The Alesis iO4 is a compact audio-recording interface for home, project and portable studio recording setups.


This four-channel USB device for Mac and PC-based systems enables users to record and monitor four channels in 16-bit mode or two channels in 24-bit mode.


  • WORKS: Tested under Ubuntu 9.04 on an eeePC using ALSA, Jack and Ardour. Also on Linux Mint KDE 12 with KXStudio. From
  • Note: Audio seems to run only at 44.1kHz, not 48kHz. The io4 is essentially identical to the io2 express (above) but with two additional channels for 4-channel operation in 16-bit mode, and unlike the io2, the io4 is not bus powered. From


  • Analog
  • Inputs - 4 switchable-level XLR, 4 switchable-level TS
  • Outputs - 2 line-level TS (Main), 1 line-level TRS (Headphone)
  • Inserts - 4
  • Phantom power - Yes


  • Out 1
  • In 1