How to Choose a Multimeter for Audio DIY Projects

Key features to look for

1. Low Voltage Accuracy

Why: Measuring the output voltage of a mic or setting an offset to 0, you will need good precision in the millivolt range.

Look for: 0.1mV or 0.01mV resolution and good accuracy (±0.5% or better).

2. True RMS

Why: Accurately measures AC voltage and current in audio signals, especially if they're not perfect sine waves. True RMS multimeters are generally of better quality and operate in a wider frequency range.

Look for: “True RMS” explicitly in the specs.

3. High input impedance

Why: Prevents loading down the circuit, especially in high impedance circuits like tube circuits.

Look for: Input impedance of 10MΩ or higher.

4. Capacitance measurement

Why: Useful for checking caps, when the marking is not clear, sometimes with no marking at all.

Look for: Capacitance range that can go down to picofarads and up to microfarads.

5. Continuity Tester

Why: For checking solder joints and traces, audible beep helps a lot.

Look for: Instant response time (some cheaper meters have annoying delay).

6. Diode Test Function

Why: Usefull for checking diodes and transistors.

Look for: Should be able to test forward voltage drop.

7. Get good test leads

Why: You will need sharp probes and thin clip-on's which will avoid creating short-circuits with the next component. These can be purchased separately.

Optional but Nice-to-Have Features

• Direct voltage measurement in dB: Very convenient for setting up compressors.
• Transistor Tester (hFE): For BJT gain matching in analog circuits.
• Backlit Display: Helps in low-light bench environments.
• Auto-ranging: Speeds up your workflow.

Final Thoughts

Your multimeter is your audio lab sidekick. It should be precise, reliable, and easy to use.

If you plan moving forward in DIY, avoid the cheapest products. Your multimeter is an investment you will use for decades.