New Gear Review: elysia MPressor 500

View Single Page

Elysia has made efficient use of the limited real estate on the faceplate of the MPressor 500.

At the AES convention a few months ago, I found myself passing by the elysia booth, and considering how eye-catching their wares are, I just had to see what was new.

Among their latest offerings was a new 500 series version of their 2U rackmounted MPressor which debuted in 2007, and more recently, spawned a software emulation from Plugin Alliance. Already a fan of their forward-thinking designs, I had to get my hands on one.

There are tons of compressor options available nowadays, both hardware and software. Sonic differences aside, most of them offer a number of similar parameters, and it is rare to find a unit with controls I don’t recognize. But elysia is a company not content with sticking to the tried and true. They even go as far as to tout the MPressor as being “The compressor from the future.”


The MPressor 500 differs from not only from other compressors, but also from the 19” rack and plugin versions that bear its name.

All three versions provide the standard Attack, Release, Threshold and Gain controls, as well as the very interesting additions of an “Auto Fast” attack setting, an “Anti-Log” release setting, and a maximum reduction control, abbreviated as “GRL” on the 500 series unit—short for “Gain Reduction Limit.”

While the smaller faceplate of the 500 series format necessitated the removal of the EQ controls found on the larger unit, elysia makes up for this by adding a “THD Boost,” delivering even more tonal options.

Opening the box, the first thing I noticed was that the unit felt light, even by 500 series standards. Weight aside however, it did not feel poorly made by any stretch. In fact, the knobs and buttons feel very solid and sit on what I think is a very attractive faceplate design. Installation was a breeze, like with most 500 format units, so I had signal running through it quickly.

In Use

I first used the MPressor 500 on electric bass, something to which I usually apply a healthy amount of compression. Even before adjusting the threshold, I noticed a fullness to the sound of the unit.

A clockwise turn lowers the threshold, thus applying more gain reduction. The resulting compressed signal was not exaggerated or tubby-sounding, and had a full midrange that was solid in the low mids. This made the MPressor a great choice for this particular bass, which was funky, but with a bit of a scooped frequency response.

The slaps and pops from that funkiness required a fast attack time, and the MPressor is fully equipped for this. The standard range of attack goes from 0.01 – 180 ms, and engaging “Auto Fast” provides additional control.

This Auto Fast function shortens the compressor’s attack time automatically on faster, louder signals. This allows you to set a longer overall attack time and still catch the occasional excessive transient. This could be great for a snare track with a lot of ghost notes for instance, really clamping down on the main hits while allowing the quieter ones more room to breathe.

The “THD Boost” is a nice tonal option, and its implementation is very clever: Switching it on boosts the level before the gain control element, adding harmonics. The gain reduction circuit runs in parallel however, so it is not affected by the boost. Instead, the saturated signal is compressed, but the detection is based off of the original dynamics.

Aside from the standard Threshold, Attack, Release and Ratio controls found on compressors, Elysia has managed to fit some powerful tone-shaping controls such as “GRL”, “Anti-Log”, “Auto Fast” and “THD” boost into the compact footprint of the MPressor 500.

The Gain Reduction Limiter is another example of creative thinking, acting as a variable threshold for the compression circuit itself. It sets a maximum compression amount, so no matter how loud the input gets, the MPressor will only compress up to this amount. This is a great tool for allowing loud passages to still retain some of their dynamics.

I found it particularly useful for vocals. With GRL engaged, the loud sections stayed controlled without sounding choked or over-compressed. elysia may not have invented this idea (think of the Range control on the Waves C6 for instance), but it is a very welcome and still-unusual feature.

Along with these new features, elysia also expands on some traditional parameters. The ratio controls include negative ratio values, which reduce the signal not just to the level of the threshold, but below it.

The MPressor also provides more release options with the Anti-Log circuit. Switching this in makes the unit’s release faster as the input level declines. Each (or both) of these parameters can lead to some serious grooving and pumping, and if they’re doing too much, you can use the GRL to rein them in.

To Be Critical

There wasn’t much I didn’t like about the Mpressor. Honestly, I really didn’t want to send it back. I can say however, since the unit definitely does have a sound, it might not be right for everything. It sounded a bit thick on certain vocals. While the MPressor is incredibly versatile in operation, it is definitely a “character” compressor, which is less of a flaw than a design choice in my opinion.

Summing it Up

Vintage designs capture a great deal of attention in the marketplace, and rightfully so—they contributed to the sound of the records we all fell in love with when we were younger. However, when they were new, those same vintage designs were actually at the cutting edge, and we need companies like elysia to push the envelope so we can have future classics.

I found each of the non-standard features in the MPressor 500 to be interesting, and most importantly, useful, making this great-sounding unit more than “just another compressor.” At $750 it is an affordable and unique addition to your hardware dynamics collection.

Paul “Willie Green” Womack is a Producer/Engineer based in Brooklyn, NY. Working primarily in Hip-Hop, R&B and Gospel, his credits feature artists including Donnie McClurkin, Wiz Khalifa, Open Mike Eagle, Billy Woods and many more.

Comments are closed.