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Get Legendary Studio Tones from your Tube Amp — Anywhere, at Any Volume.

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.

Featuring Universal Audio’s breakthrough Dynamic Speaker Modeling, OX is 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.

Play and record your tube amp in its tonal sweet spot — anywhere, at any volume, with full dynamics

Get stunning mic and guitar cabinet combinations at the turn of a RIG knob — no miking required

Audition, tweak, and save more than 100 jaw-dropping custom Rigs from compatible iPad, or Mac/Windows computers.

Get authentic “edge of destruction” sounds, complete with UA Dynamic Room Modeling, speaker breakup, and cone cry

The World’s Best Reactive Load Box

The World’s Best Reactive Load Box

With decades of analog hardware engineering expertise, Universal Audio’s dream team of 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.

A Complete Guitar Recording System

A Complete Guitar Recording System

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.

Dynamic Speaker Modeling

Dynamic Speaker Modeling

UA’s groundbreaking Dynamic Speaker Modeling faithfully emulates speaker breakup, drive, and cone cry — an essential ingredient to authentic tube amp tones. Using 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 — far beyond a static Impulse Response system — giving you the same sonic phenomenon that occurs with a real speaker cabinet.

All The Right Connections

All The Right Connections

Not only does OX Amp Top Box feature a front-panel headphone jack for silent practice with your cranked tube amp, it also sports a bevy of 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.

A Beautiful Software App

A Beautiful Software App

Most guitar products do digital awkwardly. They’re ugly and hard to understand. The OX software app, on the other hand, 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.

Watch The Reviews


      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

      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

      Pair with the OX mobile or desktop app over Wi-Fi for editing and saving RIG presets

      Footswitchable control of OX's studio-quality effects

      OX App Requirements

      OX Amp Top Box

      2.4 GHz Wi-Fi network with internet connection to register (once only)

      (iPad) iOS 12 or iPadOS 13

      (Mac) macOS Mojave or Catalina

      (Win) Windows 10 64-Bit Edition

      Customer Reviews

      OX Amp Top Box

      Overall Rating


      a. kamal

      September 19, 2023

      Love it Love it

      Like many user I am a professional guitar player with a nicely equipped studio where I work….got some nice hardware Tube-Tech,GML,Neve,UAD 610s,6176s etc….as well as a nice small Mike selection (M149,U67,KM84,M586 etc…)but my guitars played through my 64 Bassman head/Marshall JMP,96Diezel Blueface,Boogie,Fender Drev,Princeton,Prev ALL go through the OX!!!!!Beautiful and musical. Cannot rate it high enough. OK, I am completely in the UAD World with Apollo/Ultimate etc….but I wouldn’t use it if I didn’t like it. Also use the Dream 65 instead of my original Vintage Deluxe Reverb more and more.Well done!!!

      S. Ceccarelli

      September 18, 2023

      great sounds but few cabinets.

      beautiful sounds, it's time to add more cabinets.

      J. Zethsen

      September 11, 2023

      More cabinets!

      Very cool equipment! But I want to see updates more often and more cabinets!

      C. Katches

      September 5, 2023


      Another year gone by and no update. Bluetooth works 25% of time. I guess they just gave up on such an expensive investment on customers' part.

      J. PERNIA

      September 4, 2023

      Wifi problems....

      The conectivity options are insufficient. Only wifi... and dont work fine

      S. Williams

      September 4, 2023

      Just what I needed to calm down my neighbors...

      ...but most of all - the right tool to get "that" sound... amazing box... again... well done UAD

      G. Ormson

      September 2, 2023


      DOES MORE than attenuation - great addition to setting up my first recording room. Enjoying all the options for speaker/ amp /effects /simulations.
      Also find the software user friendly so far.
      Find the build quality supports the price tag which is expensive - but waited for my local music store sale and saved.

      T. Szotak

      August 16, 2023

      Should’ve purchased this sooner.

      About a year ago I purchased a Capitor X, it worked ok however the sound always seemed muddy attenuated. I finally stopped using it and sold it.
      Purchased the Ox and I’ll never look back, the app can probably use an update but overall it works beautifully, well worth the extra coin imo.

      J. Sallo

      July 16, 2023

      OX Amp Top Box

      Like this a lot. It's great for low volume practise in an apartment.

      T. Metzler

      July 11, 2023

      Great machine

      Thanks for making this fine sounding and versatile Box.
      It's not only very good to use it with an amp, it is also nice for reamping guitars.
      Nice one

      G. Boudrias

      June 19, 2023

      Awesome Product

      The amp Box is amazing so far. Works great with my Apollo X Twin and also comes with a SPDIF connection that allows me to free those precious 2 XLR inputs.

      The Ox Box works great with my Mesa Boogie and allows me to record guitars so much faster with the same results as if I was using my cab and microphone.

      Great product

      T. Mushen

      June 17, 2023

      Simply Amazing!

      One of the first guitar emulations that really lives up. Feels natural and sounds really good.

      S. Burilina

      May 16, 2023

      OX Amp Top Box

      The best box.Thank you!!!

      S. Burilina

      May 16, 2023

      OX Amp Top Box

      The best box.Thank you!!!

      H. Brett

      April 19, 2023

      Perfection !!

      I’m definitely blown away on how usable this jewel is. Man it’s Smokin when tracking and playing live gigs. I built a 20K guitar rig with Bob Bradshaw back in the day and that was all high end studio gear. Being use to hearing the quality there’s no going back. Now I have a really sweet pedal board instead of the rack effects. I love it! Adding the OX BOX adds to my arsenal with flying colors.

      Thanks for building this quality tool & for going above & beyond.

      功. 佐藤

      April 11, 2023


      UAD pluginでFender 55' DeluxeをLineにして、ラックプリアンプ(bognerやfryetteやsynergy)やペダルプリアンプ(KochやOrigin Effects)を投入した時と同じ様に、OXは歪みに食いついてきます
      スモールアンプ(Mesa mark V:25やSuhr Pt-15)を所持しているとしたら、ノイズフリーで
      かつ 大きな音量、最高の音色とルームリバーブを得る事が出来ます

      G. Doran

      April 1, 2023


      This is probably the most useful tool for guitar recording. I have never felt this strongly

      J. Bradley

      April 1, 2023

      Amazing Piece of Kit

      Over the moon with the OX, it sounds absolutely fantastic and so versatile!

      C. Hevey

      March 21, 2023

      Excellent produit

      Excellent produit de qualité… besoin d’autres update pour incorporer entre autres des cabinets de basse et plus d’options pour les placements de micros.

      G. Teekens

      March 16, 2023

      Great Product!

      Lifesaver & Timesaver. Sounds great and works like a charm. The presets are great too!