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Universal Audio OX Amp Top Box

Premium Reactive Load Box

Get the most out of your amp at any volume!
Written by

Elliot Stent

The Universal Audio OX Amp Top Box is a cutting-edge unit, allowing you to get the sweetest tones from your tube amplifiers but at ear-friendly volumes. Essentially an amp load box and attenuator, this amazing piece of gear goes one step further - in typical Universal Audio fashion! 

With many sophisticated features such as dynamic speaker modelling and cabinet emulation, the OX also has a dedicated app to let you really fine-tune your tones. Old-school circuitry meets modern flexibility when it comes to the OX, with UA's boutique analogue quality ensuring that none of your base tone is hindered by digital processing, but rather embellished by the convincing modelling technology.

Universal Audio OX - Reactive Load Attenuator & Speaker Simulator Demo

Get The Most Out Of Your Amp - At Any Volume!

Nothing beats the sound of a real, genuine tube amplifier, but they only sound their absolute best when they're cranked. This is usually fine in most live situations, but if you're playing at home and want all of the tonal goodness from your super-loud Plexi or big Fender combo at a lower volume, it's not achievable. But that's where the OX Top Box comes in...

By plugging your amplifier into the OX, the unit ensures that it is safely loaded, to prevent any damage from occurring without the cabinet. A speaker cabinet can of course be used in conjunction with the OX, and with selectable 4, 8, and 16-Ohm operation, most amplifiers will be compatible. 

The main function of the OX though is its attenuation and modelling capabilities. By attenuating your amplifier, this means that you can turn up the master volume so that all of the rich, harmonic content is brought out for the ultimate tone. Then, you can use the OX's own volume control to monitor the overall output, giving you your favourite amp sound at any volume! 

This not only makes the OX Top Box an incredible tool for home use, but also for studio recording. And with balanced TRS line outs and S/PDIF digital outputs, you can record directly into an interface or mixing desk, and even send the signal directly to front-of-house in stereo for a fuller sound when playing live. It's that flexible! 

Speaker & Cabinet Emulation

UA are renowned for their incredible plug-ins for DAWs, and they've integrated their convincing modelling technology into the OX. Fully accessible via the free OX app, you can choose from multiple speaker and cabinet models, with the former capable of emulating speaker breakup and cone cry for the most genuine tones conceivable.

The cabinet models are also very detailed and accurately matched to their real-life counterparts, letting you find the best pairing for your amplifier. This is another great feature that makes the OX perfect for studio use, as you can easily experiment with your setup to find the optimal tone on-the-fly.

And it doesn't end there, as the OX also boasts mic emulations, with the app letting you even adjust its placement on the simulated cabinets/speakers. And top-quality EQ, compression, delay, and reverb effects are also built into the OX, giving you some essential effects to play around with!


  • Get the ultimate tone out of your tube amp — anywhere, and at any volume
  • Pair your amp to the world's best reactive load, with boutique UA analog quality — built for years of home and studio use
  • Instantly audition dozens of album-quality mic and guitar cabinet setups with front panel "Rig" control
  • Get authentic "edge of destruction" tones complete with speaker breakup and cone cry, thanks to UA Dynamic Speaker Modeling
  • Premium, no-compromise analog reactive load box for tube guitar amps
  • Five finely-tuned guitar amp attenuation levels —  from off, to whisper quiet, to full band volume
  • Front-panel “Rig” control for instant, album-quality mic and speaker cabinet emulations
  • UA Dynamic Speaker Modeling emulates speaker breakup and cone cry 
  • World-class Universal Audio EQ, compression, delay, and reverb effects built-in
  • Selectable 4, 8, and 16-Ohm operation 
  • Front-panel Headphone out for silent practice with cranked tones
  • Balanced TRS line outs, and S/PDIF digital outputs for stereo recording
  • Pair with OX mobile or desktop app over Wi-Fi for editing and saving presets
  • Speaker cables not included
Inc. VAT

10+ In Stock

Order now for delivery to you on Monday, 20 September 2021  

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