sE Electronics DM3 Active Inline DI

The sE Electronics DM3 is a compact active inline direct box for connecting instruments and other high-impedance sources to a microphone-level XLR input. It is designed for guitar, bass, piezo-equipped instruments, keyboards, synthesizers, drum machines, and similar sources. Its inline layout connects directly to a phantom-powered XLR input, avoiding the need for a separate DI box-to-mixer XLR cable.

Its 10 MΩ Ultra-HiZ input is intended to minimize loading on passive pickups and piezo sources. This helps preserve the character of instruments that can sound dull or lose level when connected to lower-impedance inputs. The DM3 also provides a dedicated Class-A output buffer for a stable balanced output feed.

The DM3 accommodates both low-output instruments and higher-level electronic sources. A recessed, switchable attenuation pad provides 15 dB or 30 dB of input reduction when a source is too hot for the connected preamp or mixer input. Its specified maximum input level reaches 49 dBV with the 30 dB pad engaged.

For noise troubleshooting, the DM3 uses a three-position ground-lift switch with Off, On, and On+ positions. The On setting is intended to help break ground loops that cause hum or buzz. The On+ setting is designed to address additional high-frequency noise such as hiss or radio-frequency interference where applicable.

This DI is suited to stage, studio, broadcast, and portable recording systems that provide standard 48V phantom power. Its locking 1/4-inch input helps prevent accidental cable removal during use. The compact cylindrical housing can fit into a small accessory case or pocket and is practical for direct connection to mixers, audio interfaces, preamps, and stage boxes.

Key Features

• 10 MΩ Ultra-HiZ Input: Helps retain the natural response of passive and piezo pickups.
• Class-A Output Buffer: Provides a buffered signal for XLR microphone inputs.
• Switchable Input Pad: Reduces hot input signals by 15 dB or 30 dB.
• Three-Position Ground Lift: Offers Off, On, and On+ noise-management settings.
• Locking 1/4-Inch Input: Helps keep an instrument cable connected during use.
• 48V Phantom-Powered Operation: Runs from a compatible XLR input without batteries.

Design & Installation

The DM3 uses a slim all-metal housing with a tiger-stripe finish and a gold-plated 3-pin male XLR connector. It measures 0.79 inch in diameter and 3.76 inches long, with a weight of 2.47 ounces. Recessed pad and ground-lift switches help reduce unintended setting changes, and the included screwdriver is used to access them.

Connect the instrument or source to the 6.3 mm (1/4-inch) TRS input, then plug the DM3's male XLR output into a mixer, interface, preamp, or stage box that supplies 48V phantom power. Use a balanced XLR microphone cable where an extension is required, and engage phantom power at the receiving input. Start with the pad disengaged, then select 15 dB or 30 dB attenuation only if the source overloads the connected input; use the ground-lift settings only as needed to address system noise.