iFi Audio Go Bar Ultra Portable Music Headphone DAC USB C Balanced 3.5mm 4.4mmiFi Audio GO bar DAC Headphone Amp Premium USB DAC. Worlds most powerful headphone amp of its size. Power to your headphones Small in size but mighty in action, the iFi Audio GO bar delivers class leading power. Compatible with a vast range of headphones, including less efficient designs, the powerful amp controls your headphones superbly offering a crisp, punchy bass with bags of depth. With very inefficient headphones, the Turbo function ramps up