Art Pro VLA
Art Pro VLA

Pro VLA, Studio compressor from Art.

content in English
briank 22/07/2011

Art Pro VLA : Recensione di briank (content in English)

"Sonically interesting, but poor quality"

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This review covers the older ProVLA, not to be confused with the newer ProVLA II.

The ART Pro VLA is a low-cost 2-channel, transformerless, soft-knee opto compressor with a vacuum tube output stage.

The power cord is hard wired, and there are parallel 1/4" TRS and XLR audio connection points for each channel. There are no addition connection points such as sidechains available.

Metering is provided by mechanical VUs as well as multi-segment LEDs.

The chassis is a standard 2U rack-mountable affair.


The ProVLA control interface is fairly simple and straightforward. Each channel has a smooth-feeling rotary pot each for Threshold, compression Ratio variable from 2:1 up to greater than 20:1 limiting, and finally, an Output level trim.

There are also a set of push-button switches that allow you to toggle Attack and Release times between two presets which are, apparently depending on the product run, either "Fast" and "Slow" or "Fast" and "Auto." Mine are the "Auto" variety.

There are also buttons for Bypassing each channel, and another for Stereo Linking the two channels which, when activated, makes Channel 1 a master and Channel 2 a slave for Ratio and Threshold control. Finally, there is a switch for VU i/o metering; however, I would caution that the mechanical VU meters are not calibrated in any way that makes sense to me when set to show input level. Applying a balanced +4dBu input signal will NOT show as 0VU on the mechanical meters and they tend to read a fair bit lower than they ought to be, so take what they tell you with a grain of salt and consider that the VUs are at best a bit eye of candy. There is no option for gain reduction metering with the VUs; instead, there are multi-segment LEDs on the unit for this which are, mercifully, more trustworthy.

The power switch is on the front face rather than on the back of the unit, which I appreciate.


These are sonically interesting, if somewhat limited. One thing I can say about the ProVLAs is that they're smooth operators. Their main job in the compression color spectrum is warm, slow, thickening of sources needing only modest dynamic control. Think of it as "sonic syrup." The ProVLA is capable of "gluing together" a stereo mix buss, and is also good for thickening up digital tracks or thin sounding sources, and for smoothing over harsh transients.

The ProVLA is happiest with smaller gain reductions and sensible ratios. I find that they're best at Ratios between 2: and 4:1; beyond that, the ProVLA can lose its composure pretty quickly and become mushy, pump-y and breath-y in a less than flattering way. Save the higher ratios and hard limiting for a more suitable, more aggressive unit than the ProVLA, but as long as you keep them in their comfort zone--and they're actually working properly--they're good at what they do, sonically speaking.

Purveyors of tube rolling can alter the output character somewhat, but will not change the actual compression characteristics with tubes. The biggest difference in tube rolling is in changing the output gain stage by going between different tube types (12AX7s and 12AT7s, for example) rather than playing around different brands of the same type. My units both came stock with Electro-Harmonix 12AT7s (despite these units being advertised at using 12AX7s) and after playing around with JJ Electronic ECC83Ss, ECC81s, JAN Philips, Sovtek and Ruby (Chinese) 12AX7s and even some old RCAs. I liked the JJ ECC81s, but the differences were too subtle to worry over it very much. I wound up back at the stock E-Hs.


I own two ProVLAs and unfortunately both have been plagued by reliability problems. They have always been racked up, run on quality conditioned power and treated well, so I have concluded that these units are simply poor quality.

One unit failed wholesale after only several months from new; it simply wouldn't power up. I thought perhaps it was a simple matter of an easily replaced fuse blowing, so decided not to bother paying to ship it for warranty repair...but to add insult to injury, the screws holding the top plate on the unit had been grossly overtightened at the factory and wouldn't budge. By this time, I was starting to experience problems with my other unit and decided not to bother dealing with ART, so I went ahead, cut the top off, ascertained that it was not a bad fuse but a more serious failure due to poor parts quality or manufacturing defect. Quite frankly, at this point, I washed my hands of it and ART, boxed it up and saved it to use a modding platform or parts unit so that it wouldn't be a total waste. Ouch. At least I'd gotten in on sale for a really cheap price.

My other unit never failed completely, but has suffered meter failure, all pots are always scratchy and need constant exercising, switches have gone dirty and noisy or failed, channels can experience noise problems, and the audio connections are prone to oxidation. The VU meter lighting, which, like old-school mechanical meters of yore, is provided by incandescent fuse style lamps which are prone to burning out relatively frequently. They have a warm, throwback look to them, but as this is a product of the 2000's rather than the 60's or 70's, I'd have preferred a reliable, low power LED lamp for each VU. On a side note, this would probably be a fairly simple mod to apply for those with a bit of technical skill who are tired of replacing VU lamps.

Of course, I've talked to other people who claim a more trouble-free experience with their units, but I would counter by saying that I bought my units about a year apart; they were NOT part of the same bad production run and were always well treated, so I really did strike out twice.

In the end, you might have a reliable ProVLA or you might not. Personally, I'm not going for "third time lucky" and will never consider another ART product again. Sometimes you do get you pay for. The ProVLAs are capable of dishing up some good sounds when they're happy, but undependable units are useless to me. I would never trust them to critical applications such as live use; they are ultimately cheaply made, cheaply sold, low quality units in my experience.