
Universal Audio
Universal Audio OX Amp Top Box Reactive Loadbox
★★★★★
Universal Audio OX Amp Top Box lets you capture studio-quality tones from your cranked tube amp at any volume, from silent to stage-ready.
View price on Amazon
Affiliate Disclosure: Studio Supplies may earn a commission from qualifying purchases made through links on this page, at no additional cost to you. This helps support our editorial team.
Notice a mistake? Let Us Know
Overview
Key Features
Premium, no-compromise analog reactive load box and guitar recording system for tube guitar amps
Instant album-quality mic and speaker cabinet tones via front-panel RIG control
Get record-ready sounds quickly with expertly-placed virtual mics and cabs - no amp miking required
Five finely-tuned guitar amp attenuation levels, from completely silent to whisper quiet to full band volume
UA Dynamic Speaker Modeling emulates speaker drive, breakup and cone cry
Specifications
Type
Reactive Load Box / Attenuator / Guitar Recording System
Compatibility
Tube Guitar Amplifiers
Attenuation Levels
5 (Silent to Full Band Volume)
Speaker Modeling
UA Dynamic Speaker Modeling
Tone Control
Front-Panel RIG Knob
Virtual Microphones
Multiple Expertly-Placed Models
Cabinet Emulations
Multiple Speaker Cabinet Models
Load Type
Analog Reactive
Pros & Cons
👍 Pros
- Reactive load design accurately preserves the feel and response of your tube amp's output stage
- Five attenuation levels allow full-power amp tone from silent recording to stage volume
- Dynamic Speaker Modeling captures realistic speaker breakup, drive, and cone cry
- Front-panel RIG knob provides instant access to a wide selection of cabinet and mic emulations
- Eliminates the need for microphones, mic preamps, and acoustically treated recording spaces
👎 Cons
- Premium price point places it well above most competing load boxes and attenuators
- Designed exclusively for tube amps and not compatible with solid-state amplifiers
- Unit generates significant heat during use due to absorbing the amp's full power output
- Larger and heavier than simpler load box alternatives, requiring dedicated space on or near your amp
- Cabinet and mic modeling options are accessed via the front panel rather than deep software editing
Frequently Asked Questions
Does the OX work as both a load box and an attenuator?
Yes, the OX functions as a premium reactive load box for silent recording and as an attenuator with five levels ranging from completely silent to full band volume.
Do I still need to mic my amp cabinet when using the OX?
No, the OX provides expertly modeled virtual microphones and speaker cabinets, so you get record-ready tones directly from the unit without any physical miking.
What is Dynamic Speaker Modeling?
It's Universal Audio's proprietary technology built into the OX that emulates the way real speakers respond to your amp, including speaker drive, breakup, and cone cry, reacting dynamically to your playing.
How do I dial in different cabinet and mic tones?
The front-panel RIG control lets you instantly scroll through different combinations of speaker cabinet and microphone emulations to find your desired tone.
What types of amps is the OX compatible with?
The OX is designed for use with tube guitar amplifiers. It is a reactive load box built specifically to work with the output characteristics of vacuum tube power sections.