First Listen: A Review of the Universal Audio OX Amp Top Box

Last week I was lucky enough to sit in on a demo of the newest product from Universal Audio, The OX Amp Top Box. Universal Audio has been setting the standards of analog gear in professional recording studios for decades (see the 1176 or LA-2A), but they have spent more and more time recently in the digital realm. Over the past few years, Universal Audio has been breaking ground on their UAD-2 software platform and working hard to set new standards in the digital age. The OX is a perfect integration of the musicality, depth, and warmth that we love from UA's analog gear and the state of the art software emulation that makes you forget there is any digital processing involved. First and foremost, the OX is a premium reactive load box, which will allow a guitarist to play or record their tube amp in the ideal "sweet spot." Often times, amps like Marshall Plexi Half Stacks or Fender Deluxe Reverb can be insanely loud when you hit the "sweet spot" of the amp. This renders them unusable in most live venues, or even being in the same room while recording. The "sweet spot" is the point where the amplifier's tubes begin to break-up, and you get that beautiful tube saturated overdrive. As mentioned before, when an amp gets that loud, it becomes very painful to listen to. Let's get familiar with the set-up, functionality and how the Ox works as a reactive load box. You plug into the front of your tube amp like you normally would, then you run the speaker output of the head into the OX. You then run out of the OX through its speaker output, back into your speaker cabinet. In this set-up, you are dealing with just the brown stripped section of the OX. The "Speaker Volume" dial deals with the output volume of your speaker cabinet. Turned all the way to "5," you are hearing the full output of your amplifier and cabinet as if the OX was not in the chain. By turning the dial back, you are attenuating the output of the speaker, but maintaining the tone you had at full volume. Now you crank your amp up to 11 to get that sweet tube overdrive we mentioned earlier, then back down the volume to fit any size room and you can even turn the speaker off. The amplifier output is also feeding the "Headphone" dial, an independent output from the "Speaker Volume," and can be used all on its own. This makes the OX ideal if you'd like to practice quietly, but maintain the same feel as your full rig. Now we get into the juicy stuff that sets the OX apart from its competitors like the Suhr Reactive Load, or Fryette Power Station. Not only is OX the world's best reactive load box, it also runs an app designed by Universal Audio that does speaker emulations, vintage microphone emulation, room tone models, reverbs, delay, compression, and EQ. The app has a beautifully designed, user-friendly interface, and can be run on iOS tablets or phones.

Inside the app, choose between a variety of speaker cabinets in all shapes and sizes, including everything from vintage Greenbacks to Bull Dogs to small lo-fi speakers, each with a great graphic display. The OX really captures the speaker's unique breakup and cone cry.

Once you've chosen your cabinet, pick from a variety of microphones like a Shure SM57, Royer 121, Sennheiser MD421, or a vintage Neumann U67 to mic up the cabinet. You can choose up to three microphones at one time, each with their own parametric EQ controls, and individual faders to blend them to taste. You can also dial in how much "Room" tone you want, which will make you sound as if you are playing in a professional recording studio with a big live room. This can be adjusted inside the app, as well as the "Room" dial on the front panel of the OX. You can then dial in reverb and delay settings, both effects were designed by Universal Audio, and sound absolutely amazing, with tones of variety to cover any genre. Lastly, you can insert an 1176 compressor into the signal path, and it sounds great, it's the same 1176 plug-in as used on their UAD-2 platform.

On the rear panel of the OX, there are two line outputs, and a single S/PDIF digital output for stereo recording. By using the line outputs on the rear panel, you can send the sound of your tube amp through all the emulations available, directly into your DAW, or FOH at a live venue. Since the reactive load is sending an exact copy of your signal, this eliminates the need to mic your physical guitar cabinet. This would be great when playing a small room where even the natural volume of your amp is too loud before the PA, with OX, you could turn your speaker down to use as a personal monitor, then send the Line Out to FOH. The engineer will then have precise control on how to fit the guitar into the rest of the mix. In a studio setting, you could still mic your cabinet to get the true sound of your rig, but also record the line outputs of OX and experiment with different speaker cabinets and microphones. It could be a great way to add lots of depth to your guitar recordings, and same a lot of time by not having to re-amp, or replay the part with a different set-up. Every combination of speaker cabinet and effects settings you create can be saved and recalled inside the app. You can assign up to six custom presets to the "Rig" dial on the front panel of the OX, allowing you to easily pull up album quality microphone and speaker emulations, without dealing with the app in a live setting. The Universal Audio OX Amp Top Box is priced at $1299, which is quite a bit more than most reactive load boxes, or cabinet simulators like the Radial Engineering Prodigy V8, Rivera Rockcrusher, or Radial Engineering Headload V8.  Yet, with the OX, you are truly getting your money's worth with all the extra features included in the app, and knowing that OX is using the highest quality effects, speaker cabinet, and microphone emulations available, all designed by Universal Audio. The OX is also really vibey looking compared to anything of its kind, it looks as if it belongs in a vintage recording studio. The maple trim and vented steel plate make it pop on top of your amp. The OX is completely silent, and has no internal fan, so it won't bother you while on top of your amp, or be picked up by a microphone. It uses specially designed heat dispersion, and even after being on for a couple hours, was barely hot. I highly recommend getting your hands on one and trying OX out for yourself, as I think they will become a staple in every recording studio and live music venue in a matter of no time.