The TC-Helicon Critical Mass is a compact vocal stompbox built to do one thing brilliantly: make a single voice sound like a whole room singing along. It’s now discontinued, so finding one in this condition is getting harder.

What it does

• 4 Gang Vocal styles: Unison, Octave Up, Octave Down, Up & Down – the “everybody sing!” sound of punk, rock, folk and stadium anthems
• 4 Melodic Choir styles: lush choir-like voices that follow your pitch automatically – no key or scale to set
• 3 studio-grade reverbs to add space and depth
• Adaptive Tone: automatic EQ, compression, de-essing and gating for a clean, consistent vocal sound at the push of a button
• Dead-simple controls: Style, Mix and Reverb knobs + on/off footswitch

Built for the stage

• Balanced XLR mic input and XLR output: plugs straight between your mic and the PA
• High-quality, low-noise mic preamp with phantom power (works with condenser mics)
• Rugged die-cast metal chassis
• Runs on 4 AA batteries or an optional power supply – play anywhere, even unplugged busking

Great for

• Singer-songwriters and solo acts who want a “full band” vocal feel
• Punk, rock, folk and indie bands that need big gang-vocal choruses
• Worship and church music, for a choir effect on hymns and refrains
• Busking and acoustic sets (battery powered)
• Home recording and demos: instant thick backing vocals and atmospheric layers
• Creative sound design: octave-down voices for dark, cinematic textures

Condition: Excellent. Fully working, tested before shipping.
Included: pedal, original box. No manual or power supply from factory.

Carefully packed and shipped quickly. Feel free to ask any questions!