ART: SOLO VLA Compressor

I’ve been a longtime user of Applied Research and Technology (ART) hardware, as have most of my engineer friends with home, project, and professional studios. I remember many of my early-2000s era recordings being tracked and mixed through my old Dual Levelar compressor, mastering projects going through the original PRO VLA compressor [Tape Op #37] (I use this unit regularly), and a friend of mine still has on permanent loan my old TPS II dual channel mic pre. Suffice it to say, ART and I have some history.

Enter the Solo VLA compressor, one of three of ART's new Solo Series products that also includes the Solo MPA tube preamp, and the Solo Studio channel strip. The ART Solo VLA is a single rack space, single-channel, multi-voiced tube opto compressor with some cool tricks up its sleeve. According to the company’s documentation, the unit offers a studio-quality audio signal path consisting of a hand-selected 12AT7 tube. Further review of the spec sheet backs up these claims with some impressive stats: 20 Hz to 80 kHz frequency response, dynamic range of greater than 100 dB from 20 to 20 kHz, and less than 0.02% THD. Input noise is also impressively low. XLR and 1/4-inch balanced connectors are provided for inputs and outputs, with +4 dBu and -10 dBv level selection via a push button on the back of the unit. The front panel is laid out logically, featuring the standard controls you’d expect on a compressor: Threshold, Ratio, Attack, Release, and Output.

The unit is built robustly, with solid knobs that give satisfying resistance when adjusted. Said adjustment for each knob is via detented potentiometers; excellent for recall and mixing/mastering. What really sets this unit apart from other ART compressors I’ve used in the past is the ART Solo VLA's ability to switch between two distinctly different compression modes: OPTO (optical) or FET. I’d never used or heard of any ART FET compressor, so this was exciting [The discontinued ART TransY preceded the Solo VLA. -Ed.] In addition, there is a Blend knob that allows for parallel compression, plus a Bypass switch, and a small but usable built-in VU meter. All this adds up to a seemingly impressive unit, with some useful and thoughtful touches, but how does it sound?

I have an Avenson STO-2 omnidirectional mic that I wanted to use as a mono drum overhead for this review, set up about five feet above the center of the drum kit through a transparent-sounding mic pre. I've found that this combination reveals nearly every detail of a drum kit’s sound interacting with the tracking room's character, for better or worse. Often, this setup is rather unflattering in its real-world representation. In this instance, compression used inline during tracking greatly enhanced every element, elevating not just the sound but also the feel of the performance. Patching in the ART Solo VLA to the signal chain, and selecting FET voice option, I quickly found some settings that enhanced the sound of the drums but didn’t distort the accuracy of their sound. I set the Threshold to catch the louder hits and adjusted the Ratio to approximately 4:1. The Attack was left at a medium setting, with a slow Release to allow the tail of the snare and cymbals to breathe. Whenever it started to sound too constricted or too slammed, I’d dial back the compression amount on the Blend knob just a bit to introduce more of the original signal. I wish every single compressor and limiter ever made had this feature – it is awesome! With a bit more fiddling, I eventually found a happy balance to track with. Tracking through the ART Solo VLA, the kick drum seemed bigger and punchier, cymbals were under control but not strangled, the snare popped out of the mix and had elements of that papery sound I’m always trying to get, while transients remained intact and had a bit of that focused punch typically associated with vintage Urie 1176-style compression. Overall, my impression was that I would really like to try out four or more of these units on a full multi-mic drum session, as I believe extending the polished yet raw sound that I was getting with a single overhead mic would be enhanced with the additional mics and compressors, and the control they would afford.

With a usable mono drum track in Pro Tools, I created a few extra tracks and sent what I had just recorded out of my interface back into the ART Solo VLA to see how I might use it on a mix. The Output of the unit provided the makeup gain needed with my passive summing device without imparting any real noise floor elements into the sound. That said, I do wish there was an input gain on the ART Solo VLA, as I think it could aid in achieving a bit more character. Despite this, the unit did not disappoint. FET mode will get you there when you need a bit of aggression. It’s fast, punchy, and can add hints of harmonic distortion that’s ideal for more in-your-face elements. It worked very well at getting a slammed drum room track to duck in under the original mono recording while beefing it up and adding an overall bigness to the room sound, especially on the cymbals.

With an overly impressive sound for the simplicity of drum tracks I had going on now, I decided to track some DI bass through an external pre with optical mode selected on the ART Solo VLA. The ART delivered that classic, smooth compression in the style of a Universal Audio LA-2A [Tape Op #26]. It has a way of gluing the elements of the playing with a musicality while ensuring the pick attack was never over the top and always smooth, resulting in a bass tone that was almost more felt than heard when playing back through the monitors. Optical mode also seemed to round off the transients without losing the natural dynamics of the performance. However, when I flipped to FET mode, the bass came alive with a presence that cut through the mix, really fitting well on top of the drums but without being overbearing. The Blend knob allowed me to dial in just enough compression to keep the bass consistent without choking the dynamics.

Like so many ART brand products that have come before it, the ART Solo VLA is a versatile compressor punching well above its weight, even if it were double its diminutive price. The unit is clearly designed to compete (and win!) in the entry-level dynamics market. The versatility of two different compression modes offers a wide range of sonic possibilities, from smooth and musical to fast and punchy. I’m looking forward to a possible MK II version that adds input gain, a sidechain high-pass filter, and the ability to stereo-link a pair of units together. Granted, this would probably up the price, but I think many wouldn’t mind shelling out a few more clams with those features added. As it stands, for situations where you need reliable, versatile, high-quality compression without breaking the bank, the ART Solo VLA delivers.