<> Lets you hear your instrument's dynamic range and clarity to inspire you to "pick up your guitar and play" <> These high-quality, low-priced headphone amps offer built in compression, volume control and auxiliary stereo input/output <> You can even route the output to a mixer for recording! <> The Bass Ace offers selectable treble boost and mid boost to add to your sound he Rockman® Ace line lets you hear your instrument's dynamic range and clarity to inspire you to 'pick up your guitar and play'. These high-quality, low-priced headphone amps offer built in compression, volume control and auxiliary stereo input/output.