The Kopul stereo multimedia passive direct box provides a practical connection between consumer-level or instrument audio sources and professional mixing consoles, microphone inputs, and PA systems. Its passive two-channel design requires no batteries, phantom power, or external power supply.

Two 1/4-inch tip-sleeve inputs accommodate electric guitars, basses, keyboards, and other instruments. When only one 1/4-inch input is used, the unused connector can function as a parallel output for routing the instrument signal to an amplifier while sending a clean direct signal to a mixer or recording system. The two inputs can also support two instruments or stereo keyboard signals when used with a suitable insert Y-cable.

A stereo 3.5mm input connects smartphones, tablets, portable media players, and computers. A pair of RCA inputs supports turntables, computer sound cards, receivers, DVD players, DJ equipment, and other consumer or A/V sources. Two balanced three-pin XLR outputs route the left and right channels to a mixing console or PA system.

Custom-wound isolated transformers convert high-impedance unbalanced signals to low-impedance balanced audio while helping suppress hum and buzz caused by ground loops. The transformer design provides a warm, natural response across a 20 Hz to 18.5 kHz frequency range and supports a 128 dB dynamic range for handling strong audio signals.

A switchable -15 dB attenuation pad reduces levels from loud guitars, keyboards, and other high-output sources. The ground-lift control helps resolve ground-loop noise in stage, studio, installation, and live-sound setups. A heavy-duty aluminum housing provides durable protection for recording, touring, and regular professional use.