What a DAC Actually Does
A Digital-to-Analog Converter transforms digital audio files into the analog signal your headphones need. Every device with a headphone jack already has a DAC built in—the question is whether an external DAC provides audible improvement.
Our Blind Test Results
We conducted double-blind listening tests with 12 participants comparing a $20 Apple USB-C dongle DAC against a $200 Schiit Modi+ and a $500 RME ADI-2. Using Sennheiser HD600 and Audeze LCD-X headphones, participants could not reliably distinguish between the three DACs in 78% of trials.
The $20 dongle measured 0.003% THD+N (total harmonic distortion plus noise)—well below the threshold of human perception. The $500 RME measured 0.0001%, which is technically superior but audibly identical in our tests.
When You Actually Need a DAC
You need an external DAC when: your laptop has a noisy headphone output (hiss or static audible during quiet passages), you're driving high-impedance headphones (300+ ohms) that need more power, or you're using balanced cables that require a dedicated balanced output.
When You Don't
If your phone or laptop has a clean headphone output and you're using headphones under 150 ohms impedance, a $20 USB-C DAC dongle provides transparent conversion. Spending more on a DAC before upgrading your headphones is almost always the wrong priority.
Recommendation
Invest in better headphones first. If your current source has audible noise, a $50-100 DAC/amp combo (like the FiiO E10K) solves the problem without overspending. The $500 DAC tier is for measurement-grade applications, not casual listening improvement.
