your original sound, accurately and authentically.

Precision Digital Conversion

It’s over 20 years since we released our first digital conversion system, and it’s fair to say that today Focusrite is as well-regarded for its converters as it is for its mic pres. The multi-bit delta-sigma converter chips we use are chosen for the balance between dynamic range and distortion, for their natural sonic performance, and for minimum latency in the anti-aliasing filter – always shooting for maximum sound quality. We use a differential analogue architecture for best noise performance, wide dynamic range and negligible distortion. Wherever you have analogue and digital parts of a device right next to each other, as you do with the actual converter chips, component placement and board design is more important than ever. We use careful component and track positioning, and multi-layer boards with internal ground planes to minimise crosstalk and digital noise getting into the analogue side. During the course of developing a design, we carry out an FFT analysis of the noise floor to be sure it’s clear of digital artefacts. Sometimes we even have to design workarounds to compensate for design decisions inside the chip. And at Focusrite, our published system specifications derive from actual measurement in the real world and not simply from reprinting the chip’s spec sheet – our products are measured in operation, not on paper.

Choosing an interface

While in the early days, the performance of Firewire as a computer interface was superior to the original (version 1) USB interface, the advent of USB 2.0 and Firewire 800 offered connections that had more than enough bandwidth for recording and playing multichannel music even at high sample rates. Today’s Thunderbolt interfacing is similarly overspecified for audio, and you can of course run any of Focusrite’s Firewire interfaces via a Thunderbolt-Firewire adaptor.

And now, with the advent of the next-generation Clarett range of native Thunderbolt interfaces, Focusrite takes another major step forward with a level of interface latency that’s under 1ms – similar to that of Pro Tools HDX – along with a new mic pre that delivers the unique heritage sound of the coveted ISA range alongside ultimate transparency and accuracy.

Thus today, the choice of interface format may be a matter of convenience and which product offers you the feature combination you want. And bear in mind that it’s also helpful to have your audio coming in and out via an interface you’re not using for something else – particularly hard drives. So for example, if your drives are USB, use Firewire or Thunderbolt interfaces, or vice-versa.

Focusrite’s computer interfaces are compatible with all major DAWs, and make a perfect partner for Pro Tools – especially with the advent of the Red 2 and Red 3 AAX plugins, supplied with every unit. Carefully designed to deliver best-in-class mic pre performance and precision digital conversion, a Focusrite computer audio interface is an excellent choice for all your digital recording needs.