Assembly Guide — Talas One Condenser Microphone

Status: Work in progress. This guide will be completed and validated through fresh rebuilds as part of the open hardware publication process.

Prerequisites

Tools

• Soldering station with fine tip (e.g., Toolcraft ST-100D or equivalent)
• Stereo microscope or magnifying lamp — required for SMD component inspection
• Multimeter with continuity mode
• Oscilloscope (recommended for debugging)
• Tweezers (for SMD placement)
• Solder wire (0.5mm recommended for SMD, 0.8mm for through-hole)
• Flux (no-clean)
• Isopropyl alcohol + brush for cleaning

Components

See the BOM for the complete parts list with sourcing links.

PCBs

Both PCBs can be ordered from any PCB fabrication service (e.g., PCBWay, JLCPCB) using the gerber files in hardware/gerbers/.

Specifications:

• 2-layer PCB
• 1.6mm thickness
• HASL finish
• Standard FR4

Assembly Order

Step 1 — Preamp Board

1. Start with SMD components (OPA1642AIDR op-amp)
2. Then through-hole resistors and capacitors
3. Finally connectors

Step 2 — Hex Inverter Board

1. SMD components (TC4584BF)
2. Through-hole passives (resistors, capacitors, diodes)
3. Connectors

Step 3 — Mechanical Assembly

1. Mount both PCBs in the microphone body
2. Connect inter-board wiring
3. Connect capsule leads
4. Close body (standard screwdriver — no glue)

Step 4 — Testing

1. Connect XLR cable to audio interface with 48V phantom power
2. Verify bias voltage with multimeter (~60V DC expected)
3. Check preamp output with oscilloscope
4. Audio test in DAW

Debugging

If the microphone produces no audio output, follow this systematic approach:

1. Visual inspection — Check all solder joints under microscope for bridges or cold joints
2. Continuity test — Verify all connections match the schematic netlist
3. Voltage rails — Measure phantom power delivery (48V), bias voltage (~60V), and preamp supply
4. Signal tracing — Use oscilloscope to follow signal from capsule through each stage

See also the hex inverter test guides in hardware/hex-inverter/ for board-specific testing procedures.