MXL 992 Circuit Mod Kit

This DIY kit is no longer available. If you own an MXL 992, we can upgrade it for you. See the MXL 992 Upgrade Service.   The MXL 992 is an older and slightly better-made version of MXL's standard transformerless condenser mic. But it suffers from a few critical problems: The JFET has much too high an input capacitance figure for this circuit. The JFET is not biased properly to minimize distortion. In addition, critical signal-path capacitors are no-name film types, or worse, non-NP0 ceramic. The latter can cause microphonic noise in the audio signal. We have cooked up a "mini mod" that addresses all of these problems. It includes a selected, ideally biased JFET, with 1% tolerance bias resistors. It includes premium Wima film capacitors for the audio signal path. It replaces the generic thick film 1G resistor with one that is lower in noise and better suited to audio.   Circuit Mod Benefits Expect these benefits from this circuit modification: Higher sensitivity Lower noise floor L