[Elecraft] headphone impedance

[Don Wilhelm]

Steve,

Look closely - that is the *power* that can be developed by the 
amplifier.  Certainly a higher impedance load will reduce the power 
available from the amplifier, but the output voltage will be higher and 
the current requirement is lower.
Most headphones (other than some audiophile types) do not require much 
power at all.

73,
Don W3FPR

On 12/28/2015 1:59 PM, Steve Ellington wrote:
> K3  uses the.
>
> LM4811  Headphone Amplifier
>
> Texas Instruments Specs for output Z
>
> RL = 16Ω 105 mW
> RL = 32Ω 70 mW
>
> At 60 ohms the output power drops to 20 mw. Per their graphs.
>
> 300 ohms is not even considered.
>
>