S-12 Microphone Kit

$ 359.00

RK-12 capsule

The S-12 is an all-inclusive solid-state microphone kit whose voicing is inspired by the AKG C414.


  • Vocals
  • Acoustic guitars (especially large, full-bodied dreadnought styles)
  • Drum overheads (recommended: build the optional pad switch into the microphone)
  • Orchestras / Ensembles
  • Strings
  • Percussion

Circuit Description

The mic has an internal switch that can be configured at build time as either a Cardioid/Omni polar pattern switch, or as a 10dB pad. All parts for both options are included.

The 3rd-generation transformerless circuit kit incorporates numerous upgrades, improvements, and optimizations. We use audiophile-grade parts throughout the circuit: NOS JFET from Siliconix part, manually biased in our shop for every kit. The bipolar output transistors are NOS parts from Hitachi. The signal capacitors are low-noise, high fidelity parts from Wima. Resistors are 1% tolerance parts from Vishay.

The microphone has high sensitivity -- 35mV/Pa or better -- with low self-noise (<10dBA). It is fantastic on female vocals, drum overheads, or as a main pair for location recording.

If you're interested in the S-12 but need a Fig-8 polar pattern, see the new S3-12 microphone kit, which uses the same circuit but offers 3 polar patterns and a switchable pad.

Recent Reviews

Paul White, senior editor for Sound On Sound Magazine, built an S-12 and concluded that "it could certainly give some of the boutique mics out there a run for their money." That's high praise for a $329 kit.

"A test recording of speech revealed a warm, smooth character without any obvious presence boost... Plenty of HF detail is present, but not in that splashy, in-your-face way that some mics present it, which suggests that it is likely to be kind to female vocals."

Read the full review here.

Here's a video review from Jeannot Kuenzel, with snapshots of the build and a compelling demonstration of the mic's remarkably low noise floor:

How to Build a Microphone

Every kit includes a comprehensive, full-color manual -- 30+ pages of color photographs with arrows and diaphragms and bullet-pointed steps. Customers tell us our documentation is the best they've ever seen.

Nonetheless, we do NOT recommend this as a first-time DIY audio project. Build a stomp box or DI first, or install one of our capsules into an inexpensive condenser. Learn how to solder without spending $300 on a premium microphone kit. And then come back for this -- you won't regret it.

See also this video from one of our customers, Chris Goode, who filmed his entire microphone build on an iPhone and made a video of the result:

Visual Color Choices

The S-12 kit includes a black painted aluminum body with a small diamond logo badge.

If you prefer, you can order one of our custom color finishes instead. (Custom mic body colors cannot be purchased separately; you would have to choose the color and add it to the same shopping cart as the S-12 kit.)

The grille, for all body color options, is a 2-layer brass mesh with satin nickel finish.


What's in the box?

  • S-12 mic body and chassis, pedestal mount for capsule, XLR3M insert, with the necessary screws for assembly.
  • Swivel mount.
  • MP-V57 PCB kit: our custom US-made circuit boards, with 100% of components needed to build the circuit, including pre-cut and tinned OFC silver/teflon hookup wire.
  • RK-12 capsule, with our proprietary "supersaddle" mount and all necessary screws and wires.
  • Full-color, comprehensive installation guide/manual.


Recommended Shockmount

We recommend the Roswell Pro Audio "Cutaway™" shockmount, available exclusively here.


What about matched pairs?

We've sold many matched pairs of the S-12 kit. Just add two of these kits to your cart, and then add the matching option. We will supply your two S-12 kits with a matched pair of RK-12 capsules.

What about Figure-8?

If you are looking for a 3-pattern mic (Cardioid/Omni/Figure-8) with the sound and specifications of the S-12, see the new S3-12 microphone kit.



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