with a popular choice being headphone amplifiers that use a tube as a gain stage followed by an op-amp as a buffer with a low impedance output. This forms the basis of [Ratti3]’s amplifier ...
Some are you are probably wondering how the M15c is only $129 USD when it offers such a good DAC, 4 SiP modules, 3.5mm and ...
At the extreme budget end of tube audio lie single-tube amplifiers ... to transform the high impedance output from the tube into a low impedance suitable for driving a headphone or speaker.
For example, a lot of audio equipment doesn’t have a dedicated headphone amplifier that’s tailored ... All headphones and earphones have an impedance rating and whatever that is requires ...