The CompIQ STELLA Pro is a meticulously crafted, all-analog compressor pedal for guitar and bass. It can be powered by an external supply or an internal battery and is built around the top-of-the-line 4320 THAT Analog Engine®, providing unmatched control and versatility Key features True analog bypass Blackmer® VCA analog compressor Optional DITOS board for transformer-coupled balanced output (10KΩ impedance) True RMS-level detector Ratio 1:1 – inf:1 (limiter) Threshold -40dBu to +10dBu Make-up Gain -6dB to +20dB X-EQ with selectable frequency pivot 330Hz for bass or 1KHz for guitar Soft/Hard compression knee Manual timing: attack 0.12 to 12 ms/dB of gain reduction, release 1.2 to 120 ms/dB of gain reduction Fast/Slower dynamic auto attack and release timing with hold for peaks over the threshold Normal/Low/Deep side-chain filter Dry/Wet mix Tape Saturation on the dry line with Level compensation and Low/High-frequency cut filters (jumper selectable) 8-LEDs gain reduction meter Hi-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-years warranty (direct to manufacturer, international, transferable