The Sinkhole is perhaps Catalinbread most ethereal reverb unit to date. They’ve combined a harmonically-rich “hole” reverb with an impossibly deep four-voice chorus that’s been outfitted with a feedback control and a gentle high-cut filter. Within this arrangement, the feedback control allows the Sinkhole to reach deep within the reverb to extract some truly otherworldly tunable modulation, featuring everything from comb filtering to pseudo-phaser to haunting auto-filtering. That aspect never gets out of control; it’s all wrapped up within the confines of the reverb. They’ve stretched the reverb trails out to their absolute limit, with the maximum decay time almost freezing your signal in space. Extreme settings evoke warm synthesizer pads, reminiscent of vintage analog-digital hybrids, holding your modulated note indefinitely. Combine all that with a full wet-dry blend and a warm preamp circuit, and you’re beginning to feel the gravity of the Sinkhole.