Mic Mods

The common term for what I do is mic mods — but that’s not quite accurate. What I actually do are full rebuilds: I completely gut the mic and replace everything inside. Still, if I called them mic rebuilds, the search engine gods would leave me in the dust and you wouldn't be reading this right now. So, mic mods it is!

I rebuild low-cost large diaphragm condenser (LDC) and small diaphragm condenser (SDC) mics from brands like MXL, Sterling, M-Audio, and others. Custom imported bodies are also in the mix. I work with both transformerless (TL) and transformer-coupled (TC) circuits — with a particular passion for the character and sound of the transformers.

Want more of the story? Read on. 🎙️ Or skip all that and have a look around the store 🎙️

The Circuits

I build two flavors of microphone circuitry: Transformerless (TL) and Transformer-Coupled (TC). The original TL board is called the jaSb (just another Schoeps board). Like nearly every other low-cost TL mic, it's inspired by the elegant Schoeps CM5 circuit— adapted here for a large diaphragm capsule. It has very fast transient response and very low noise.

mxl mic mod — Stock MXL surface-mounted board (L) and the jaSb

Next came the Transformer Coupled circuitry. This is modeled after the Neuman KM-84 circuit again adapted for LDCs. I call it the BFM (Big F'n Microphone). These days, I am mostly doing TCs. I generally prefer the harmonic richness and simplicity of the circuit. Like the jaSb, the BFM features discrete high quality components, Point to Point capsule wiring and hand-selected biasing resistors. There have been many adaptations of the BFM for different mic bodies and some of them support external Pad and Filter switches (like for the MXL770/990s, MXL5000, Sterling ST55)

The Capsules

The two capsule types I mostly deal with are k47-style center-terminates and CK12-style edge-terminated. The k47 is a more mid-forward full tone, while the CK12 has a more extended and silky top-end. I will only put k47s in the TL mics but either works wonderfully in the TC builds.