ART PDB4 4-Channel Passive Rack Mount DI Box

The ART PDB4 is a four-channel passive DI box in a single 1U rack space, made for keyboard players, DJs, live sound engineers and venues that need to connect several unbalanced sources to the balanced XLR inputs of a mixer or stage box. Instead of four loose DI boxes on the floor, you get four isolated channels in one tidy, rack-mounted unit.

Four isolated channels, one rack space

Each of the PDB4’s channels is a complete passive direct box with its own transformer. Inputs and outputs are isolated from each other, which improves separation between channels, and the transformer on each output breaks the ground connection between your source and the mixer. That makes it easier to avoid the hum and buzz that often appear when you connect keyboards, laptops and DJ gear to a PA.

Pads for every source: 0, -20 and -40 dB

Every channel has a three-position input attenuation switch, so the PDB4 can handle a wide range of signal levels:

• 0 dB: for low-output sources such as passive bass or other instrument pickups.
• -20 dB: for line-level sources such as keyboards, synths, drum machines, DJ mixers and audio interfaces.
• -40 dB: for very hot signals, including speaker-level outputs from an amplifier.

If the mixer channel distorts even with its gain turned down, switch to the next pad.

Link jack: amp and mixer at the same time

Each channel has a 1/4-inch parallel link jack wired to its input. Plug your instrument into the input, run a cable from the link jack to your amp, and the XLR output goes to the front-of-house mixer. The player keeps their own amp sound on stage while the engineer gets a clean, balanced feed.

Ground lift for hum problems

A switchable ground lift on each channel disconnects the ground between the input and the XLR output. If you hear hum after connecting a source, flip the lift switch on that channel first. Combined with the transformer isolation, it solves most ground-loop noise at the stage end.

Passive and road-ready

The PDB4 needs no mains power, batteries or phantom power, so there is nothing to fail at the start of a gig. Its all-steel 1U chassis fits a standard 19-inch rack and suits touring racks, keyboard rigs and permanent installations. Find rails, cases and hardware in our rack accessories and cases.

Who is it for?

• Good fit: keyboard players with several stereo instruments, DJs sending outputs to a PA, and live engineers who want a permanent DI rack at the stage.
• Good fit: venues, churches and schools that need dependable, power-free DIs that are always in the same place.
• Good fit: taking a speaker-level feed from an amplifier safely, using the -40 dB pad.
• Not the best fit: passive guitar pickups where you want the brightest possible tone. The 50k ohm input is fine for line sources and active instruments, but a high-impedance active DI usually keeps more top end from passive single-coil pickups.

Passive vs active DI boxes

Passive DIs like the PDB4 use a transformer and no electronics. They handle very hot signals well, need no power and rarely fail. Active DIs need phantom power or batteries but have a much higher input impedance, which suits passive guitar and bass pickups and piezo pickups. For rigs built mostly on keyboards, synths, DJ gear and other line-level sources, a passive multi-channel DI is the simple, reliable choice. Compare single and multi-channel options in our DI boxes range, or see our signal splitters and isolation for other ways to solve ground loops.

Key Features

• Four fully isolated passive DI channels
• Transformer-isolated outputs to reduce ground loops
• Switchable input attenuation: 0, -20 or -40 dB
• 50k ohm 1/4-inch instrument/line input
• 50k ohm 1/4-inch parallel link jack
• 600 ohm balanced XLR output
• Switchable ground lift
• 1U, 19-inch all-steel rack chassis

Why buy from 10dB

Orders leave the 10dB warehouse the same day as your purchase and travel by Australia Post, usually arriving within 3–5 days. Browse more stage gear in our live sound and installation section.

FAQ

Does the ART PDB4 need phantom power?

No. It is fully passive and needs no phantom power, batteries or mains power.

Can I use the ART PDB4 for a stereo keyboard?

Yes. Use two of the four channels, one for the left output and one for the right. Most players set the pad to -20 dB for keyboards.

Can it take a speaker-level signal from an amp?

Yes. Set that channel to -40 dB. This lets you take a feed from an amplifier’s speaker output to the mixer.

Is it good for acoustic guitar with a piezo pickup?

A piezo pickup usually needs a very high input impedance. Unless your guitar has an onboard preamp, an active DI is usually the better choice.

What does the link jack do?

It is a parallel output of the input signal, so you can send the same source to an on-stage amplifier while the XLR feeds the mixer.

How do I fix hum through the PDB4?

Switch on the ground lift for the noisy channel. If hum remains, check cables and make sure the source and the PA share the same power circuit.