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Focusrite Green Focus EQ

Preamp/Equaliser By Paul White
Published January 1997

Though it's not exactly cheap, the Green Focus EQ brings professional quality within reach of the serious project studio owner. Paul White does the'rite thing....

The Focusrite Green range of processors offers a cost‑effective alternative to the acclaimed Red range, and though it is still a premium product line, it is priced to appeal to serious project studio owners as well as professionals. Cosmetically, the Focus EQ has much in common with the Voicebox reviewed in the December issue of SOS — the front panel and case are combined into a single cast component, with the green anodised front panel peeping through the apertures in the curiously‑sculpted black case. The transformer coupling of the Red range has been replaced by an electronically‑balanced alternative, and the PCBs use surface‑mount components so that manufacturing automation can be used to keep the build cost down. The circuitry, though, is pure Focusrite.

The Focus EQ combines a mic/line/instrument preamp (so that mic or line‑level signals can be routed directly to tape without needing to go through a mixer) with a single‑channel equaliser in a 1U‑high rackmounting unit. The XLR mic and line inputs and the line output are fully balanced and grounded to AES recommendations, while a further instrument‑level (guitar) input is provided on an unbalanced jack. Mains power is via an IEC mains socket, and the operating voltage may be switched to 120V or 240V by means of a recessed, rear‑panel slide switch.

Focus On Green

At the front end is a very low‑noise mic amp based around the Linear Technologies LT1028 mic amp chip used in the Voicebox. This provides 10‑60dB of mic gain with switchable phantom power, and phase inversion; further Mic and Inst buttons (in various combinations) enable the user to select the Line input, the Instrument input, or the Mic input. Each of the buttons has a built‑in status LED, and there's a 10‑section LED level meter above the preamp controls to help in optimising the preamp gain. The Instrument or Line input gains are controlled by the Input Trim knob, from ‑12 to +12dB.

There are three different types of filter in the EQ section, where the first line of defence is an independently bypassable section comprising one high‑cut and one low‑cut sweepable‑frequency shelving filter. These operate from 10Hz to 320Hz and 4.7kHz to 30kHz — anyone who's used a Drawmer DS201 with the filters in key listen mode will have a fair idea of what to expect. If you just need to trim some unwanted bandwidth from either end of the audio spectrum, these are the filters to do it.

The main part of the equaliser is configured as four bands; there are variable‑frequency, variable‑cut/boost filters at the extremes, plus two fully parametric mids. The low section can be swept between 30Hz and 470Hz, while the high shelving filter covers the 3kHz‑18kHz range, and each has a switch enabling it to be set to either shelving or bell mode. In bell mode, it behaves as a conventional sweep‑type equaliser, and up to 18dB of cut or boost is available in either mode. All the cut/boost pots have a positive centre detent.

Taking care of the mid‑range are the two parametric sections, each of which may be switched to cover different frequency ranges. The x3 Frequency button causes the low section to span the range 40Hz to 1.2kHz, while the high section can span 600Hz to 18kHz. Between these two controls, the entire audio spectrum can be covered, with a useful degree of overlap. Each section may be varied from a Q of 0.3 to 1.8, and the Q values are kept fairly low. A separate bypass button takes the main equaliser section out of circuit, independent of the high and low filters.

Unlike the equaliser built into the Voicebox, the Focus has true parametric mid sections, and the Q range seems to have been chosen for gentle, musical EQ rather than for radical notching. The available cut/boost range is probably more than most people will use, which is better than not having enough, but you do have to use it with care. The EQ on the high/low filter section is extremely powerful, and most sweetening jobs won't tax it at all.

At the end of the signal chain comes the output level control, which has an overload, clip‑warning LED. Right next to it is a yellow LED set into the front casting, to show that the unit is on.

Green Sound

A good equaliser will have plenty of circuitry headroom, a smooth phase response and a good transient response. Many commonly‑used ICs don't have the necessary power‑bandwidth capabilities to do the job without introducing an unacceptable level of distortion, but Focusrite designs are properly engineered and use components equal to the task. Furthermore, although the mic amp might almost be considered an add‑on, it still behaves impeccably.

Different EQ units all have their own character — some are hard and obtrusive, whereas others seem wishy‑washy and never really get a grip on the sound they're working with. All too often, the result sounds coloured, unnatural, and sometimes even distorted in some way. Focusrite's EQ behaves as do most of the best EQs I've heard, in that it is quite assertive, but it doesn't create phasiness or unnatural coloration, even when you apply it generously. The original idea of EQ was to provide something that would act like a volume control in selected parts of the audio band, so that instruments could be lifted out of the mix, and that's exactly what this one does. When you turn up the treble, the impression is not so much that you've added treble, but more that the bright components of the mix have become louder. Similarly, you can tighten up a bass sound without it spilling into the low mid or becoming flabby and unfocused.

For most applications, you'll only need a fraction of the available EQ boost, but even when heavy EQ is applied, the sound still retains its integrity. Particularly impressive is the way in which the Green EQ allows you to boost bass sounds and tighten them up at the same time.

Ergonomically, the only slightly weak point of this unit is that it's not always obvious which knob is which — the legending is quite small and the individual controls aren't named, so you have to figure out their function from their units of calibration. Even so, it doesn't take long to learn your way around.


This EQ is by no means a budget unit, especially when you consider that you only get one channel, but it is significantly cheaper than its more sophisticated Red‑series equivalent, and it behaves like a true top‑end device. Having a built‑in mic amp means you can use it as a direct‑to‑tape voice or instrument channel, but there's no insert point between the mic amp and equaliser, so you can't patch in a pre‑EQ compressor. The inclusion of an instrument input is also very valuable, but it suffers from the same limitation — many guitar and bass sounds work better when compressed pre‑EQ. These minor criticisms aside, this EQ is a superb performer and its simplified format (compared to having fully parametric EQ in all bands) doesn't seem to compromise its usefulness, yet makes it quite easy to set up. The sad thing is that a great many people don't realise how limited their existing EQ is, and until more people are exposed to EQs of Focusrite's calibre, they may never realise what they're missing.


  • Supremely transparent sound.
  • Predictable, intuitive operation.
  • Easy to spot in your rack!


  • No pre‑EQ insert point.
  • Control functions not immediately obvious, due to small print and lack of individual control names.


Though not cheap, the Greens allow users to buy into Focusrite quality for considerably less than the cost of the Red range. This model sounds just the way you always hoped EQ would sound.