Optifile Drax

Optifile's new VCA‑based Drax system is designed to make professional‑quality automation affordable. Paul White finds out to what extent they've succeeded.

Named after a well‑known UK power station, (not the James Bond villain!), Drax is a relatively low‑cost VCA console automation system from Optifile, the designers of the professional Tetra system. Like Tetra, Drax is installed inside an existing mixer, so there are no external fader boxes or rack units to accommodate. If there's a disadvantage to this, it is that you have either to send your console away to have the system installed, or you have to pay extra to have an engineer fit the system in your home. Currently, systems have been installed in consoles such as the Mackie 8‑buss and the Soundcraft Ghost, but there's no reason at all not to fit Drax to more expensive consoles.

What You Get

The system is supplied as a basic package capable of automating 24 channels, then further blocks of eight channels are added as required, depending on the size of your console. Up to 32 channels can be driven in this way, and the system can be expanded right up to 64 channels by adding an extension card to the processor box. Circuit boards containing blocks of eight dbx 2150 VCA chips are wired to each fader, and if the automation system is switched off, a software bypass mode hands control of the VCAs back to the console faders. There's no way to bypass the VCAs, but the high‑quality signal path means this isn't a significant concern.

Unlike Optifile's Tetra, which comes with its own rackmount computer, the front‑end Drax software runs on a standard PC computer, so you'll also need the minimum of a Pentium PC running Windows 95 or Windows 3.1, and a colour monitor. When I asked Optifile whether the Drax software could run at the same time as a sequencer, I was told that at present this was unlikely, because of the heavy demands on the computer's processing power during busy mixes. However, Optifile are working on a new Windows driver, so this is likely to change.

A small interface box mounted on the rear of the mixing console (see the picture above left) handles the timecode input connection (Drax requires conventional SMPTE to operate), the PSU input to drive the VCA boards, and a link socket to the PC Com port. Drax can talk to either Com port 1 or 2, but if your mouse is already assigned to the same port as the Drax software, you'll have to use cursor commands to navigate to the Drax setup menu where you can change the Com port. After doing this, mouse and Drax will cohabit quite happily. The tools for configuring the system's number of channels, VCA/fader calibration and so on are available from the Utility menu, but as the system comes with the software ready‑configured, the end user shouldn't have to deal with any of this.

Once installed and booted up, the Drax user interface looks like the screen dump shown in Figure 1 (right). Up to 24 faders can be seen on screen at one time, and if you have more than 24 channels, the keyboard arrow keys let you jump along in blocks of eight, or one channel at a time.

Drax Features

VCA automation systems don't employ moving faders, but Optifile have always done their best to create a moving‑fader environment on screen, and the philosophy of their system has obviously absorbed some working practices from pro automated console manufacturer SSL. All fader moves are made from the actual console faders — there's no mousing about in cyberspace — and the console mute buttons are also tied into the system, allowing mute automation to be mixed with fader automation. There is one limitation concerning the mutes, and that is that Drax can't tell whether the mute is due to a mute button being pressed or by a fader being pulled all the way down. Inside a typical console, the mute button is wired straight across the channel fader, so there's no way an add‑on system can differentiate between the two.

As is normal with a VCA system, only the channel faders are automated, not the groups or masters, but Drax can be programmed with up to nine VCA subgroups (though you can't include the same channel in more than one group), and a master fade function is included that lets you specify the start time, end time and curve law of a fadeout. Both mutes and faders are handled independently, so they can be recorded or modified separately. If you feel you need overlapping VCA groups, you can always create your first group, record your moves, delete the group, then create a new one for the second stage of your plan. There are no off‑line editing facilities, but if you need to fix something, you just overwrite the old moves with new ones.

Mixes are recorded against timecode, so you have to have a system capable of supplying SMPTE. Drax has a virtual internal SMPTE generator for demonstration use, but this doesn't actually produce code — it just allows the system to run without an external code input. All popular SMPTE formats are catered for: 24 frame, 25 frame, 30 frame and 30 frame drop.

Unlike many budget automation systems, Drax uses a dual‑memory buffer system, so that it can hold your original mix moves, and at the same time, record new ones while you're making changes. The current mix resides in the base buffer, and as you record modifications, these are stored in a temporary buffer. After recording, you have the option to update the base buffer with the newly‑recorded information, or you can discard the last pass without altering your original mix. The colour of the Memory Free window changes from black to red when new data is recorded into the temporary buffer, indicating that you must keep or discard the last mix modification before proceeding.

Once the first mix pass has been recorded, playing back the mix shows the VCA moves as moving red bars at the centre of the virtual faders, while the on‑screen fader knobs always indicate the actual physical position of the console fader (unless a mute button is activated, in which case the screen fader will fall to its zero position). When the physical fader position and the VCA mix levels are the same, the on‑screen fader knob changes in colour to show that the two levels match, which is useful for avoiding jumps in level when punching in and out of new mix moves.

Mutes are either in Isolate mode, or they're in Absolute mode, while faders also feature an Update mode, of which more in a moment. In Absolute mode, any mute button presses or fader moves will be recorded when Drax is set to record, but because mutes and faders have their own status buttons, you can record both together or work on them separately. Isolate mode disconnects the selected faders or mutes from the computer so that they can be used manually. The Move mode of the Tetra system has been left out of Drax, but then few Tetra users seemed to appreciate the usefulness of this mode anyway.

Drax can be set to Safe mode (to prevent further mix data been accidentally written), or used in Rehearse mode, where all the new moves are heard in context, but not recorded — the Punch button toggles between Safe and Rehearse or Safe and Record, whichever is selected. The window beneath the counter display changes from red to green corresponding to Rehearse or Record modes. Optifile are also currently adding chevrons to the Record/Safe status button to assist any colour‑blind users.

Unlike Optifile Tetra, which has the option of local status buttons, allowing the user to punch in and out of mix record via buttons on the console itself, Drax handles status from the computer only. Designated channels must first be armed via mouse or keystroke, then the Punch button is used to punch in and out of record. In this respect, the system is much like using a multitrack tape machine. It is also possible to set up auto punch‑in and ‑out points, though I must admit that I've never had need of such a facility.

The faders provide two modes of operation other than Isolate: Absolute and Update. In Absolute mode, the current fader position is recorded, so any moves play back exactly as you made them, and any previously‑recorded fader moves are replaced when you keep the mix pass. In Update mode, however, any previously‑recorded fader moves are modified rather than replaced by the new fader moves. Effectively, the old data is added to the new data (which starts at zero from wherever the current fader position is set), so that small moves of the fader can be used to trim the old data. For example, if the chorus is a couple of dB too quiet, but everything else is fine, you simply go into Update mode on the relevant channels, then push the faders up 2dB from their current position. Users of other automation systems might feel happier with the term Trim mode.

Another feature designed to make life easier is Extend. It may be that you're working on your mix in sections, so to carry on working from where you left off, all you need to do is activate Extend, and Drax will drop into record quite automatically as soon as you get to a section of song that hasn't had any mix data recorded. Hitting the Ctrl and K keys together updates the mix in the base buffer with the new mix data, while pressing Ctrl and U discards the new pass.

The System

The mix data hierarchy of Drax is quite logical, and follows the system of Reels, Titles and Mixes. Reel is where you would enter the name of the physical reel of tape to which your mix data relates, while Title defines a timecode start and end time within that reel, usually corresponding to an individual song. Mix is used to store various mix versions of the title, and though a few software tweaks were still being made at the time of this review, the idea is to allow you to key in a new name for each mix. Alternatively, if you save a mix without naming it, the mix will adopt the same name as its predecessor, but the version number will increase by one. This latter way of working seems the most logical. Once you've defined the start and end limits of a title, you can't extend it, so you should make sure you allow yourself enough room for any future intro or outro extensions before committing yourself.

Though there is only one screen in the Drax software, the keyboard commands and functions change depending on what Keyboard Level is selected. For example, routine mixing is done at the Console level, whereas you set up mix information in the Mix level. The only time the window switches to a new one is if the on‑line help is called up — a most welcome addition. There are also on‑screen prompts with a user‑definable timeout period for dismissing them.

The designers at Optifile feel that most people using computers in the studio don't want to be tied to using the mouse, so they've created a set of straightforward, and largely intuitive, keyboard shortcuts to enable all functions to be controlled directly from the keyboard. However, so that mouse users aren't left out in the cold, conventional menu commands are provided, as well as a number of 'click and happen' points in the fader display window. The final release version will include the ability to toggle between the available fader and mute modes purely by clicking in the appropriate area of the channel strip; in fact, I was told these changes had been made before I'd even finished writing the review!

Impressions Of Drax

As an affordable automation system, Drax offers a friendly yet professional user interface, coupled with a high‑quality signal path courtesy of the dbx VCAs. To my mind, most aspects of the program are actually clearer and more intuitive than on the more upmarket Tetra system. A further benefit is that the high‑resolution PC display is far clearer than Tetra's low‑res TV monitor.

If there's a problem with Drax, it is likely to be one of perception. The basic system costs just over £2000 for 24 channels. The basic Pentium needed to run the Drax software costs under £1000, so for under 3000 pounds in total, you get a fully‑installed 24‑track system with both hard and floppy disk storage, a hi‑resolution colour screen, and mouse control if you want it. However, because the Drax software can't yet run alongside sequencing software on the same PC, it is almost certain to attract criticism from those potential users who simply refuse to have one more computer in their studios. Many simple MIDI‑controlled automation systems will run happily with a sequencer, so some users are bound to ask why Drax can't manage to do the same. After all, a top‑end studio might have the space and budget to accommodate an extra computer, but in the small studio, which is where Drax is obviously aimed, this is a very valid concern. As I said earlier, Optifile are working on new drivers to fix this limitation.

My personal view is that Drax is a very serious system, and should be viewed as a pro automation package with slightly simplified facilities rather than as a cut‑price, semi‑pro alternative. After all, the same VCAs are used here as in Optifile's top‑end Tetra system, and the audio quality is superb. Having the automation display permanently visible is also very appealing, and if you're a mouse user with no spare desk space, you can always use a trackball. Anyone who is considering a Tetra system but can't afford it should jump at the chance to fit a Drax system.