OPA/Bias Generator Combo - Dual Channel

Product Overview

The Dual Channel OPA/Bias Generator Combo is a complete front-end electronics solution designed for DIY condenser microphones. Made for builders and experimenters, it provides an ultra-low noise signal path, and an integrated capsule bias supply. It functions as both a microphone bias generator and impedance converter, making it ideal for custom mic circuit designs.

Ideal for DIY microphone builds, this product helps simplify wiring and installation.

Key Features

• Dual-channel OPA-based microphone circuit
• Integrated bias generator for condenser capsules
• Low-noise impedance conversion

Applications

• DIY condenser microphone builds
• Microphone upgrades and modifications
• Custom audio electronics projects

Technical Description

This compact PCB provides a complete front-end electronics solution for DIY condenser microphones. Built around a low-noise OPA-based impedance converter, the circuit adds only about 1 dB of self-noise beyond the capsule, ensuring the microphone’s noise performance is determined by the capsule itself rather than the electronics.

The board integrates a charge-pump capsule bias generator, balanced output driver, and a switchable capsule padding capacitor for high-SPL applications. Designed specifically for builders and experimenters, it dramatically simplifies the electronics required to create high-performance custom microphones, requiring only five solder connections to complete a microphone build.

• Ultra-Low Noise Signal Path
  The OPA-based impedance converter adds approximately 1 dB of self-noise, allowing the capsule to define the microphone’s noise floor rather than the electronics.
• Integrated Capsule Bias Supply
  An onboard hex inverter charge-pump bias generator provides stable polarization voltage for condenser capsules, eliminating the need for external bias circuitry.
• Complete Front-End on a Single PCB
  Combines impedance conversion, bias generation, and output stage into a compact, builder-friendly design.
• Designed for Modern DIY Microphone Projects
  Compatible with a wide range of condenser microphone capsules and optimized for low distortion, balanced output, and strong RF immunity.

Specifications

Helpful Pairings

This product may be used with our TSC-1, JLI-CK12, and JLI-RK47 depending on your application.

Frequently Asked Questions

What does this circuit do?
This board provides both capsule bias voltage and impedance conversion for condenser microphone designs, simplifying DIY builds.

What type of microphones is this used for?
It is designed for use with condenser microphone capsules in custom or modified microphone builds.

What other components are required?
A condenser capsule, microphone body, and supporting hardware are typically required to complete a build.