Radial ProDI Passive DI
Radial·Model ProDI·radial-prodi
Photos
Manufacturer product photography — the drawn faceplate above stays true to panel layout; these show the hardware itself.
About the Radial ProDI
The Radial ProDI is a reliable passive DIDirect Injection box — converts an instrument’s unbalanced signal to a balanced mic-level XLR so it can run long cables without noise. box that delivers clean signal conversion at a more accessible price point than the JDI. It uses a custom Radial transformerA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. that handles a wide frequency range and high signal levels without coloring the sound. A practical choice when you need multiple DI boxes for a stage setup without the per-unit cost of premium Jensen-equipped models.
The ProDI is Radial's workhorse passive DIDirect Injection box — converts an instrument’s unbalanced signal to a balanced mic-level XLR so it can run long cables without noise. — the unit you reach for when you need reliable instrument-levelThe in-between signal from a passive guitar or bass pickup — hotter than a mic, quieter than line, and high-impedance. Hence DI boxes.-to-mic-levelThe tiny signal straight out of a microphone — roughly a thousandth of line level. It needs a preamp before anything else touches it. conversion without active circuitry or phantom powerThe +48 V a console sends up the mic cable to power condenser mics and active DI boxes — invisible to gear that doesn’t need it. in the signal path. It sits on stage, not in the rack, converting a keyboard, acoustic guitar preampThe gain stage that lifts a mic’s tiny signal up to line level — the first thing a signal hits, and a big part of how a console sounds., or playback output to a balancedCarries the signal on two wires and cancels whatever noise both pick up — why mic cables can run hundreds of feet hum-free. XLRThe standard 3-pin locking connector for mics and balanced line signals — pin 1 is the shield, pins 2 and 3 carry the balanced pair. signal that can travel clean cable runs back to your console or snakeA multicore cable bundling many channels into one stage-to-console run. A sub-snake collects one corner of the stage into a drop box.. The thru output lets the source also feed a stage amp, so one box covers both directions without splitting anything upstream. At 0.4 kg and no rack footprint, it lives in your DI pouch or tape to the stage.
Passive means zero power draw, zero battery anxiety, and no active failure mode at show time — the transformerA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. either works or it doesn't, and Radial transformers don't quit quietly. The custom transformer handles the wide signal range keyboards and line-levelThe strong signal that runs between pieces of gear (about a volt) — hotter than mic level, far below speaker level. sources throw at it, including hot outputs from digital pianos and playback systems that would clip a cheap passive box. The ground liftA switch that disconnects a cable’s shield at one end to break a ground loop. Lift on DIs and isolators — never on AC safety grounds., standard on Radial DIsDirect Injection box — converts an instrument’s unbalanced signal to a balanced mic-level XLR so it can run long cables without noise., is your first call when a buzz appears at line checkThe quick pre-show pass confirming every input reaches the console, one line at a time. Not a soundcheck — just does it work.. No phantomThe +48 V a console sends up the mic cable to power condenser mics and active DI boxes — invisible to gear that doesn’t need it. required means it's safe to leave on a snakeA multicore cable bundling many channels into one stage-to-console run. A sub-snake collects one corner of the stage into a drop box. feed where phantom state is uncertain.
The ProDI earns its place when you're stocking multiples — keys rig, acoustic, click feed to the drum sub, spare on the truck — and per-unit cost matters across a five- or six-box buy. If you're running a single critical source, particularly an upright bass or passive guitar where transformerA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. character genuinely matters, the Jensen-equipped JDI is worth the premium. The ProDI is not an active DIDirect Injection box — converts an instrument’s unbalanced signal to a balanced mic-level XLR so it can run long cables without noise. and won't fix a weak or high-impedanceOpposition to signal flow, in ohms. Low-impedance IEMs are easier to drive loud; mismatches shift level and tone. passive guitar pickup the way an active unit would. Know your source impedances before you commit.
In the rack
- Keep one ProDI velcro'd inside your monitor rack lid as a spare — no power required means it's ready regardless of what rack position you pull it from.
- For keyboard or playback line-levelThe strong signal that runs between pieces of gear (about a volt) — hotter than mic level, far below speaker level. sources, engage the pad if the source output is hitting the transformerA magnetic coupling that passes audio between two windings with no wire contact — isolates splits and kills ground-loop hum, no power needed. hard; driving a passive transformer into saturation adds low-end bloom that sounds like a problem, not a feature.
- Label the thru output clearly with a strip of gaffers tape — at load-in under stage lighting, a TRSTip-Ring-Sleeve — a 1/4″ jack with three contacts carrying a balanced signal or a stereo pair. A guitar plug with one extra ring. thru and a TRS input look identical, and a mispatched thru will confuse the signal flow fast.
- When deploying multiples, test the ground liftA switch that disconnects a cable’s shield at one end to break a ground loop. Lift on DIs and isolators — never on AC safety grounds. on each unit at soundcheck before doors, not during — ground loopsHum from gear seeing two ground paths at slightly different voltage — the classic buzz when two racks share audio and power. on keyboard submixes with several DIsDirect Injection box — converts an instrument’s unbalanced signal to a balanced mic-level XLR so it can run long cables without noise. in series can be subtle until a synth pad fills the room.
Full-range passive DIDirect Injection box — converts an instrument’s unbalanced signal to a balanced mic-level XLR so it can run long cables without noise. box.
I/O Ports (3)
| Port | Connector | Direction | Signal | Channels |
|---|---|---|---|---|
| Input (TRS) | TRS QUARTER | input | analog audio | — |
| Thru (TRS) | TRS QUARTER | output | analog audio | — |
| Output (XLR) | XLR MALE | output | analog audio | — |
Deciding between two?
Rack space, watts, weight and every connector, side by side.
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