Universal Audio OX Amp Top Box reactive load box, attenuator, speaker cabinet simulator, and guitar amp recording system.

I bought this unit and have never used it. It has not even been plugged in by me. Because I have not personally tested it before listing, it is sold as photographed and described. Functionality can be confirmed before shipping if required.

The OX Amp Top Box is designed for tube guitar amplifiers, allowing you to connect your amp to a reactive load, attenuate the speaker output, and record or monitor through Universal Audio’s speaker, cabinet, microphone, room, EQ, compression, delay, and reverb modelling. Universal Audio describes the OX as a premium reactive load box and guitar recording system for getting studio-miked tube amp sounds at any volume.

The unit includes the original OX Amp Top Box packaging, foam insert, power supply, mains cable, and Quick Start Guide as shown in the photos. The rear label shows OX Amp Top Box, serial number 21422015016533, and Made in Malaysia.

The unit presents well overall. There are some light surface marks, dust, and normal storage/handling marks visible on the exterior. Please note: I have not opened, serviced, modified, tested, powered, or connected this unit myself. Please review all photos carefully.

Condition

• Excellent used condition
• Bought by me and never used
• Never plugged in by me
• Not freshly tested before listing
• Functionality can be confirmed before shipping if required
• Some light dust / storage marks visible
• Some light handling marks visible under direct light
• No obvious broken parts visible

Specifications

• Brand: Universal Audio
• Model: OX Amp Top Box
• Product Type: Reactive load box / attenuator / speaker cabinet simulator / guitar amp recording system
• Finish: Silver / brown / black with natural wood trim
• Year / Model Range: 2019–2026
• Made In: Malaysia
• Serial Number: 21422015016533
• Power Handling: 150W RMS max
• Use Case: Tube amp attenuation, silent recording, cabinet simulation, direct recording, headphone practice
• Front Panel Controls: Rig, Room, Speaker Volume, Line Out, Headphone
• Front Panel Indicator: Amber jewel-style indicator
• Front Panel Headphone Output: 1/4" headphone jack
• Rear Speaker Connections: From Amplifier, To Speaker
• Impedance Selector: 4Ω / 8Ω / 16Ω
• Line / Monitor Outputs: Left / mono and right outputs
• Digital Output: S/PDIF Out
• USB: USB connection
• Footswitch: Footswitch input/output connection
• Power Input: External DC power supply connection
• Power Requirement: +12V DC, 1.5A, as marked on rear panel
• Connectivity / Control: Designed for use with Universal Audio OX software / app control
• Cabinet / Mic / Room Modelling: Universal Audio Dynamic Speaker Modeling and studio-style cabinet / mic / room processing
• Effects: EQ, compression, delay, and reverb available through the OX system
• Construction: Amp-top desktop / amp-top enclosure with wood trim and vented metal chassis

Included

• Universal Audio OX Amp Top Box
• Original OX Amp Top Box packaging
• Original foam insert
• Power supply
• Mains cable
• Quick Start Guide

Important Safety / Use Notes

• This unit is intended for use with tube guitar amplifiers
• Always use a proper speaker cable between amplifier, OX, and speaker cabinet
• Do not use an instrument cable as a speaker cable
• Correct impedance matching is important
• Rear panel is marked 150W RMS max
• Do not cover top or bottom ventilation
• Chassis surface may become hot during use
• Buyer should read the official manual before connecting to an amplifier

Shipping

The unit will be carefully packed in its original foam insert and original box, then placed inside an outer shipping box with additional protective packing material.

Shipping will be via tracked courier service depending on destination, price, parcel size, and insurance availability. Tracking will be provided after dispatch.

International buyers are responsible for all import duties, VAT, customs fees, tariffs, brokerage / handling fees, and any other local taxes or charges required by the destination country. These costs are not included in the item price or shipping price.

Shipping outside Europe may be possible by prior agreement. Please contact me before purchasing for an exact insured courier quote.