The Manley Labs Reference Cardioid (commonly known as REF-C) is a large-diaphragm tube microphone offering a wide, 10 Hz to 30 kHz frequency response and accurate transient performance without coloration or any perceivable sonic signature. The rich tonal balance and liquid character make this center-fixed cardioid mic an excellent choice for obtaining a very forward, immediate sound when recording acoustic guitars, drum overheads, saxophones, and especially pop vocals and voiceovers—with a "finished" sound right out of the box.

The Reference Cardioid features a 1" gold-sputtered diaphragm that is 6 microns thick based on the vintage U47. It has the ability to withstand sound pressure levels up to 150 dB. The open-weave stainless steel grille allows the capsule to capture signals with zero-loss acoustical transmission, which translates to less dampening of high-frequency content.

The electronics of the Reference Cardioid include two triodes in cascade forming an entire gain-block. The dual-triode 12AX7 tube is easily obtainable and was chosen for its high gain and low noise properties. The audio signal and power connect from the microphone to the filtered B+ power supply via a single 30', 6-pin XLR cable. The audio output exits the power supply via 3-pin XLR through a custom-wound output transformer, which employs nickel laminations and "humbucking" bi-filar windings, all enclosed in mu-metal.

The REF-C features a proprietary suspension system that is attached to the black & red anodized casing. The capsule itself is mounted to a neoprene-rubber shockmount to prevent unwanted vibrations from being picked up by the diaphragm. Handmade in the USA, the microphone ships with a leather capsule cover, locking carrying case, and IEC power cable.