keeley compressor plus keeley compressor plus. the keeley compressor plus will help you on your quest for achieving the very best tone. this pedal will smooth out your sound, polish your tone, make your sustain sing and breathe new life into each note you play. the sustain from the keeley compressor plus blossoms and blooms like tube amp compression. the compressor plus has the precision of a studio rack mount jfet compressor, but fits conveniently on your pedalboard, so you can take it with you wherever you go. the plus offers you a blend that gives you the transparency and freedom of the world's greatest levelers and limiters. tens of thousands of players have trusted keeley compressors for articulate, expressive sustain.