The range of mid-high audio frequencies (centered around 5 kHz) can be boosted to increase the sense of presence of vocals and solo instruments. As 522’s Presence control is adjusted above minimum, those mid-high frequencies are increasingly boosted during compression, allowing a sound or instrument to cut through or seem more present in the mix. This variable presence function enables the 522 to effectively operate with two different ratios, one for low frequencies (LF) and the other for mid-high frequencies (reduced ratio). The primary effects are: heavy compression and dynamic control can be applied without sounding unnatural; and the reduced compression in the human ear’s most sensitive range makes the material sound brighter. However, since high frequency (HF) make up gain is not required, unwanted noise, pumping, and howl-round during quiet passages are all greatly reduced.
Manual or Auto Modes
When operating in its default mode (Auto switch not engaged) the 522 functions as a peak-sensing compressor, providing tight peak control via instantaneous changes in gain reduction, which produces more obvious compression. This allows the operator to manually adjust the compressor attack and release times so that the compressor operates in peak mode with linear attack curves. When the Auto switch is engaged, the manual attack and release controls are bypassed and the compressor operates in RMS mode, automatically adjusting the attack and release based on the averaged input signal and the threshold/ratio settings. This produces a smooth, more relaxed compression that is perceived as more musical and natural sounding.
Soft or Hard Knee
Another element that affects how natural the output sounds when compressed is how the signal is addressed at and around the knee, or threshold point. By default the 522 is set to Soft knee compression (switch out), which tends to sound more natural as it blurs the distinction between over and under threshold signals, leaving signals below threshold unaffected, while signals just over threshold get compressed at greatly reduced ratios. Only at the point where the signal level rises significantly above the threshold is full-ratio compression applied. This performance is similar to that of many vintage compressors due to non-linearities in gain reduction. When the Hard knee switch is activated, the 522 operates in a more surgical fashion with a more sharply defined transition between under and over threshold, making it ideal for limiting style compression. In this mode a small amount of Soft knee is retained to keep the sound reasonably natural.
Sidechain HPF
COMPRESSOR LIMITER 522’s Sidechain high pass filter (HPF) switch lets you insert a 200 Hz HPF into the compressor side chain, which keeps LF signals from dominating overall signal compression – and effectively eliminates the unwanted artefacts and pumping effects on higher frequencies.
High Performance Balanced Input Stage
Decades of experience, paired with the premium-grade components that make up every input stage we build, ensures the ultimate in signal integrity that is the very foundation of our design process. That warm and organic MIDAS sound has been heard by millions of concert goers – and recorded for posterity on countless live albums. The input stage of the 522 is second to none with its low noise performance, which boasts an enviable Common Mode Rejection Ratio (CMRR) of -70 dB @ 1 kHz.
Transistor Driven Transformer Balanced Output
The output stage of any audio processor is the most critical when it comes to maintaining signal integrity, so the 522 utilises discrete bipolar transistors for both their low distortion and noise characteristics. To finalise the balanced output, a premium quality transformer is employed in order to minimize distortion and maximize clean headroom. 522’s transformer also provides galvanic isolation and generates a more vintage sound, and becomes saturated at lower frequencies to add colour when driven hard.
Precision Metering
The COMPRESSOR LIMITER 522 provides at-a-glance metering with LED stacks that display Gain Reduction and Level independently of each other. The 6 segment Level meter reads from -30 dBu to +20 dBu in 10 dB steps, while the 10 segment Gain Reduction meter reads from -2 dB to -20 dB in 2 dB steps.
True Hardware Bypass & Power Up Mute
For those occasions when compression is not needed, 522’s IN switch can be disengaged to remove all circuitry from the signal path via true hardware relay bypass. Additionally, true bypass mode engages should the chassis become accidentally powered down.
Variable Dynamics & “Air”
