AFB+

NOISE GATE

The AFB+ (Anti‑Feedback Plus) is an acoustic harmonica anti‑feedback and tone control device, handcrafted in the U.S. by John Kinder before he integrated the circuit into HarpKing amps. It suppresses feedback while preserving volume and tone, and adds mic calibration and a 5 MΩ impedance output for optimal amp compatibility. This allows harmonica players to push tube amps into their "sweet spot" without squealing.