NUX Optima Air is a dual-switch acoustic guitar simulator with a preamp for acoustic and electric guitar players. It simulates the acoustic guitar profiles with the best-optimized sound depending on your guitar and pickup type.IR loader combined with a preamp which is equipped with 3-band EQ and Gain controls. And there is an additional one-knob-control Reverb effect. If you want to connect any effect pedal you can use the SEND/RETURN effect loop and add the Optima Air into the signal chain. NUX Optima Air has a unique profile capture function, you can create your own acoustic guitar profile (IR file) by capturing your favorite acoustic guitar's sound. There is an XLR DI output for direct line/mixer connection, headphones output for silent play and auxiliary input to connect a music player to play along.