DBX DI4 4-Channel Direct Box

The DBX DI4 is a four-channel active direct box and line mixer housed in a compact half-rack unit, designed to convert unbalanced instrument signals into balanced XLR outputs for mixer and PA use. Four independent DI channels share a chassis measuring just 44.5 mm tall, with each channel offering its own 20 dB pad and ground lift switch. The unit also functions as a stereo line mixer with RCA master outputs, enabling keyboardists and electronic musicians to consolidate multiple sound sources into a single rack unit with independent front-of-house and monitor sends.

Each of the four channels accepts 1/4" TS unbalanced input with 320k ohm input impedance, handling peak levels up to +15 dBu before engaging the pad. Balanced XLR outputs deliver +16 dBu maximum with 600 ohm output impedance and a frequency response of 20 Hz–20 kHz. THD+noise measures just 0.0008% at +4 dBu, while interchannel crosstalk remains below -90 dB across the full audio spectrum. The front panel provides individual volume and pan controls for each channel, feeding a stereo RCA line mixer output on the rear alongside a 1/4" headphone jack with dedicated master volume control.

The DI4's dual functionality addresses stage and studio scenarios where multiple keyboards, samplers or modules require both balanced outputs to a front-of-house console and a separate monitor mix. Independent pan and level adjustment per channel allows precise stereo placement and balance without touching the main XLR outputs. Universal AC power supply accepts 100–240 V at 50–60 Hz, consuming just 775 mW during operation. The unit weighs 1.75 kg and occupies minimal rack space, making it straightforward to integrate into touring rigs or permanent installations.

Features

• Four independent active DI channels in compact half-rack 44.5 mm chassis
• 1/4" TS unbalanced inputs with 320k ohm impedance, +15 dBu peak level
• Balanced XLR outputs deliver +16 dBu maximum with 600 ohm impedance
• Independent 20 dB pad and ground lift switch per channel
• Stereo line mixer with individual volume and pan controls per channel
• RCA master outputs and 1/4" headphone output with dedicated volume control
• Frequency response 20 Hz–20 kHz, THD+noise 0.0008% at +4 dBu
• Universal AC power supply 100–240 V, 50–60 Hz, 775 mW consumption