AKG P820 Tube Multipattern Condenser Microphone

AKG P820 Tube Multipattern Condenser Microphone

The AKG P820 Tube is a multipattern tube condenser microphone built around a dual one-inch diaphragm capsule and ECC83 dual-triode circuitry, the combination that gives tube microphones their characteristic warmth and gentle harmonic colour. A separate remote control unit powers the microphone and selects between nine polar patterns, from omnidirectional through cardioid to figure of eight, so one microphone can cover lead vocals, instruments, ensembles and room pickup in a controlled studio. A spider shock mount and metal carrying case are included.

Key features

• Dual 1-inch diaphragm capsule with ECC83 dual-triode tube circuitry
• Nine polar patterns, selected on the remote control unit
• Frequency response of 20 Hz to 20 kHz and 20 mV/Pa sensitivity
• Maximum SPL of 135 dB, rising to 155 dB with the -20 dB pad
• Switchable bass-cut filter at 80 Hz, 12 dB per octave
• Low self-noise of 16 dB-A for quiet sources

Tube circuitry and the dual capsule

Two one-inch diaphragms sit back to back in the capsule, and mixing their outputs in different proportions is what creates the nine patterns. The ECC83 dual triode in the circuit adds the even-order harmonic emphasis listeners describe as tube warmth, and remains easy to replace decades from now. With a sensitivity of 20 mV/Pa, a signal-to-noise ratio of 78 dB-A and self-noise of only 16 dB-A, the P820 Tube captures quiet detail cleanly, while its 135 dB maximum SPL, or 155 dB with the pad engaged, keeps loud sources such as brass, guitar amplifiers and close drums under control.

Nine patterns from the remote

Pattern selection happens on the remote control unit, not on the microphone body, so the engineer can change pickup without walking to the microphone or disturbing its position. The nine steps run continuously from omnidirectional, which hears the room evenly, through the cardioid family to figure of eight, which hears front and back while rejecting the sides. The same unit carries the -20 dB attenuation pad and the 80 Hz bass-cut filter, which removes rumble and tames the bass build-up of close-miked vocals, plus a ground-lift switch for breaking hum loops.

Power and connection

The P820 Tube does not run from mixer phantom power. The microphone connects to its remote control unit with the dedicated seven-pin cable, the unit powers the tube circuit and provides the balanced three-pin XLR audio output that feeds the preamp or interface, and its mains voltage is selectable between 110 to 120 V and 210 to 240 V. Allow the tube a short time to warm up and stabilise after switching on before judging levels or tone. The microphone itself measures 212 x 54 mm and weighs 765 g, so a sturdy stand is appropriate, with the included spider shock mount isolating the capsule from stand-borne vibration.

In session

AKG positions the P820 Tube for professional and project studios, and its pattern choice makes it a genuine one-microphone solution: cardioid for a lead vocal with a pop filter, a wider pattern for a small ensemble, figure of eight for a duet or for mid-side experiments, omnidirectional for a good-sounding room. Vocals, brass, electric guitars and drum overheads are its stated applications. It rewards a treated, quiet space, because a multipattern tube microphone hears the room as faithfully as it hears the performer.