How do I convert the gain of an amplifier from volts per volts (v/v) into dB for an audio amplifier?

Sometime the gain of an amplifier is stated in v/v and can be easily converted to dB with the following equation:

V(dB) = 20 log (V₂/V₁)

Example: TPA2032D1 has a gain of 2 v/v, the gain in dB would be 6dB

V(dB) = 20 log (V₂/V₁) = 20 log 2 = 6 dB