Step 1 - Choose models

Headphone:

Amp:

Step 2 - Find specs

# Spec data Value Comments
1 Your desired SPL (db) 85 - 110 db (normal to very loud)
2 Headphone Impedance (Ohm)
3 Headphone Sensitivity (dB/mW)
4 Required Headphone Power (mW) Calculated (link)
5 Amp Output Impedance (Ohm)
6 Amp Output Power (mW) Closer to Headphone Impedance
7 THD+N (% or dB) < **0,001% or -100dB - good enough for mixing or mastering
—-
OR
—-
< 0,0001% or -120dB for excellence!**

Step 3 - Verify if we have following conditions:

  1. Headphone Impedance (#2) > Amp Output Impedance (#5) ~8 times

  2. THD+N (#7) < 0,001%

  3. Amp Output Power (#6) > Required Headphone Power (#4) ~8 times

Verdict

Links

https://ctrlcalculator.com/everyday-life/headphone-power-calculator/