OQAN QDI-400 STEREO - Passive Stereo Injection Box
The OQAN QDI-400 STEREO is a passive, two-channel direct injection (DI) box designed to be an essential and reliable tool both on stage and in the recording studio. Its primary function is to convert unbalanced, high-impedance audio signals, such as those from keyboards, electro-acoustic guitars, basses, or audio players, into balanced, low-impedance signals. This process is crucial for sending sound over long cable runs without loss of quality and, above all, without introducing unwanted noise and interference. Thanks to its passive design, the QDI-400 requires no batteries or phantom power, offering a robust, always-ready plug-and-play solution. Its heavy-duty metal chassis ensures exceptional durability, withstanding the demands of continuous use on tours and live performances.
Main Features
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Stereo/Dual Mono Operation: Equipped with two independent channels, it allows processing a stereo signal (such as from a synthesizer or music player) or two different mono signals simultaneously.
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Professional Inputs and Outputs: Each channel has an unbalanced 1/4" (6.35 mm) jack input for connecting instruments and a balanced XLR output for sending the signal to a mixing console or audio interface.
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Three-Position PAD Attenuator: Features a three-position attenuation (PAD) switch (0 dB, -20 dB, -40 dB). This function allows you to handle sound sources with very high levels, preventing saturation and distortion at the mixer's preamp input.
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Ground Lift Switch: Includes a ground lift switch that helps to effectively eliminate hum and background noise caused by ground loops, a very common problem when interconnecting different electrical equipment in the same sound system.
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Robust Construction: Its all-metal casing is designed to withstand shocks and wear from intensive use, protecting the internal components and ensuring a long service life.
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Passive Design: Requiring no external power, it is an extremely reliable and easy-to-use tool. Simply connect the cables and it's ready to operate in any situation.
Benefits for Musicians and Sound Technicians
The OQAN QDI-400 STEREO is the ultimate solution for ensuring a clean, powerful, and interference-free audio signal. For musicians, this means their instrument's tone will reach the mixing console perfectly, regardless of the distance. For sound engineers, it's an indispensable tool for quickly and efficiently resolving noise issues and matching the impedance of various audio sources. Its versatility makes it perfect for stereo keyboards, guitars, basses, DJ equipment, and any line-level source that needs to be connected to a professional sound system.
Use Cases
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Live Musicians: Ideal for connecting keyboards, synthesizers, electro-acoustic guitars or basses directly to the PA system, ensuring a clear and noise-free sound.
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Recording Studios: Perfect for recording instruments with line output, adapting the signal to enter cleanly into the audio interface or recording console.
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DJs and Producers: Allows you to connect DJ controllers, samplers or laptops to professional sound systems safely and without buzzing.
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Sound Installations: A fundamental tool in theaters, conference rooms and churches to adapt audio signals from computers, projectors or other multimedia devices.
Frequently Asked Questions
Does it need batteries or an external power source to operate?
No. The OQAN QDI-400 is a passive DI box, meaning it doesn't require any power supply, batteries, or phantom power. It operates using internal transformers that balance the signal.
What is the "Ground Lift" switch for?
The "Ground Lift" switch breaks ground loops, which are a common cause of 60 Hz hum. If you hear a hum when you plug in your equipment, flipping this switch usually solves the problem.
When should I use the attenuator (PAD)?
The attenuator is used when the input signal is too "hot" or strong and causes distortion in the mixing console. It starts at 0 dB, and if the signal saturates, try -20 dB. For very high-gain sources, such as the output of an amplifier, the -40 dB setting is appropriate.
Can I connect an electric guitar directly?
Yes, you can connect an electric guitar or bass, although passive DI boxes can slightly affect the tone of passive pickups. For best results with guitars and basses, it's recommended to use it after effects pedals or from the line output of a preamp.
Project description
Two-channel passive direct injection box. It features two unbalanced 6.35 mm jack instrument inputs and two balanced XLR line outputs. Each channel includes a selectable pad with 0 dB, -20 dB, and -40 dB settings. A ground lift switch is included for hum and noise reduction. The chassis is constructed of metal for maximum durability.
