Yes — this one is worth rewriting. The current information is useful, but I would put more emphasis on the fact that the dbx Di4 combines four DI channels and a stereo line mixer in one compact unit. That's its strongest differentiator.

I'd also use the brand styling dbx Di4 rather than DBX Di4 throughout the page.

dbx Di4 4-Channel Direct Box and Stereo Line Mixer

The dbx Di4 4-Channel Direct Box and Stereo Line Mixer combines four independent direct injection channels with a convenient stereo line mixer in a compact half-rack chassis. Designed for live sound, stage, studio, and keyboard applications, the Di4 makes it easy to connect multiple unbalanced instrument or line-level sources to the balanced microphone inputs of a mixer or professional audio system.

Each of the four channels provides an unbalanced 1/4-inch input, balanced XLR output, 20 dB pad, ground lift, volume control, and pan control. In addition to the individual XLR DI outputs, signals can be combined through the built-in stereo line mixer and sent to a pair of RCA outputs.

A dedicated headphone output provides convenient local monitoring, making the Di4 particularly useful for keyboards, electronic instruments, samplers, sound modules, and multi-instrument stage setups.

Four Independent Direct Box Channels

The dbx Di4 provides four DI channels in a single compact enclosure, reducing the need for multiple individual direct boxes.

Each channel accepts an unbalanced signal through a 1/4-inch TS input and provides a balanced XLR output for connection to a mixing console, stage box, recording system, or other professional audio equipment.

This allows several instruments or audio sources to be connected through one centralized DI unit.

Individual 20 dB Pad and Ground Lift

Every Di4 channel includes its own 20 dB pad switch, allowing the input level to be reduced when connecting higher-output sources.

Each channel also provides an independent ground lift, which can be used to help resolve hum caused by ground loops between connected audio equipment.

Having these controls available independently on all four channels provides greater flexibility when multiple instruments or sources are connected simultaneously.

Built-In Stereo Line Mixer

In addition to operating as a four-channel DI box, the dbx Di4 functions as a stereo line mixer.

Each input channel has independent volume and pan controls, allowing the connected sources to be positioned within the stereo mix. The combined signal is available through the stereo RCA outputs.

A master volume control provides overall adjustment of the stereo line mixer output.

This makes the Di4 particularly useful for keyboard players and electronic musicians who need to combine multiple instruments or sound modules before sending the signal to another audio system.

Headphone Monitoring

The built-in 1/4-inch headphone output provides convenient monitoring of the line mixer.

This allows musicians and technicians to monitor connected sources directly from the Di4 without interfering with the individual balanced XLR outputs being sent to the main mixing console.

Compact Half-Rack Design

The Di4 combines four DI channels and line-mixing capabilities in a compact 1/2-rack-width chassis, making it well suited for stage racks, keyboard rigs, studios, and portable audio systems where equipment space is limited.

Despite its compact size, each channel retains independent controls for the functions commonly needed when interfacing instruments with professional balanced audio systems.

dbx Di4 Key Features

• Four-channel active direct box
• Built-in stereo line mixer
• Four independent 1/4" unbalanced inputs
• Four balanced XLR outputs
• Individual 20 dB pad on each channel
• Individual ground lift on each channel
• Independent channel volume controls
• Independent pan controls
• Stereo RCA line mixer outputs
• Master volume control
• 1/4" headphone monitoring output
• 320 kΩ input impedance
• Compact 1/2 RU chassis
• Designed for live sound, studio, stage, keyboard and instrument applications

Using the dbx Di4 as a Direct Box

When used as a four-channel DI, connect instruments or other unbalanced sources to the 1/4-inch channel inputs. The corresponding balanced XLR outputs can then feed a mixing console, stage box, recording console, or other balanced audio input.

For high-output sources, engage the channel's 20 dB pad as needed. The individual ground-lift switches can be used when necessary to address ground-loop hum.

Using the dbx Di4 as a Stereo Line Mixer

The Di4 can also combine the four connected sources into a stereo mix.

Individual volume and pan controls allow each channel to be adjusted within the stereo output. The master volume controls the overall line-mixer level, while the RCA connectors provide the stereo output.

The headphone connection provides convenient local monitoring of the mix.

Ideal Applications

The dbx Di4 is particularly useful for:

• Keyboards and synthesizers
• Electronic instruments
• Samplers and sound modules
• Live performance rigs
• Stage monitoring systems
• Recording studios
• Rehearsal systems
• Multi-instrument setups
• Portable PA systems
• Professional audio installations

dbx Di4 Specifications

Why Choose the dbx Di4?

For applications requiring several direct boxes, the Di4 consolidates four DI channels into one compact device while adding stereo mixing and headphone monitoring capabilities.

That combination is particularly useful for keyboard players and electronic musicians using several sources on stage. Individual balanced XLR outputs can be sent to the front-of-house console while the built-in mixer provides additional control and monitoring at the performer's position.

Why Buy the dbx Di4 from Audio Supply?

Audio Supply provides professional direct boxes, mixers, signal processors, interfaces, cables, and live sound equipment for stage, studio, commercial AV, and installed audio systems.

If you're putting together a keyboard rig, stage system, or multi-channel audio setup, our team can help with the Di4 and related cables, mixers, rack accessories, and other professional audio equipment.