IRPA MK12 - 1977 N56

The IRPA MK12 is an exceptionally rare Soviet small diaphragm tube condenser from the early 1970s. Less than 150 were ever manufactured. It is essentially the Soviet equivalent of the Neumann KM64, which used the AC701K based tube amp from the KM54 with the KK84 mylar capsule used in the KM84. The MK12 capsule looks virtually identical to the Neumann KK84, and the 6S31B tube is the Soviet equivalent of the AC701K.

IRPA, also known as VNIIRPA, or the Popov Institute for Broadcasting and Acoustics, designed and manufactured high end audio equipment in very small quantities for specialized use. Some of their designs, like the multipattern LDC MK13, were produced by the Oktava factory in larger quantities (250-500). The MK12 was only ever made by IRPA in extremely small quantities with less than 150 ever manufactured. 

The model number MK12 sounds familiar because of the well-known Oktava MK-012, but there are very few similarities other than both being small diaphragm condenser mics made in Russia. Unlike the modern MK-012, the MK12 is a tube mic that uses the 6S31B subminiature tube (a Russian AC701K, also used in the MK13 and LOMO 19a19) feeding a custom hand-wound output transformer. The capsule uses a single-sided 20mm gold sputtered mylar diaphragm that is shockingly similar to the Neumann KK84 capsule, sharing the same dimensions, hole patterns, and musical response that this capsule is known for.

This is an outstanding sounding microphone, and much like its big brother the MK13, is one of the most coveted mics in our studio’s mic cabinet. If you’d like to hear the MK12 used to record a complete song, you can do so by streaming it from the audio player below.

The sample was recorded using MK12’s on every instrument. Three MK12s were used on drums using the Glyn Johns technique with a kick mic, and then a single one for each amp, and two for vocals (one close, one as a room mic). The link in our bio contains an unprocessed stereo mix, as well as individual files for each instrument/mic so you can hear how it sounds on every source, and mix and mess around with it as you please. Everything was recorded at modest levels through our Sphere Eclipse console preamps into a Burl A/D without any processing whatsoever.