Crank Your Favorite Tube Amp Anywhere—Without the Noise Complaints
For decades, the only way to get the true, glorious harmonic compression and sustain from a tube amplifier was to turn the volume up to window-rattling levels. The Universal Audio OX Amp Top Box completely rewrites that rulebook. It provides a safe, reactive load that behaves exactly like a real speaker cabinet, protecting your amplifier while letting you capture that "sweet-spot" power-tube saturation at any volume, or even completely silently through headphones.
But OX goes far beyond a standard attenuator. Utilizing Universal Audio's legendary DSP modeling, it provides exceptionally realistic emulations of classic speaker cabinets, microphone placement, and premium studio rooms. Whether you want a vintage 4x12 stack driven by ribbon mics or a boutique 1x12 open-back combo in a lush wooden tracking room, OX delivers album-ready guitar tones straight to your recording interface or live mixer.
Product Description
Premium Reactive Load Box and Attenuation:
Unlike passive load boxes that flatten out your amp’s natural frequencies and crush your dynamics, OX utilizes a premium reactive load circuit. It continuously mirrors the complex electrical impedance variations of a real guitar speaker. This ensures your tube amplifier responds naturally, preserving all the touch-sensitive dynamics, high-end bite, and low-end sag you love. The front-panel Speaker Volume knob lets you step down the output volume going to your physical speaker cabinet through 5 distinct attenuation levels without sacrificing a drop of tone or sustain.
Revolutionary Dynamic Speaker Modeling:
At the heart of OX’s recording capabilities is UA's Dynamic Speaker Modeling. This groundbreaking technology goes far beyond static Impulse Responses (IRs). It models real speaker behavior, including cabinet resonances, speaker cone cry, and the musical distortion that occurs when a speaker is pushed hard. Using the Rig control knob on the front panel, you can instantly cycle through 6 fully customizable presets that pair world-class vintage and modern cabinets with perfectly placed studio microphones.
Studio-Grade Onboard UA Effects & Wireless App Control:
OX features an internal DSP engine packed with legendary Universal Audio processing. You can shape your guitar tracks inside the box using a flawless 1176 compression circuit, studio-grade graphic and parametric EQs, rich delays, and UA's stunning three-dimensional room modeling reverb.
Everything is mixed and managed via the intuitive OX mobile/desktop app, which connects seamlessly to the hardware over an internal Wi-Fi network. This allows you to swap cabinets, tweak microphone choices (such as dynamic, condenser, or ribbon models), adjust mic proximity, and fine-tune your effects chain wirelessly from your tablet, computer, or phone.
Key Features
REACTIVE LOAD TECH: Safely handles up to 150 Watts of pure tube amp power while maintaining authentic amp response and feel.
5 ATTENUATION LEVELS: Instantly drop your stage-ready tube amp volume down to bedroom or whisper levels without changing its tonal character.
DYNAMIC SPEAKER MODELING: Recreates authentic speaker breakup, cabinet resonance, and room acoustics without static IR limitations.
FRONT-PANEL RIG SELECT: Quickly browse 6 fully curated, album-ready cabinet/mic combinations directly from the physical hardware knob.
ONBOARD DSP EFFECTS: Polish your tracks with legendary UA effects, including an 1176 compressor, studio EQ, delay, and stereo room emulation.
SELECTABLE IMPEDANCE: Built-in hardware switch handles 4 Ω, 8 Ω, or 16 Ω amplifier outputs to match any head or combo setup perfectly.
WIRELESS APP EDITING: Tweak mic selection, room parameters, and effects chains using the dedicated OX app over a built-in Wi-Fi connection.
PRO DIGITAL & ANALOG I/O: Features balanced stereo line outputs, an optical/coaxial S/PDIF digital out, and a dedicated high-fidelity headphone jack.
Technical Specifications
Feature
Specification
Product Type
Reactive Load Box, Attenuator, and Guitar Recording System
Max Power Handling
150 Watts RMS Maximum Continuous Power Peak
Selectable Impedance
4 Ω, 8 Ω, or 16 Ω (Selectable via Rear Switch)
Attenuation Controls
6-Position Front Panel Knob (From Full Bypass down to Silent)
Rig Presets
6 Customizable Factory/User Presets (Selectable via Front Panel)
Digital Processing
Onboard UA DSP Modeling, Effects, and Room Simulation
