The Universal Audio Ox Amp Top Box is a reactive load box designed for electric guitarists. It lets you play and record your tube amplifier at ideal volumes and tonal sweet spots, allowing you to do so at levels commensurate with not annoying all of your loved ones or neighbors. Oftentimes, getting the desired tone out of a tube amplifier involves cranking the volume to levels undesirable for living-room studios or small venues; with this device, you can achieve that just-breaking-up tube tone—or even full-on crunch—at lower levels. You can lower the signal hitting the cabinet with the speaker volume knob, while the line-out knob and headphone knob control the levels of their respective destinations. This load box can switch between 4-,8-, or 16-Ohm operations to suit various cabinets.

It should be noted that the Ox is a Universal Audio device, and as such, you can expect access to quality modeling technologies. Should you want to eschew your cabinet altogether, feeding the house PA on stage or your interface at home, a front-panel Rig control has been provided, giving you access to mic and speaker-cabinet emulations that sound like they belong on your favorite album. EQ, compression, delay, and reverb are also on hand, and many configurations can be auditioned when pairing the Ox with a corresponding app over Wi-Fi.

For connections, the Ox offers a 1/4' input (plug your amplifier’s output into here), as well as a 1/4' speaker output, should you wish to route to a corresponding cabinet. Digital recording is made possible with multiple USB and S/PDIF outputs. Furthermore, you can route sound to a PA or recording interface with multiple, balanced TRS 1/4' outputs. A headphone output is available on the front panel for private practicing.