S-12 Microphone Kit

$ 339.00

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

You can choose from a satin black anodized finish or a matte green powdercoat. Both are tough, integrated finishes that resist fingerprints, scratches, dents, and dings.

The powdercoat options costs a bit more because we actually bead-blast the black finish away, mask the body, and apply a 2-stage powdercoat, followed by careful sanding to ensure proper shielding for the circuit.

Please note that the powdercoat colors are applied in small batches. We frequently sell out of these, and do not consistently update availability on the website. If you order an option that is not immediately available, we will notify you via email.

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

What's in the box?

  • The unbranded mic body kit includes an anodized aluminum body sleeve and end cap, mic chassis, capsule deck, domed pedestal mount, brass mesh grille, and pre-wired XLR3M insert. We provide M2 metric machine screws for mounting the circuit boards.
  • Swivel mount. (See our shockmount options)
  • 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.

We carry an inexpensive shockmount designed to fit this microphone.

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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