ART Dual Levelar

Richard Waghorn takes ART's new electro‑optical compressor into the studio and is genuinely surprised at the results.

Of all dynamic control devices, compressors tend to invoke the most emotion amongst users, due to their ability to impart certain tonal characteristics as well as controlling dynamic range. In today's studio the compressor is as much a creative device as a corrective one. There's a wide range of units to choose from, with various models using both solid‑state and valve technology to process individual tracks of vocals and instruments, or apply dynamic stereo control to an entire mix. Some manufacturers add other dynamic control tools, such as expander gates, limiters and side‑chain filters, to extend the flexibility of their products, but with the Dual Levelar ART have taken a more simplistic approach. This is a very easy‑to‑use, straightforward, dual‑channel compressor using an optical‑type gain‑control element, plus valve circuitry, with the aim of delivering a classic retro sound.

One cannot deny the popularity of early optical‑type compressors; the UREI LA2 springs to mind — and, of course, there are also the newer Joe Meek designs. ART have used a similar electro‑optical design philosophy to recreate the sound of those classic tube limiters, by using a Vactrol‑based levelling amplifier, plus valves in each channel, instead of the more common VCAs and transistors.

The Dual Levelar comes in a 1U, all‑steel rackmount package with an internal power supply, switched from the front panel. All signal input and output connections are made on the rear panel using either balanced quarter‑inch jack sockets (TRS configuration, tip hot) or XLRs (pin 2 hot). The inputs are designed for line levels ranging from ‑30dBm to +15dBm and will happily accept unbalanced quarter‑inch jacks. Although, obviously, you cannot use both inputs simultaneously, both outputs can be used at the same time to split the output, should this be desirable.

Controls

Each channel has just two control knobs and three buttons. Threshold sets the point at which the gain control circuit starts to operate — turning the threshold down increases the amount of compression; turning it fully clockwise allows the signal to pass unrestricted. Next come three switches, the first of which is a bypass, followed by what ART call a Limit/Comp button, which switches between mild and heavy compression ratios. Finally, the Auto/Fast switch controls release characteristics. The remaining control knob provides make‑up gain to bring the compressed signal back up to line level. The Dual Levelar is also fitted with a stereo link switch which forces both channels to track together when the compressor is being used on stereo material. In stereo linked mode, both channels are operated from the left‑hand controls, except for the output gain.

I enjoyed using the unit so much that I might just have to buy one — I was that impressed!

Each channel features a four‑LED gain reduction meter to provide a visual indication of how much compression is taking place. The first LED flashes when the input level reaches the set threshold. The remaining three illuminate at ‑3dB, ‑6dB and ‑12dB respectively.

In Use

I found the Dual Levelar very easy to set up; after all, there's not much to play with! When the power is switched on, all the LEDs light up and stay on until the valves have warmed up; the unit is ready for use once the LEDs have switched themselves off. ART recommend that two to three minutes should be allowed before a consistent result can be obtained.

The compression ratio can be switched between (Comp) 2.3:1 and (Limit) 6:1. This means, for instance, that in the Comp position, with every 2.3dB input signal rise over the threshold, the output will be reduced by 1dB. The manual doesn't make it clear whether this is a soft‑ or hard‑knee compressor, but to my ears it has the smoothness of a soft‑knee model.

I've always liked the sound of optical‑type compressors — there's something about this kind of circuit design that makes the compression sound more musical.

The release time can be set to Fast (200ms) or Auto, the latter allowing the Dual Levelar to adjust itself depending on the dynamics of the signal being processed (program dependent). As a rule of thumb I would start by trying the Fast setting on signals such as drums or vocals and the Auto setting on whole mixes, although interesting effects can be achieved by experimenting with the options. In fact this compressor was surprisingly effective with every type of input I tried, giving drums a particularly solid, fat sound without noticeably affecting attack or dynamic power. When I used the Dual Levelar on a lead vocal it gave the sound presence and definition without any glitches or noticeable spikes on 's' and 't' sounds. Without changing the overall character of the sound, it enabled the vocal to sit more evenly in the mix. I wouldn't normally expect this kind of smoothness and warmth from a compressor in this price bracket. When pressed into action with a whole mix it also performed well, with no unacceptable pumping or squashing of the music. It was also fairly well disposed towards transient material, though heavy compression eventually results in some suppression of detail.

Overall, the sonic quality of this unit is transparent, yet undeniably flattering. I found the sound of the compressed signal very pleasing, particularly the integrity at the top end; what I didn't like was the fact that in stereo‑linked mode the output was still separately adjusted on each channel. Some might also miss the inclusion of a side‑chain insert point to allow the use of an external equaliser for de‑essing and frequency‑conscious operations.

Conclusion

The Dual Levelar is definitely not an all‑singing, all‑dancing dynamics processor, but what it does do it does extremely effectively, with a claimed dynamic range greater than 105dBm. It's simple to set up and the ratios are well chosen for most applications, as are the release times. In fact, I enjoyed using the unit so much that I might just have to buy one — I was that impressed!

I've always liked the sound of the UREI LA2 and optical‑type compressors — there's something about this kind of circuit design that makes the compression sound more musical. I'm not claiming that the ART Dual Levelar competes with the likes of Tube‑Tech or Summit, but for £299 this is a good‑quality, very nice‑sounding, no‑nonsense compressor. If you're in the market for a new dynamics processor, record some drums and vocals onto a DAT or cassette tape and try out the Dual Levelar at your local dealer.