Universal Audio OX Stomp Dynamic Speaker Emulator – a stereo speaker and cabinet emulation pedal from the guitars and amplifiers category, built on the Dynamic Speaker Modeling technology developed for the OX Amp Top Box. Operates at instrument and line level only – it is not a load box or power attenuator. Designed for users of amp modellers, amp-in-a-box pedals, and devices with a preamp line output who need a professional cabinet section with microphones and studio-grade effects in a single pedalboard unit.
Dynamic Speaker Modeling – why this is not an IR loader
Standard IR loaders capture a cabinet's behaviour at a single operating point – a fixed level and mic position – and replay that snapshot statically regardless of input level or dynamics. UA's Dynamic Speaker Modeling computes cone behaviour in real time: speaker breakup under overdrive, cone cry at the limits of excursion, and transducer reactivity responding dynamically to signal level and character. At low playing levels the speaker behaves as a clean, relaxed driver; with a hard attack, compression and saturation appear in the way a worked-hard speaker actually sounds behind a well-placed microphone. OX Stomp adds Dynamic Room Modeling on top of this – the only pedal on the market to model room microphone ambience, simulating the acoustic experience of recording in a proper tracking room rather than just providing a close-mic snapshot.
22 cabinets, 6 microphones, studio effects, and 100+ RIGs
Two mic toggle switches on the front panel let you choose a pair from six vintage microphone emulations – dynamic, ribbon, and condenser – and set their levels independently without opening the app. A third room mic position is controlled by the dedicated Room knob. The Speaker Drive knob adjusts cone saturation independently of input level. The effects section, accessible via the UAFX Control app, includes an authentic 1176 compressor emulation with full Attack, Release, Ratio, Input, and Output controls; plate reverb; a 4-band EQ with hi-cut and lo-cut filters; three delay types (Dual, Crossover, Ping-Pong); chorus; and flanger. All effects are footswitchable. Over 100 RIG presets are available out of the box. MIDI over USB provides 128-preset recall and real-time CC control.
KEY FEATURES
- Dynamic Speaker Modeling: real-time emulation of speaker breakup, cone cry, and Speaker Drive
- 22 guitar cabinets (from 1950s combos to high-gain stacks)
- 6 vintage microphone emulations: dynamic, ribbon, condenser
- Dynamic Room Modeling – the only pedal with full room microphone emulation
- Studio effects: 1176 compression, plate reverb, 4-band EQ (hi/lo-cut), Dual/Crossover/Ping-Pong delay, chorus, flanger
- Over 100 factory RIG presets
- Onboard controls: Mic 1 / Mic 2 toggle switches and level knobs, Room level, Speaker Drive, Output
- Silent switching, buffered bypass, analog dry-through
- MIDI over USB – 128 presets, real-time CC control (UAFX 2.0)
- UAFX Control app: Bluetooth + hardwired USB, RIG editing, footswitch configuration, artist presets
- Stereo I/O: 2x 6.35 mm TS jack IN, 2x 6.35 mm TS jack OUT
- NOTE: not a load box – instrument and line level only
- Power: 9 V DC, isolated, center negative, min. 400 mA (power supply sold separately)
TECHNICAL SPECIFICATIONS
- Type: stereo speaker/cabinet/microphone emulator (instrument and line level)
- Technology: Dynamic Speaker Modeling (UA), Dynamic Room Modeling
- Cabinets: 22
- Close microphones: 6 vintage emulations (dynamic, ribbon, condenser)
- Room microphone: yes (dedicated Room level knob)
- Effects: 1176 compression, plate reverb, 4-band EQ with hi/lo-cut, delay (Dual, Crossover, Ping-Pong), chorus, flanger
- RIG presets: 100+ factory, fully configurable in app
- MIDI: USB-MIDI (128 presets recall, real-time CC)
- Bypass: buffered, silent switching, analog dry-through
- Inputs: 2x 6.35 mm TS jack
- Outputs: 2x 6.35 mm TS jack
- Connectivity: USB-C (MIDI, firmware updates), Bluetooth (UAFX Control app)
- Power: 9 V DC, center negative, isolated, min. 400 mA
- Dimensions: 14.1 × 9.2 × 6.5 cm
- Weight: approx. 590 g