Vox VESI Smooth Impact Tube Compressor PedalThe Valvenergy 2nd Series SMOOTH IMPACT is a genuine vacuum tube compressor that utilizes the gain variation resulting from fluctuations in Nutube's power supply voltage. It marks the debut of a pedal type vacuum tube compressor, offering a distinct, natural playing feel unlike compressors of other types. Instead of conventional VCA, optical, or FET methods, it harnesses the non linear realm of tubes, featuring harmonics derived uniquely from vacuum