“Lunchbox”: 500 Series Compressor: RoundUp: Squeeze Your Sound By Squeezing These Into Your Lunchbox

As Jay Matheson noted in his 500 Series Pre Amp Roundup on page 54, there are a variety of advantages with the “API Lunchbox” format— and this format’s popularity among engineers is rising. Consequently, we’ve seen a swell of offerings in the 500 series compressor field. We were fortunate enough to obtain almost every available model for our roundup, and even more fortunately, the gang at Mercenary Audio loaned us a six-space API model to house them. Later, Purple Audio let us enjoy one of their Sweet Ten rack units. For more information about these boxes (as well as some other options), see the sidebar on page 64; note that all prices given are list prices.

SQUASHING 1-2-3-500

In addition to the other engineers at Treelady Studios, I enlisted the help of Herman “Soy Sos” Pear, from Tuff Sound Studio. Soy normally focuses on electronic, urban, and world music, and he brought an extensive collection of modular synthesizer sounds that ranged from spacey to phat to downright bizarre. We also used guitar, piano, bass, and drum source and submix tracks from country singer Christian Trich, progressive rockers Undermine the Common, and rapper E Rock. This provided us with a wide range of instruments, vocal styles, and production aesthetics for our tests.


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PRICE: $675
STRENGTHS: All-button in “Nuke” Setting. Tri-color LED metering. Everyday workhorse compressor performs well on most sources.
LIMITATIONS: Extreme settings can cause distortion. Ratio knobs can be difficult to move. Dialing up good sounds on some sources requires patience.
CONTACT: www.purpleaudio.com

While most of the other units gave us immediate gratification, we had to work with the Action. This is not bad; some of my favorite gear required time to get used to the control interactions. Soy Sos found Action outstanding for tracking samples and fast transient synth materials, but he had difficulty dialing in vocal settings quickly.

Purple states that the Action is reminiscent of their MC77 (a respected recreation of the Urei 1176; Purple was the world’s only source of this particular compressor sound for several years). I can see the relation, but at the same time, this is not an MC77 packed into a 500 series rack. For one thing, the attack and release times are much broader than the MC77, which can cause distortion if you’re not careful. We wanted to like the Action on bass, but our results were average. However, on synth samples, kick drum, and snare, the Action came alive, adding pop, snap, and presence to sources. The more we used this box, the more we liked it.


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PRICE: $995
STRENGTHS: One knob operation. True hardwire bypass. Independent limiter. Gain makeup.
LIMITATIONS: Requires the right input for proper gain staging. Meter less useful than standard VU.
CONTACT: www.burginmcdaniel.com

Talk about vibe: The Komit comes in an Army issue ammo box, has G.I. Joe green-rubber knobs, and a level meter that looks like the control panel from a missile silo. The guys didn’t like the meter, but I did—it fits with the unit’s personality. Instead of ratios, there is a compress knob that has images of a circle that gets more squashed and pancake-like as you go clockwise. But don’t think this is all sizzle and no steak. Both Kevin Burgin and Travis McDaniel have years of audio and tech work on their résumés, including working side-by-side with Mr. Rupert Neve.

The Komit is a feed-forward compressor and limiter. Simply set the level, choose one of three presets (fast, med, slow), pick a compression level, and you’re ready to go. However, note that the Komit requires a reasonably hot signal for best results, so be prepared to drive this box hard—but that’s expected, because this is a macho compressor. You know the type: just a man, some coffee, slab of bacon, a six-shooter, and his horse.

In fact if John Wayne were a compressor, he would have been the Komit: “Look guitars, I need you to plunk yourselves right here in the mix and stay there!” I would describe the sonics as vintage, thick, Neve-esque, rich, and slightly aggressive; it’s great on guitars, bass, backing vocals, synths, and drums (individual or bus). The Komit is not as clean or hi-fi sounding as the AnaMod, but it doesn’t want to be. If you work with rock and roll, you want a Komit. Or two.


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PRICE: $1,150
STRENGTHS: Mix feature. Sidechain ability. RTR can sound like a pro riding the fader. Could be your next go-to vocal compressor.
LIMITATIONS: Takes up two spaces. Not as “warm” as the Essence. Lowest ratio 3:1.
CONTACT: www.buzzaudio.com

Like the Essence, the Potion requires two spaces in the 500 chassis, and offers the same sidechain and linking powers. The Potion uses a Field Effect Transistor (FET) gain reduction element, which sounds completely different from the Essence. I would describe it as being more forceful, but not in a harsh way. Other differences include unique ratios of 3, 7, 10, and 20 to 1, a Release Time Reduction (RTR) setting that automatically changes the release depending on the attack depth, and a mix knob, that allows you to blend the uncompressed source with the compressed signal for true parallel compression effects.

The Potion was solid on instruments, especially guitars and bass. Having the mix option made all the difference. Remember those unruly bass and synth tracks? They were no problem for the Potion. We just selected its super-fast 50 microsecond attack and a 10:1 ratio, then blended this in until we had a sound that was in control without having that dehydrated, fatiguing sound. Kick drum or snare sticking out too far? Just add an equalizer to the side chain and tell those kids to have a seat. But save room for vocals with this box, because the Potion is great regardless of genre. We tried rock, country, and rap tracks. A 3:1 setting with the proper mix percentage and the Potion can make the vocalist sound like those old pros who knew how to work a mic.


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PRICE: $485
STRENGTHS: Great bang for the buck. Nice leveling with moderate uses, but also capable of serious sound destruction.
LIMITATIONS: DI does not override XLR input. Aggressive sound not appropriate for every source. No metering.
CONTACT: www.standard-audio.com

The Standard Audio Level-Or is a JFET limiter/distortion processor inspired by the Shure Level-Loc PA limiter. It has two modes: Level and Crunch. Set to “Level,” the unit behaves similarly to the Level-Loc. However, Standard Audio has added an additional, faster release time for even more flexibility. The insides feature some beefy transformers, and the sound, although raw, caused one listener to dub the Level-Or as the “Poor man’s LA-2A.” I could certainly agree with that assessment, especially on bass and some vocal tracks. On a whim, when we pulled up a piano track from a country session for Christian Trich, the Level-Or destroyed the keys in a fashion that mirrored the destruction in the singer’s story. Really cool.

In “Crunch” mode, the Level-Or can start from slight harmonic enhancement, but quickly moves to aggressive crunch, to distortion, to complete and utter destruction of the original source material. Think of a Big Muff or a Pro Co Rat in a 500 series module and you have the idea. Users can take advantage of the 1/4-inch jack on the front, which is line level and parallels the rear XLR jack, to plug in devices like samplers and drum machines without having to deal with 1/4-inch-to- XLR adapters.

All in all, this does some cool leveling and destruction. It’s not a piece for everyday use, but at this price, a pair could really round out a studio’s effect collection.


Users interested in the 500 Series format have more options than ever when it comes to finding a home for their electro-critters; following are three of the more popular chassis on the market.

This is where the lunch box got its name, because, well, it looks like a lunch box. The API unit can accept six modules and has an internal power supply; a standard IEC cable and some modules are all you need. Several vendors sell this unit, but Mercenary Audio will supply you with blank panels to cover any unfilled slots you may have. Even better, if you return the panel to Mercenary they’ll credit you $50 towards the purchase of a new 500 series module.
Price: $425
Contact: www.mercenary.com

For users who want even more portability than the six-space lunchbox, the Revolver—a two-slot 500 series rack— is a great solution. Like the other cases, it’s self powered (and can provide up to five times more than the API minimum power specification). You can configure it in multiple ways; as a stand-alone unit, it can be positioned vertically or set up horizontally for standard 19" rack mounting.
Price: $400 (less when purchased with modules)
Contact: www.atlasproaudio.com

In addition to being an internally-powered rack, the Sweet Ten has several unique features. As the name implies, up to ten units can be loaded into the chassis. However, slot 9 is a special slot that is designed to accept Purple’s Moiyn 8x2 mixer module. The Moiyn effectively turns the Sweet Ten into an 8x2 summing mixer. So, in addition to tracking with modules, you can add equalizers, compressors, or other devices at mixdown. The Sweet Ten can also accept the Purple Audio Cans headphone amplifier, making this a viable replacement for a small format mixer. Around the back, you’ll notice a third XLR row. The second XLR out on each channel provides the option of running modules split, or linked to one another. Our sample unit came with some six-inch long XLR cables that make linking two units a snap.
Price: $800
Contact: www.purpleaudio.com

Other options from API and A-Designs are also available, so evaluate your usage scenario and choose accordingly.


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PRICE: $650
STRENGTHS: Natural-sounding. Key listen makes it easy to target problem areas quickly.
LIMITATIONS: Takes some time getting used to the modes. I want a stereo one for mastering.
CONTACT: www.empiricallabs.com

So many people loved the frequency-dependent compression section on the Lil Freq EQ that Empirical Labs brought out the DerrEsser, a 500 series de-esser. They call it a multi-function dynamic filtering device—I call it cool as heck. Using a band-split approach, high frequencies are separated from lows, which allows the VCA to compress sibilant or harsh transients.

There are actually four DerrEsser modes. With DS, where the level of the highs does not affect the compression, the detector compares the high to the lows; overall signal does not matter. When there are enough highs compared to the threshold, the compression clamps down. In HF Limit Mode, the unit becomes a high frequency limiter, ignoring the low end altogether (this is similar to the Lil-Freq function). In Highpass, you can listen to the high frequencies being controlled with the compressor. And in Lowpass, you can audition the low frequencies being ignored by the compressor. These extra modes help you target problem frequencies, which makes it easier to throw out the bathwater but not the baby.

In use, this has the same clean, quiet, unobtrusive sound associated with other gear from Empirical Labs. I’ve never heard another analog de-esser that works this fast, is this easy to set, and sounds this smooth. As someone who has used nearly every de-essing plug-in I can say this: Save your money, get a DerrEsser.


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PRICE: $1,150
STRENGTHS: Useful auto mode. Dedicated side chain. Clear metering. Gives tracks that million-dollar studio sound.
LIMITATIONS: Takes up two spaces. Not necessarily the best on every source, but I wouldn’t kick it out of the rack for eating crackers.
CONTACT: www.buzzaudio.com

Occupying two spaces in the 500 chassis, the Essence is a differential opto compressor. But unlike some widebodies, the Buzz doesn’t waste the rear XLR jacks. The first set provides input and output, while the second can be used as a side chain. A pair of Essence units can be linked for stereo work. The unit is sturdy, with full-sized control knobs, excellent metering, and premium construction.

The Essence handled anything we threw at it, but really stood out as a bus compressor. On rock drums it provided the good kind of glue, thwack, and round woody tone that makes vinyl aficionados drool. On bass it could clamp down on string noise, or help stretch out sweet sustain. I tend to dismiss any “auto” compression setting, but the auto attack and release modes on the essence seem to have an alien intelligence: For instance, auto can release fast transients while imposing a longer release time on more continuous signals. The overall fidelity of both Buzz compressors was among the best in the group. I would have no reservations using a pair of these on a mastering job, especially for a rock project.


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PRICE: $1,295
STRENGTHS: Most audiophile-sounding compressor in the group. You have to try hard to make it sound bad. Adds a smooth, buttery layer to drums, bass, and guitars.
LIMITATIONS: Slight changes in knob rotation can lead to big changes in sound. Pricey.
CONTACT: www.anamodaudio.com

While the current rage seems to be digital models of vintage gear, Dave Amels and Greg Gualtieri are making analog models. That’s right, modeling gear with gear. The AM660 is the duo’s stab at recreating the Fairchild 660 limiter. From the kidney bean VU meter to the retro-looking knobs, this guy looks like someone zapped a Fairchild with the shrink ray. Controls include input gain, threshold, and eight preset attack/release combinations called “Time Constant.” A bypass button allows for quick before and after comparisons.

The AM660 possesses a very hi-fi sound and gave excellent results on nearly anything we ran through it—provided we spent the time to choose an appropriate time constant. It was also one of the only units that could tame some of the weird square wave synth patches Soy Sos brought. It was a standout on electric bass, especially when the player had extreme jumps in volume. (I believe someone called it the “last word on bass compression.”) Unless pushed, the AM660 didn’t sound like it was compressing, which I found most impressive. If funds permit, a pair of these could take your recordings (and your career) places.


I want to thank Kyle Smith, Dave Hidek, Dom Misja, and Soy Sos for their help with this roundup. And again, a special thanks to Mercenary Audio for the lunchbox loaner. But most of all, I want to commend the manufacturers on creating such unique and well-crafted products. Depending on your production needs, I would have no reservations about recommending these units: They might come in a small package, but they all pack a wallop of sound.