BECOS FX CompIQ STELLA Pro Compressor for Guitar and Bass (Gear Hero Exclusive)

The CompIQ Stella Pro MK2 stands out as a remarkably powerful compressor/limiter pedal, offering a wide array of parameters for unprecedented control over playing dynamics. Encased in a compact and sturdy black powder-coated aluminum enclosure, it seamlessly integrates into any pedalboard, no matter the size. The Stella proves versatile for studio applications like bus compression and tracking and delivers outstanding results in live performances. It can be utilized with any instrument, such as guitar, bass, keyboards, synths, electro-acoustic guitars, etc., and even with vocals, provided that an appropriate pre-amp is utilized.

The CompIQ STELLA Pro MK2 is a feature-complete and powerful all-analog compressor/limiter pedals for use with guitar, bass, or any other instrument or audio source. It is also one of the very few that can be powered by an internal 9V battery or an external supply in the range of 9-18VDC. It is built around the high-performance 4320 THAT Analog Engine® which incorporates a true RMS-level detector that accurately measures the input signal and processes it through an ultra-transparent-sounding Blackmer® VCA. Unlike peak detection, commonly used in other compressors, the RMS (root mean square) sensor calculates an average peak level of the signal, aligning more closely with how human hearing perceives differences in loudness.

The pedal offers two selectable compression modes. In Feed Forward mode, emphasis is on speed and accuracy, utilizing a pre-VCA copy of the input signal. This mode can provide subtle compression up to brick-wall limiting based on control settings. The “old-school” Feed-Back compression delivers a smooth response suitable to transparently even out playing dynamics. This mode uses a post-VCA copy of the audio signal for its dynamic processing. While Feed-Back mode excels at low-to-medium compression ratios, it may be less suitable for using compression as an effect or hard peak-limiting. Nevertheless, by adjusting the threshold, employing a hard knee, selecting a higher ratio, setting a fast timing, and even boosting the control signal in the side chain filter, the Stella can function as a genuine Feed-Back limiter. In any settings, both modes sound clean and natural, without pumping, breathing, distortion or other artifacts.

The Stella MK2 features upgraded side-chain capabilities, including a variable Lo-cut/boost filter specifically designed for bass instruments (±12dB @ 90Hz, 12dB/octave). When high-amplitude low frequencies trigger the threshold early, the compressor may engage prematurely, potentially over-compressing high-frequency elements, particularly in specific applications. By cutting lows in the side-chain, compression in the lows at the output is reduced, restoring overall signal energy. Conversely, boosting lows in the side-chain increases compressor sensitivity, aiding with very low-level signals. Moreover, a matching variable Hi-cut/boost filter in the side-chain further refines this balance (±7dB @ 3kHz, 12dB/octave). The cutting side of the filter avoids overly compressing highs, preserving a natural brightness in the output. Conversely, boosting highs in the side-chain enhances compressor sensitivity to high frequencies, which helps with very bright sounding instruments. When both filters are set to cutting, the compressor becomes more sensitive to mid-frequencies within 1-2 kHz, resulting in increased compression in this range at the output. These enhancements effectively manage compression across lows, mids, and highs, delivering impactful dynamics without unwanted pumping and maintaining desired balance in the audio spectrum.

The Compression Knee feature provides two options, each with its particular sonic signature. Hard Knee compression is quick and snappy, suitable for peak limiting or enhancing the compression feel. Soft Knee compression is gradual and gentle, creating a transparent effect even at high ratios.

The X-EQ tilting equalization circuit, rooted in the Hi-Fi era of the 1970s, offers two pivot frequency options: High (at 1kHz) suitable for guitars, and Low (at 330Hz) which works better for bass. This post-compression gentle correction can compensate for differences between instruments or be employed to enhance the lows or highs of the instrument. Both settings can be used in either application, each bringing a different but useful and likable EQ result.

Additionally, the STELLA Pro MK2 features two internal DIP switches for voicing selection. These settings introduce nuanced shifts in the internal dynamic frequency processing, bringing subtle coloring to the sound. The Spark setting adds polished brilliance to the highs, Tight dips the low-mids slightly, providing more depth, and Punch brings a tube-like compression feel with velvety lows and warm highs (which complements even more the DITOS transformer voicing). We will leave the Punch setting activated by default so you can have some fun right away. However, if you want to maintain the most transparent sound response at the output, which always preserves the instrument’s natural character, you may turn the voicing off.

The Dynamic Auto Timing circuit offers user-friendly operation with two selectable options: Fast and Slower. These settings adapt to different playing styles. For added versatility, manual control over Attack and Release timings is available, unlocking a range of other compression possibilities. For instance, setting the compressor for slow attack and fast release allows initial transients to pass through at a higher audio level (set by the Make-up Gain), creating a tight and percussive sound suitable for guitar “chicken picking” or bass “slapping.”

The Stella also features a Dry/Wet Mix, which allows for blending a desired amount of clean signal with the processed signal, resulting in a more natural compression effect. Such a mixing technique (a.k.a. New York style) is usually employed when hard compression is set out as an effect or when limiting must be made more subtle.

An 8-LED gain reduction meter allows for accurate monitoring of the compression applied to the input signal. This feature provides useful visual feedback on the degree of sound processing.

• Full analog circuit with true by-pass
• True RMS-level detector for accurate input signal measurement
• High-performance Blackmer® VCA compression engine
• Optional DITOS board for transformer-coupled balanced output (10KΩ impedance)
• Feed Forward/Feed-back compression modes
• Ratio 1:1 to infinite:1 (limiter)
• Threshold -45dBu to +10dBu
• Make-up Gain -6dB to +20dB
• Soft/Hard compression knee
• Manual timing: attack 0.12-12 ms/dB of gain reduction, release 1.2-120 ms/dB of gain reduction
• Fast/Slower dynamic auto attack and release timing with hold for peaks over the threshold
• X-EQ with selectable frequency pivot 330Hz for bass instrument or 1KHz for guitar or other applications
• Voicing: Flat, Spark, Tight, Punch (internal DIP-switch selectable)
• Lows/Highs variable side-chain filter
• Dry/Wet mix
• 8-LEDs gain reduction meter
• High-end quality FET audio ICs, low tolerance parts, Panasonic & Kemet audio capacitors
• Genuine Hammond black-powdered aluminum enclosure
• Runs on standard 9V internal battery or 9-18 V DC external power supply (not included), center negative, 12mm long barrel plug
• 3-year warranty (direct to manufacturer, international, transferable)
• Hand-assembled in Vienna, Austria

For more information about the CompIQ series of compressors, please see Becos FX's CompIQ 101