We’ll start with the bottom line: OX will let your tube amp sound its best at every gig, every session, at any level. Your favorite amp tones and dynamics, mics, mic placements, room sounds and speaker cab emulations are now available every time you plug in.

We realize that’s a big boast, but with some of our favorite players and touring concert pros adding the OX to their tube amp rigs—and with our confidence in Universal Audio’s innovative, consistently dependable technology—we don’t think it’s over the top.

In a nutshell: OX is the world’s finest boutique speaker attenuator and guitar amp recording solution. It is a top-of-class reactive load box, that lets you crank your tube amp up to its ideal sweet spot but keep it at a reasonable playing level, whether live or in the studio. OX uses state-of-the-art software and UA’s dynamic speaker modeling to model a variety of classic speaker cabinets, classic dynamic, ribbon and condenser microphones, mic placements, reverbs and delays, room tones, EQ, and compression. Killer tone, every time.


  • Premium analog reactive load box and guitar recording system for tube guitar amps*
  • Album-quality mic and speaker cabinet tones via front-panel RIG control
  • Virtual mics and cabs, expertly-placed (no amp miking required)
  • 5 guitar amp attenuation levels, from dead silent, to whisper-quiet, to full band volume
  • UA Dynamic Speaker Modeling emulates speaker drive, 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 outs for stereo recording
  • OX mobile or desktop app (over Wi-Fi) for editing and saving RIG presets
  • Footswitchable control of OX's studio-quality effects

* OX can be used with solid state amps, but be careful not to exceed the OX's maximum input power handling of 150W RMS.

More from UA:

OX is a premium reactive load box and guitar recording system, giving you perfectly studio-miked amp sounds from your favorite tube amp. OX lets you play and record your amp in its sweet spots — from huge clean tones and edge-of-breakup to fully cranked — at any volume level, and with mic, room, and speaker cabinet emulations at the turn of a knob.

UA’s Dynamic Speaker Modeling, makes this the first system to accurately emulate speaker drive, breakup, and cone cry, making it the world’s finest speaker attenuator and guitar amp recording solution. With the Speaker Breakup knob in the OX app, you can control the harmonics and sonic complexity that occurs only at certain frequencies and volume levels on various speakers — the same sonic phenomenon that occurs with a real speaker cabinet.

UA engineers set out to design a reactive load box that retains the tone, dynamics, and feel of your tube amp — no matter how much it’s attenuated. The goal was for your tube amp to “see” OX as an actual speaker — with continuously variable impedance and response — so you don’t lose a drop of tone or playing dynamics.

OX’s front-panel, six-position RIG control allows you to quickly choose from complete setups — including emulated speaker cabinets, close mics, ambient room mics, and up to four simultaneous studio effects. OX is also the only guitar recording system to offer a complete selection of expertly placed room mics, giving you the authentic experience of pushing air while recording your cranked amp in a world-class tracking room.

OX features a front-panel headphone jack for silent practice with your cranked tube amp, and rear-panel connections for all kinds of recording and live workflows. Stereo S/PDIF digital outputs via RCA and optical TOSLINK, as well as balanced TRS stereo line outputs with front panel level control, give you the necessary connections for studio monitors, DAW, or live mixing console inputs. Plus, you can connect any one, two, or three-button footswitch and toggle OX's studio-quality effects on and off.

The OX software app offers slick, intuitive control over all of OX’s RIG settings via Wi-Fi — letting you tweak, store and recall hundreds of presets from your iPad, Mac, or Windows 10 computer. You can then save your six favorite tones onto OX’s front-panel RIG knob for instant recall in the studio or at a gig.

ConditionBrand New (New)
Brand New items are sold by an authorized dealer or original builder and include all original packaging.learn more
  • OX Amp Top Box Attenuator
  • White / Brown / Wood Grain
  • 2022
Made In
  • United States

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Joined Reverb:2016

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