AIR Music Technology Vacuum Classic (ESD); virtual synthesizer plugin; vacuum tube circuit modeling for warm analog sound; two oscillators with waveform morphing across four shapes; mixer with drive/distortion and ring modulation; high- and low-pass filters with saturation option; modulation: two envelopes, arpeggiator; age function with drift and dust controls for authentic vintage character; wide preset library (leads, pads, basses, arpeggios, percussion, FX) designed by Richard Devine and Mark Ovenden; vintage interface inspired by classic tube synths