The prototype of Drawmer's LX2O compressor was first unveiled at the APRS show earlier this year. Both its price and its performance seemed impressive. Read on and find out why.

There are a good many compressors around currently, even at the lower end of the market. However most display some undesirable side-effects unless you're somewhat frugal with the amount of compression applied. The reason for this was concisely outlined in Dr Bateson's review of the Ashly CL52 in H&SR July 86, so I won't go through it all again here. Suffice it to say that the conventional selectable ratio compressor that we all know and love will always suffer from a dulling of transient sounds unless some pretty elaborate processing tricks are employed and that would automatically takes us out of the semi-pro price bracket. What Mr Ivor Drawmer has done in order to side-step this problem is to use a so called 'soft-knee' circuit, rather like the DBX Over-Easy system, where the compression ratio is not fixed but starts off low and increases with input level. On this model he has also included a very effective expander gate which keeps the noise down during pauses: a most valuable addition and one that's becoming more and more standard as new compressors come onto the market. Again the logic behind this has been thoroughly covered in preceding issues but in a nutshell, any ordinary compressor will interpret periods of silence as low level signals that need turning up and so it will apply full gain resulting in an increase in any residual noise. By including an expander with a variable threshold, the system can be made to shut down when the input signal falls to a level approaching that of the background noise and the resulting output is much quieter. Theory aside, let's see what we get in terms of hardware.

First Glance

Drawmer's enviable reputation was built on their noise gates which I believe were the first to be built with integral sidechain filters. The LX20 follows a similar physical format in that it occupies the now almost obligatory 1U rack case and consists of two channels that can be used either independently or as a tracking stereo pair. Furthermore, the operating level may be set to +4 or -10dB simply by swapping over a pluggable link under the cover.

The styling is commensurate with other products in the Drawmer range and the standard of engineering is high following a simple and robust approach with no unnecessary frills.

Both the inputs and outputs are on unbalanced jacks, partly I suspect as a cost saver and partly due to the fact that line level signals running from the desk to the effects rack seldom suffer any problems in their unbalanced form. Also many smaller studios use unbalanced patchbays, so balancing would be no advantage to them. Supplementing the input and output connections are two more sockets, one a stereo jack offering insert access to the side-chain and the other a Mute jack. This enables the user to mute the output using a remote (normally-open contacts type) switch but more usefully, it may be patched into an automatic mixing system or Drawmer's own M401 MIDman MIDI management unit to provide synced muting. This feature is also compatible with the Drawmer T102, a counter add-on designed to complement the gates.

Moving round the front, the control implementation is ergonomically laid out and offers a good deal of flexibility without unnecessary complexity. The first control from the left is a simple threshold control for the expander section. The gate has a fixed fast attack and a release time which depends to some extent on the setting of the compressor release time. This is designed to keep its operation unobtrusive on the majority of signal sources by making the expander release time appropriate to the compressor release time. A red LED indicates whether the expander gate is open or closed and its wide range (-50dB to +20dB) will accommodate virtually any signal.

Moving to the compressor section, the control set-up looks a little unconventional in that there's an Attack control, a Release control and an Output Gain, but the only other control, is simply called Compress. There's no ratio and no threshold. That's because of all this soft knee business. There is no sharply defined threshold; the larger the signal gets, the more compression is applied. It's as simple as that. And that's where Compress comes in, it allows the user to set up the severity of the compression with a single control. As far as the other controls are concerned, Attack offers a range of 0.1 to 5mS and Release is from 0.1 to 5S.

The only additional features are the ones that you'd expect: a Bypass switch for each channel and a Stereo Link for those occasions when you want to compress a stereo signal rather than two mono ones. In the stereo mode, the control operation is a little unconventional in that both sets of controls are still operative. The control circuit uses an averaging system giving the best compromise between image shift and one channel punching holes in the other when the two channels are radically different. This arrangement was pioneered on the original gates and has worked out very well in practice. However, the mutes remain independent even in the stereo link mode so they must be switched simultaneously or left unused. In any event, it's unlikely that anyone would need to use the muting on a composite stereo signal.

The mains switch, lead and fuse we'll take for granted but it is worth mentioning that the electrical constructional standards are in accordance with VDE recommendations. You may also like to know that the chassis is earthed but that the signal ground is connected via a ground lift resistor so earth loops shouldn't be a problem.

The display on any piece of equipment can make all the difference as to whether it's easy to use or a real pain. Fortunately Drawmer have done us proud in this department by fitting an 8-section LED readout showing the amount of gain reduction being applied. A further red LED indicates that the remote mute is being operated and finally, a 3-section traffic light (red, yellow and green LEDs) monitors the output level on each channel. Even the Link switch has a red status LED so you'll know when you've selected it, very important when you consider that most effects racks are positioned too far away to see individual switches clearly.

In Action

After all this build-up, you'll want to know how well it works. Basically, I'm very impressed. The soft-knee approach has dramatically improved the transient behaviour in comparison to more conventional designs and even whole mixes sound good. Most compressors will sound passable on an individual voice or whatever, but few will sound as good on a complete stereo mix as this one does. It adds a lot of punch and makes the whole thing sound more gutsy without making it muddy. There's no appreciable loss of brightness, even at high levels of compression, and the fact that there are controls for Attack and Release, unlike some soft-knee compressors, means that you can be creative and tailor the compressor's response to individual sounds when you are processing separate tracks within a mix.

Because compressing signals, particularly off tape, introduces unwanted noise, the expanders are a Godsend. Though of little practical use on complete mixes, these operate well on single tracks and when used on vocals, open and close between words and phrases with the required speed. As with any gating system, you have to take care to get the threshold level dead right but that is just a matter of listening and twiddling until you're happy with the result.

The Mute system works as you'd expect without introducing unwanted clicks and bangs but I didn't have an automated system to really go to town with it. Still, any limitations will be those of the controlling system and not of the LX20 as the LX20 simply does as it is told by the external switch.

Conclusions

Without taking price into consideration, this compressor puts in a very impressive performance. It can be used to control, modify or fatten virtually any signal and it's very good at making the output sound 'unprocessed' if you want unobtrusive level control as is often the case. It's not as transparent as the special 1st Aphex Dominator and Compellor, but then it only costs about the same as the VAT on those!

By using a ridiculous amount of compression on a complete mix, you can get that really ballsy 60s sound, great for R&B, and even then pumping isn't that noticeable.

It sounds wonderful doesn't it, but how are you going to able to afford anything that works this well? Well, you may be in for a surprise when you hear that the whole thing is only £225 plus VAT. It therefore represents one of the cheapest professional quality compressors on the market and what's more, your money will be going into the British economy and not into some Japanese Megacompany. The last word is that I'm going to get one and yes, I do have to pay for it, but at that price, who's complaining?

The Drawmer LX20 compressor costs £258.75 including VAT.

Further information can be obtained from: Drawmer Distribution Ltd, (Contact Details).