DAC Calculator — Output Voltage, Dynamic Range & Headphone Drive

Most USB DACs output 2V RMS (the Red Book CD standard). High-end DACs may output 4-5V RMS. Phone headphone outputs typically max at 0.5-1V RMS. Desktop DACs like the Schiit Modi or Topping D10s output around 2V RMS.

Dynamic range is the difference between the quietest and loudest signal a DAC can reproduce. The theoretical limit is 6.02 × (bit depth) + 1.76 dB, so each bit adds about 6 dB. Using the full formula, 16-bit gives 98.1 dB and 24-bit gives 146.2 dB (this calculator uses the full 6.02N + 1.76 figure; the common "96 dB / 144 dB" shorthand simply rounds to 6 dB per bit). In practice, DAC analogue circuitry limits real-world dynamic range to about 120 dB for good DACs; the very best measure near 130 dB.

Many DACs have a headphone output with a built-in amplifier. The DAC line output alone (without amplification) can drive high-sensitivity, low-impedance headphones and IEMs, but may lack current delivery for demanding headphones. Check both voltage and current capability.

If the DAC cannot deliver enough voltage or current for your headphones at your desired volume, yes. High-impedance headphones (250+ ohms) need more voltage. Low-impedance planar magnetics need more current. Most IEMs are fine from a DAC headphone output.