Detail 01
Passive, no power needed
Works with no battery and no phantom power, so it never dies mid-set and stays quiet.
Product detailSKU #1274228072038
Radial EngineeringJDI MK3 Passive Direct Box
1/6
Independent shopping perspective
The Korena take
Passive transformer direct box for bass, guitar and keyboards. Needs no power, handles hot signals, and survives road use. A studio and stage standard.
Strong match
Who this is for
- Bass players sending a clean signal to the console alongside their amp
- Stages with no phantom power available at the input
- Hot outputs like an amp speaker feed that would overload an active box
Consider the trade-offs
When to look elsewhere
- Low-output passive pickups needing the extra gain an active box provides
- Anyone who wants the absolute lowest cost DI for occasional home use
- Sources already balanced and at line level
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
+19dB maximum input level
Takes very hot signals without distorting, so an aggressive bass or a speaker-level feed will not overload it.
Detail 03
10kΩ input impedance
High enough that it does not load down a pickup, keeping high end and note attack intact.
Detail 04
600Ω output impedance
Matches what a mic preamp expects, so the signal travels long cable runs to the console without loss.
Detail 05
10Hz to 40kHz frequency range
Extends well below the lowest bass note, so low B fundamentals pass through without thinning out.
Detail 06
Welded steel, baked enamel
Survives being stepped on and thrown in a road case. Enamel resists chipping better than paint.
Final check
Know before you order
- 01XLR cable to the console is not included
- 02Two 1/4 inch inputs; check your source uses that connector
- 03Passive design does not add gain, so quiet pickups may need preamp trim
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01Does the JDI MK3 need phantom power?
No. It is a passive transformer design, so it needs no phantom power and no battery. Plug it in and it works, which makes it reliable on stages where power is uncertain.
02Passive or active DI for bass?
Passive suits active basses and hot outputs, since it takes up to +19dB without distorting. Passive pickups with low output sometimes benefit from an active box's gain instead.
03Can I run a speaker output into it?
The +19dB maximum input handles very hot signals, which is why players use it for aggressive sources. Check the level against that limit before connecting anything amplified.
04Will it work with keyboards?
Yes. Two 1/4 inch inputs accept keyboards, bass and guitar. The wide 10Hz to 40kHz range and 0.1dB linearity keep the signal clean.
Reference
Full specifications
The complete catalog record, organized around the decisions musicians make when comparing gear.
1 detailsSound
- Frequency Range
- 10Hz40kHz
3 detailsBody & build
- Body Finish
- Baked enamel
- Construction
- Welded steel
- Finish
- Baked enamel
5 detailsConnections & power
- Input Impedance
- 10kW
- Output Impedance
- 600W
- Output Connectors
- XLR male
- Maximum Input Level
- +19dB
- Input Connectors
- Two 1/4 inch phone
5 detailsOther
- Distortion At 20hz
- 0.006%
- Phase Coherence
- 4 degrees at 20Hz
- Dynamic Range
- 135dB
- Linearity 2020khz
- 0.1dB
- Signal to Noise
- 119dB
