Rolls DB24 Passive Stereo Direct Interface - Transformer DI Box

Rolls DB24: A Fully Passive Stereo Direct Box That Kills Hum and Matches Levels

The Rolls DB24 is a two-channel passive stereo direct interface that connects unbalanced stereo gear to a balanced professional system using transformer isolation. It exists for one of live and studio audio's most persistent headaches: consumer stereo sources hum, buzz, and fight the mixer when patched in directly. The DB24 uses Rolls proprietary audio transformers to isolate and balance the signal, breaking ground loops and matching levels without any power at all. It offers a generous set of inputs, dual balanced outputs, and per-channel ground lift in a rugged steel chassis. For anyone connecting a laptop, media player, or stereo device to a real PA or console, the DB24 is the clean, dependable bridge.

Fully Passive Transformer Design

The DB24 is fully passive, using Rolls proprietary audio transformers instead of active circuitry, so it needs no power, no battery, and no phantom to do its job. Transformer isolation physically separates the source ground from the destination ground, which is the most effective way to break the loops that cause hum and buzz. Because there is no active stage, there is nothing to add noise or distortion and nothing to fail for lack of power. The transformers also convert the unbalanced source to a balanced output that travels cleanly down long cable runs. For a direct box expected to work silently and for years, that passive transformer core is the foundation of the DB24.

Versatile Inputs and Balanced Outputs

The DB24 accepts a stereo source on RCA, 1/8-inch, and dual 1/4-inch inputs, so nearly any consumer or prosumer device connects without an adapter. From that source it delivers dual balanced XLR outputs, feeding the two channels of a mixer or snake as a proper professional signal. With a 50k ohm input impedance it loads the source lightly and preserves its tone, while its 600 ohm outputs drive long balanced runs cleanly. Having three input connector types on one box means the same DI covers a laptop today and a media player tomorrow. For a working patch point, that connector versatility is what makes the DB24 endlessly useful.

Ground Lift, Mode Switching, and Clean Specs

The DB24 provides a ground-lift switch on each channel, individual variable attenuators, and a stereo/dual-mono switch, giving hands-on control over how the signal reaches the console. Per-channel ground lift lets you kill hum on one side independently, while the attenuators tame a hot source before it hits the mixer. The stereo/dual-mono switch lets the box pass a true stereo pair or treat the two channels as separate mono feeds. Across a flat 20 Hz to 20 kHz response, the passive path stays clean and full. For an engineer fighting hum and level problems on a stereo source, that combination of controls is exactly the toolkit the DB24 hands over.

Rugged Steel Build With Gold-Plated Jacks

The DB24 is built into a heavy-duty powder-coated steel chassis with gold-plated jacks for reliable, corrosion-resistant connections. A metal enclosure protects the transformers and survives the handling of stage and studio life where a plastic box would crack. Gold-plated jacks resist the oxidation that makes worn connectors crackle and drop signal over years of use. The compact, solid form factor sits easily on a stage floor or in a patch area without taking over the space. For gear that gets stepped on, packed, and repatched constantly, that durable build is what keeps the DB24 working season after season.

Connecting Consumer Stereo Gear to Pro Systems

The DB24's purpose is joining unbalanced stereo sources to balanced professional systems cleanly and quietly. A live engineer can bring a laptop or media player into the console through the DB24 and lift ground to silence the hum a direct connection would cause, and a studio can patch consumer stereo gear into balanced inputs while the transformers isolate it. The variable attenuators handle sources that are too hot, and the mode switch adapts to stereo or dual-mono needs. Because it is passive, it drops into any rig without a power concern. For the everyday task of getting stereo consumer audio into a pro board without noise, the DB24 is built for exactly that.