06-01-2025, 06:10 PM
I've seen opto-couplers used for AV applications. To get acceptable linearity for the audio side, you need a second opto-isolator incorporated into the negative feedback loop of the op-amp driving the LED. You can get opto-couplers with an extra transistor to make this even easier (e.g. IL300).
I seem to recall a project published in Television magazine doing this. No idea how good the results would have been.
Many of the sets I've seen that use an audio transformer for headphones use a class A output stage, running a single transistor from a relatively high supply rail, and using the transformer to convert the impedance to drive the loudspeaker. Not a bad approach, all things considered.
I seem to recall a project published in Television magazine doing this. No idea how good the results would have been.
Many of the sets I've seen that use an audio transformer for headphones use a class A output stage, running a single transistor from a relatively high supply rail, and using the transformer to convert the impedance to drive the loudspeaker. Not a bad approach, all things considered.
