Focusrite Platinum Tone Factory in very good condition

Minor Rack rash, Tested and Working Perfectly 

Paul White clocks on for a shift in Focusrite's Tone Factory, the first of the company's new low?cost Platinum range of processors, and discovers the anarchic side of Focusrite.

Focusrite are one of the big names in high?end signal processing, so they surprised everybody when they launched the lower?cost Green range (the first units of which were reviewed in SOS back in November '96). Their brand?new Platinum range signals a further decrease in price, as well as being conceptually quite different to what we've come to expect from the company.

The Focusrite sound is traditionally associated with transparency and sonic purity, but while the Platinum range borrows from some established Focusrite EQ topographies, it also provides the means to colour or even distort sounds in musically interesting ways. Focusrite designer Rob Jenkins explains that the company's existing products were built for studio engineers, while the Platinum range is specifically designed for recording musicians. He describes these new units as 'results?orientated products' rather than purist engineering tools.

The first Platinum unit to be launched is the Tone Factory, a 1U mains?powered rack unit that combines a class?A mic amp, variable?frequency high and low shelving filters, a compressor, a set of instrument?style tone controls (complete with overdrive and speaker simulator), a 2?band semi?parametric equaliser, and a noise gate. It's designed mainly for instrument use, but can also double as a mic channel if required.

Gone is the visual flamboyance of the Green range, to be replaced by a businesslike grained aluminium front panel, sober silk screening and pear?shaped buttons. The conical rubber knobs used in the Green range have been retained, but in most respects this is a radically different product to anything the company has made before, both cosmetically and electronically.

The Modules

This unit might best be thought of as a series of more?or?less independent modules wired in series, though it is possible to switch the high? and low?pass filters into the gate side?chain if required, to facilitate frequency?conscious gating. At the front end is a class?A preamp switchable to mic, line or instrument mode; the XLR mic socket and balanced line jack are on the back panel, while the unbalanced, high?impedance instrument jack is on the front. Unlike the Green series mic amp, which uses expensive specialist chips, this preamp is built from discrete bi?polar transistors and FETs, and has a soft saturation characteristic so that you can introduce some coloration by driving it hard. As well as the variable gain control, there's switchable phantom power and a simple dual?LED metering system, where green shows the presence of a signal and red signifies overload.

Next in the signal path is the high?/low?pass filter section, which is not quite as straightforward as it might seem, as there are two filter modes — normal and corrective. The corrective mode provides two 12dB/octave filters, with conventional curves, variable from 10?320Hz and 2kHz?30kHz respectively. In the normal mode the curves are under?damped, so there's a slight peak at the turnover frequencies, and the low filter's rolloff becomes more gentle so as to be more musical on bass sounds. A Gate button places the filters in the gate side?chain, while the To Audio button puts the filters in the main audio path. With both buttons out, the filters are out of circuit altogether.

According to Rob Jenkins, the compressor was an interesting design challenge, because Focusrite wanted to avoid low?cost VCAs that might adversely colour the sound, so they went to an opto design based around a photocell. This is quite a popular technique at the moment, no doubt inspired by the success of the JoeMeek range, but Focusrite have adopted a very different approach, by using a second opto cell in a feedback circuit to linearise the control law of the gain circuit. (Apparently, simpler opto designs tend to have an 'all or nothing' response because of their inherent non?linearity.) The only variable controls here are Threshold, Release and Output, with attack being switchable to fast or slow and ratio being controlled by the Hard Ratio switch. With the switch out the ratio is around 2:1, and when it's in this increases to 6:1. The compression law is a conventional hard?knee type, and a 6?LED meter monitors the amount of gain reduction taking place. A rear?panel TRS jack insert point allows processors such as equalisers to be patched into the compressor side?chain, for de?essing and similar tasks. As with the other modules, a bypass switch is fitted.

The Tone Factory offers a wealth of genuinely useful features, and combines the classically smooth Focusrite EQ sound with new creative potential.

Next on the list is the Tone Controller section, which is the part of this design that seems least like what you'd usually expect from Focusrite. The Tone Controller comprises an overdrive control, with its own bypass switch; a Bright switch, which brings in a speaker simulator filter when out; and a separately bypassable 3?band passive instrument EQ, based on the same type of high?impedance circuitry you'd expect to find in a guitar amplifier. The controls are designated Bass, Middle and Treble, in true instrument amp fashion, and the Treble control can be switched to operate as a high?mid control for use with guitars and basses. As far as I could ascertain, this EQ section has no completely flat position.

Following on is perhaps exactly the type of EQ module you'd expect from Focusrite, although (to keep the cost down and to conserve panel space) the variable Q of a conventional parametric has been replaced by a Normal/Fine switch. This module comprises two EQ sections which can be switched individually between shelving (one high?pass, one low?pass) and band?pass mode. Centre?detented gain controls provide up to +/?18dB of range, while the frequencies can be varied from 40Hz?1kHz and 500Hz?20kHz respectively. A single bypass button takes the Parametric EQ section out of circuit when it's not required.

A TRS jack insert point is fitted between the EQ section and the gate that follows, and a rear?panel sensitivity button selects +4dBu or ?20dBv operation. The idea behind including a ?20dBv setting, rather than the more usual ?10dBv, is that instrument pedal effects can be used. I get the impression that Focusrite envisage some musicians using the Tone Factory on stage as well as in the studio; to this end, the balanced +4dBu XLR main output is supplemented with a ?10dBu line output jack and a ?20dBu instrument output jack.

The final module is the noise gate, which is quite flexible even though it has only two variable controls. Threshold and Release are variable, but a switch turns the Release control into a Hold control, for creating gated reverb effects and so on. A Fast/Normal switch optimises the gate attack for percussive or non?percussive sounds, while the Deep button sets attenuation in the gate?closed position to either the maximum of 100dB or around 20dB. A single red LED shows when the gate is closed. When the shelving filters are switched into the gate's side?chain, it operates as a conventional frequency?conscious gate, and there's a rear?panel Gate Key jack, at a nominal 0dBu level, to allow the creation of externally triggered gating effects. At the end of the line is a Master Fader knob, a 6?LED level meter, and the power switch.

Working In The Tone Factory

Although the Tone Factory's mic amp design is very different to anything Focusrite have done before, it's still very quiet and, at normal gain settings, quite transparent. It's only when you drive it really hard that subtle coloration starts to creep in. It's probably fair to say, though, that it doesn't equal the Green front end's openness and transparency. The high and low?pass filters are extremely useful — I often use those on my Drawmer gates as instrument equalisers, so it's good to have them in addition to the more conventional EQ. The subjective difference between normal and corrective mode is quite evident, providing two distinct tonal flavours.

The compressor has something of the classic opto sound, but it's not nearly so pronounced as you might expect — largely, I suspect, because of the measures taken to linearise the gain?control process. The result is a compressor that you can hear working on all but the gentlest settings, but it's still very much under control and musical. The higher ratio combined with the longer attack setting is more aggressive and works especially well on guitar sounds to produce a nice glassy sustain, though there's plenty of scope too for effective vocal compression. Despite the simplified controls, the compressor seems to work fine on a wide range of sound sources.

I have to admit that I found the overdrive/Tone Controller section to be a little quirky, but as long as you accept that it's there purely to create instrument colours and not to act as a traditional equaliser, it can be a lot of fun. The overdrive is really a soft clipper based around FET circuitry and doesn't offer the kind of range you'd expect from a guitar overdrive box, though it works well to augment guitar sounds that have already been overdriven prior to processing. It's probably best used at lower settings to add thickness to synth sounds, guitars or basses — at higher settings, it has a tendency to light up the overload LED in the preamp section. Realistically, any guitar players using this box will almost certainly already have some form of overdrive device or preamp.

The speaker simulator controlled by the Bright button trims away most of the grittier harmonics of a guitar, though if the button is pushed in, to bypass the simulator filter, the sound is somewhat buzzy and ragged, as you might expect. The only way to describe the EQ is to say that it's very coloured, in the same way that a guitar amp EQ is coloured. It has a pretty good tonal range and, in conjunction with the other EQ sections, allows you do a lot of serious tone?shaping. Though there's no nominally flat setting, you can get close by setting the mid to maximum and the treble and bass to halfway.

The Parametric section is more familiar, with a flat position at the gain centre detents. As with other Focusrite designs, even when you pile on lots of boost you rarely get the impression that you're overdoing things. Having a choice of band?pass or shelving really adds to the flexibility of this section, and although Focusrite's next Platinum unit will be a voice?channel unit, the Tone Factory also doubles as a useful voice processor when the Tone Controller instrument section is switched off — you can actually get some interesting vocal effects with the Tone Controller switched in, as long as you don't expect them to be very natural!

Having the gate at the end of the chain helps keep noise under control, and it does its job very well. However, because the insert point comes before the gate, delay and reverb effects may suffer from truncated tails. For this reason it would probably be best to put such effects at the end of the chain, reserving the insert point for effects that don't create significant amounts of delay.