Multitrack Microphone Circuit Kit

We have revised and improved the multitrack circuit kit. It is not yet available for DIY, but its release would be accelerated if customer demand warrants it. We do have fully built multitrack microphones available for purchase as well; send an email for details.

This kit creates a large-diaphragm condenser microphone that allows you to choose the polar pattern at mix time. It has separate outputs for the front and rear halves of the capsule; by recording both to independent tracks, you can control the effective polar pattern after tracking is complete. (See the mix matrix below.)

The circuit is our acclaimed transformerless design, implemented with high-grade parts. The circuit incorporates a next-generation corrective EQ option to adjust the mic's high-frequency response and smooth the mic's response.

The finished mic has high output (~35mV/Pa), low noise, low distortion, and a very smooth (not bright or harsh) response. It is suitable for voices, acoustic instruments, foley, and ensemble miking.

In The Box

This kit contains two separate circuits, a 5-pin XLR insert, and a detailed build/installation guide.

The donor mic, capsule, and XLR5 breakout cable are not included in this circuit kit. See the Requirements section below.

From time to time we have original MXL 920 donor microphones on hand, available for bundling with the circuit kit at or below the price we paid for them (generally $90-$110). These include the swivel mount that originally accompanied the microphone, but might have minor cosmetic flaws on the mic body or grille.

Compatibility / Requirements

These PCBs fit the MXL 920. They are not known (and not likely) to fit any other microphone.

This mic requires the MicParts RK-87 capsule, which has two independent capsule halves and electrically isolated backplates. The capsule is not included with the circuit kit; order it here.

You will need a breakout cable, with a 5-pin female XLR connector on one end, and two 3-pin male XLR connectors on the other. Here's an inexpensive one from Amazon (~$15), or a nice one with Mogami cable and Neutrik connectors from B&H (~$50).

Optional Upgrades

The modified MXL 920 is compatible with the Rycote USM-VB, which we use and recommend.

We made custom die-cut foam that puts the USM-VB and multitrack microphone into the world's best microphone case, the SKB iSeries 1209-4; see details on the SKB microphone case page.

Skill Level

This kit is comparable in difficulty to the MP-V57 or any of our other transformerless circuit kits (although, technically, this kit contains two of them).

We do not recommend this kit for people who have never soldered before, nor for first-time mic builders -- see the S-25 kit instead.

Mix Matrix