Universal Audio OX Amp Top Box Reactive Amp Load Box with Modeling

Legendary Tube Amp Tone Anywhere, At Any Volume

The Universal Audio OX Amp Top Box is a premium reactive-load box and guitar recording system that lets you play your tube amp in its sweet spot — whether you’re tracking quietly, recording direct, or performing live. No cabinet miking required, yet you still get the full dynamics, feel and tonality of your amp at its best. 

Studio-Grade Features for Guitarists

• Reactive load box with selectable 4, 8 and 16 Ω impedance for use with any tube amp. 

• Front-panel RIG knob to instantly select from expertly tuned amp, cab & room combinations.

• Dynamic Speaker Modeling using Universal Audio’s advanced algorithms to recreate speaker breakup, cabinet interaction and mic positioning.

• Balanced TRS stereo line-outs and optical/coax digital S/PDIF outputs for studio or live use.

• Headphone output with cranked-amp feel for silent practice.

• Wi-Fi enabled mobile/desktop app lets you edit, save and load user presets and custom rigs. 

Why It’s a Game-Changer

With the OX Amp Top Box you retain the genuine feel and tone of your tube amp—rich harmonic content, dynamic response and sag—while eliminating the need to crank for that tone. You can silently record, play late at night, send direct to front-of-house, or use in small rooms with full band volume and zero compromise. 

Specifications

• Reactive Load Box & Recording System

• Impedance Options: 4Ω, 8Ω, 16Ω

• Total Power Attenuation Range (from full volume to whisper silent) 

• Outputs: Balanced TRS stereo line, S/PDIF (optical/coax), Front headphone jack 

• Control: Front RIG knob with Wi-Fi App Editor

• Powered from standard mains (100–240V)

• Warranty & Support: Provided by Universal Audio