OX Amp Top Box

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.

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.

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.

Speaker Cabinets

1x10 Black Cha
This small, open-back vintage 10-inch speaker has that classic small amp honk. 
1x12 Blue J
This 50s-era cabinet and speaker delivers classic American open-back 12-inch speaker tones. 
1x12 GB25
This ‘50s-era open-back cabinet is paired with a more overdrive-friendly British 25 “green” speaker. 
1x12 Blu 15
Using a low-wattage “blue” 15-watt speaker, 
1x12 Black D-ux
This mid ’60s-era cabinet and speaker delivers classic open-back 12-inch speaker combo tones. 
1x12 Black GB30
This open-back cabinet is paired with a more overdrive friendly British 30 “green” speaker. 
1x12 JBG 125
Similar to the extended range and power handling of the JBF 120 with its aluminum dust cap, this speaker also has a large voice coil, but with a paper dust cap. This rare speaker, favored by the most famous boutique amp builders of the ‘70s and ‘80s, delivers an articulate sound for cleans but with a warmer overall tone.
2x10 V-UX
This late ’60s-era cabinet and speaker delivers classic open-back two 10-inch speaker combo tones. 
2x12 Two Verb
The classic pairing of American made 12-inch vintage speakers in an open-back cabinet has great bottom and punch. 
2x12 JBF 120
This late ’60s-era cabinet, used by the biggest players in Country, Surf, and Psychedelic Rock, relied on the incredible punch and articulation of these speakers. This cabinet really shines with loud and clean tube amps.
2x12 Black 8H
This custom half-closed cabinet features the highly sought after “black” high-wattage speakers favored by early ‘80s metal players. These aluminum-capped speakers cut right through any mix with ease. 
2x12 Ace Top
This mid ’60s-era cabinet with “silver” speakers delivers classic British open-back 12-inch speaker combo tones.
2x12 Boutique D65
This custom ported cabinet features British style 65-watt speakers and is the choice of many modern blues and rock players. The speaker and cabinet combination delivers tight bottom end clarity. 
2x12 Alnico 50
This closed-back cabinet features two modern, American made Alnico 50-watt speakers. Designed for smooth and singing single note tones when using high-gain.
4x10 Bman
Although this classic pairing of four 10-inch speakers in an open-back cabinet was originally meant for bass, it’s just as great for guitar tones. This setup has a scooped midrange and extended presence.
4x12 GB25 Thick
This vintage closed-back cabinet with four 12-inch speakers is the sound of rock guitar. With original “green” 25-watt speakers. This specific vintage cabinet has an extended low midrange and bass response.
4x12 GB25 Punch
This vintage closed-back cabinet with four 12-inch speakers is the sound of rock guitar. With original “green” 25-watt speakers. This specific vintage cabinet has a moderately scooped midrange delivering a tighter sound.
4x12 GB 30
This vintage style basketweave, closed-back cabinet with four 12-inch speakers is great for distorted classic rock tones. These “green” 30-watt speakers have lots of treble definition with a tight bass response. 
4x12 UK VEE 30
This vintage style closed-back cabinet with four 12-inch speakers is one of the industry standards for modern rock and metal guitar. This cabinet and speaker setup has an aggressive upper midrange edge. 
4x12 CA VEE 30
This modern and deep closed-back cabinet with four 12-inch speakers was designed for heavy, distorted, and scooped amp tones. This cabinet and speaker setup has a forward low midrange with high end edge. 
4x12 Super 80
This custom ported cabinet features four 12-inch vintage “lead” 80-watt speakers. These speakers have a soft treble response, but with an aggressive and forward midrange. 
4x12 White 75
This custom ported cabinet features 12-inch “white/cream” 75-watt modern British speakers. These speakers have an extended treble/presence frequency response.

Cabinet Microphones

The six close mics (and one DI box) used on each of the speaker cabinets are listed below. The close mics can be individually accessed for any cabinet within the OX software app. Dynamic Speaker Modeling allows any single close mic, or any two different close mics, to be used on any cabinet. The close mics can be panned for stereo captures. Additionally, because Dynamic Speaker Modeling allows each close mic to be individually positioned on or off axis, an extraordinarily broad sonic pallet is available.

DYN 57
The dynamic “57” has been the industry standard in the US for recording loud guitar
amps since the late ’60s. Our model is based on a vintage unit from the ’70s. With a
natural bass roll off and accentuated upper midrange, this mic always cuts through any
mix with practically no need for console EQ.
DYN 421
The dynamic “421” has been a favorite choice for guitar in Europe since the early ’60s.
Our model is based on a vintage white unit from 1963. The “421” has thicker bottom
end and smoother treble response than the dynamic “57” making it a great choice for
smooth distorted tones.
RIB 160
The ribbon “160” was used by England-based recording engineers to capture loud guitar
amps and drums on some of the greatest rock records of the late ’60s. Our model is
based on a vintage silver unit from the ’60s. It has a smooth midrange and warm treble
response.
RIB 121
The ribbon “121” is a modern classic for electric guitar. With its silky high end and
extended bass frequency range, many engineers pair the “121” with the “57” to even
out the sound. The “121” is also great on its own, but depending on the speaker, you
may want to use LOW CUT on the mic channels.
CON 414
The condenser “414” is the perfect mic for capturing high end clarity and low end
punch. This solid-state condenser mic can instantly deliver a modern-sounding “smile”
EQ curve. Depending on the speaker, you may want to use LOW CUT on the mic
channels. 
CON 67
The condenser “67” can be heard on the biggest pop and rock records of the ’60s, ’70s,
and ‘80s. This tube condenser mic has a wide frequency range without sounding harsh
or bottom heavy. It has a gentle upper midrange that’s great for distorted rhythm guitars.
DIRECT
In direct mode you get the raw sound of your amp, without a guitar speaker, while still
responding as if the amp is driving a proper reactive speaker load.

Room Microphones

The five room mics capture the ambience of a high quality recording studio room for OX’s Dynamic Room Modeling. Matched stereo pairs are available for stereo ambience.
The room mics can be individually accessed for every Rig within the OX software app.

RIBBON STEREO
These ribbon mics are placed in the drum area of the tracking room. In “live” mode
(DAMP off), this pair has a warm treble response with an overall vintage ‘50s and ’60s
session vibe. With DAMP enabled, baffles and carpeting remove midrange and make for a quicker response time.
CONDENSER STEREO
These tube condenser mics are placed in the drum area of the tracking room. In “live”
mode (DAMP off), this pair has high-end clarity and a thick bottom end. With DAMP
enabled, baffles and carpeting help tighten up the bottom end and make for a quicker
response time.
CONDENSER MAN MONO
This tube condenser mic is placed in the left side of the tracking room (when viewed
from control room). In “live” mode (DAMP off), this mic has a punchy midrange and
thick bottom end. With DAMP enabled, baffles and carpeting help tighten up the bottom
end and tame the midrange.
CONDENSER 67 MONO
This tube condenser mic is placed in the right side of the tracking room by the drum
overheads (when viewed from control room). In “live” mode (DAMP off), this mic has
a smooth midrange and aggressive low end. With DAMP enabled, baffles and carpeting
remove subsonic low end.
RIBBON 84 MONO
This ribbon mic has an old school recording studio vibe. In “live” mode (DAMP off),
it has a dark treble response and overall midrange-based sound. With DAMP enabled,
baffles and carpeting remove midrange, add some treble, and make for a quicker
response time.
RIBBON 121 MONO
This modern ribbon mic adds depth and punch without getting in the way of the close
mics’ high end. In “live” mode (DAMP off), it has a smooth treble response and extended
bass response. With DAMP enabled, baffles and carpeting tighten up the bottom end and there is a quicker response time.