elysia's mpressor is a state of the art two channel compressordesigned to provide the user with both potent classical dynamics processing capabilities as well as unconventional tools to produce thick and punchy sounds not possible on other devices.
 
Engineered for creative bus and track mixing, the mpressor was created for professional engineers looking for something a little different from the standard compressor unit. The mpressor features typical compressor controls such as attack, release, threshold, and gain, but also includes a number of innovative custom analog circuits to provide a truly astonishing level of control over input signals.
A unique frequency filter situated before the compressor, called the Niveau Filter, simultaneously boosts one end of the spectrum while attenuating the opposite, while the auto fast circuit automatically adjusts attack time based directly on signal impulses of the input. A convenient sidechain circuit is included that permits modulation of the compression circuit by directly changing the control voltages. Compression ratios that stretch into the negative values (allowing for extreme "destruction" of input signals), an extremely wide frequency response, a built-in temperature stabilizing technology, and an innovative limiter placed directly in the control circuit are just a few of the impressive and unorthodox features that make the mpressor one of the most flexible rack-mounted compressors available.

Powerful Dynamic ControlGain Reduction Limiter
Rather than being placed directly in the signal path like most limiters, the mpressor's distinct gain reduction limiter is placed in the unit's control path. When activated, the GR limit control knob will directly modify the control voltages of the compressor allowing interesting effects, such as ducking or upward compression, to be achieved without sacrificing the dynamics of loud sections.
 
Negative Compression Ratios
Unlike most compressors, the mpressor can access negative ratios, which lower the output signal as the input signal increases. This is perfect for creating powerful and inventive compression effects, which become more controllable when paired with the gain reduction circuit.
 
Auto Fast
One of the most useful features of the mpressor is the auto fast circuit, which helps regulate attack dynamics. While most compressors require a user to dial in a static attack speed based upon the overall dynamics of a track or mix, the auto fast can automatically adjust the attack speed based directly on the impulse signal, becoming faster and louder with corresponding impulse transients without any manual adjustment required.
 
Anti Log
The anti log circuit allows the user to change the release compression scheme from linear to antilogarithmic. A useful resource for when creative compression or unconventional sounds are desired, this function results in a longer release time when the compression threshold is first passed and shortens when the input signal begins to decline, the opposite of standard compression behavior. This process is independent of the signal gain reduction, producing the same curve at the start of compression regardless of gain reduction.
 
Niveau Audio Filter
The special Niveau audio filter is the perfect tool for when a shelving EQ would be limiting and a parametric EQ would be too complex. This filter works by simultaneously reducing one end of the frequency spectrum while attenuating the opposite end, much like a pair of scales. This makes it much easier to influence the character of the signal and the center frequency can be shifted continuously between 26 Hz and 2.2 kHz or (with x10 button activated) 260 Hz to 22 kHz. Through the EQ gain controller, the filter can be pushed into a pure low-pass filter at fully counter-clockwise, while turning fully clockwise will transform it into a pure high-pass filter.
 
External Sidechain
Through the external sidechain inputs, the compression level can be triggered directly by an external audio source that is not part of the audible signal chain. A duplicate of the input signal can be combined with external EQ to engage frequency-dependent compression or percussive sounds such as a bass drum can be used to trigger pumping compression that is synchronized with the music.

Engineering Sophisticated Creativity Dynamic Analog LED Meter
While most meters for judging gain reduction lack real-time accuracy due to needle inertia or abrupt value changes in LEDs, the mpressor solves this limitation with a special analog circuit that dynamically adjusts to the signal with incredible precision. Rather than simply flickering on or off, the LED meter utilizes its purpose-built driver to display intermediate values by modulating the brightness of the LEDs, ensuring smooth and obvious transitions from one value to the next.
 
Discrete Class-A Topology
The entire mpressor circuit board is built with custom-designed discrete components. This includes the full audio path, sidechain, power supply, and even the driver for the analog LEDs. The compressor always operates in Class-A mode ensuring minimal distortion and a warm, pristine, and punchy sound.
 
Transconductance Amplifier
The mpressor features a discrete and temperature-compensated transconductance amplifier, which contains a pair of differential transistors that use a modulated current source to alter the amount of amplification. Put simply, this ensures that the circuit avoids any unwanted noise or external influence and can respond very quickly to control voltages, allowing for incredibly fast attack rates and changes in dynamics. This runs parallel to the sidechain path and makes sure that background noise always stays at the same level regardless of amplification level.
In order to compensate for the vulnerability of delicate electronics to temperature variation, the system employs a heating technology, inspired by high-precision measuring instruments, to minimize this variation by arranging 12 discrete transistors inside a massive copper ring that is heated to a precise thermal level. Once the system has reached its desired temperature, it only needs a small amount of current to reliably maintain this level, meaning that much like professional tube-based amplifiers, the mpressor should be given a small warm-up time to reach optimal performance.
 
Magnificent Build Quality
With an extreme eye for detail, elysia has ensured that the mpressor is made to the highest build-quality standards. Proudly engineered and made in Germany, elysia utilizes only custom-designed parts and every unit is handcrafted to order and tested in their headquarters in Nettetal, Germany.