Tweakers' Asylum

Headphone output protection circuitry failure.

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The protection circuitry of a headphone amplifier seems to have sacrificed itself for the sake of the pair of low-impedance cans, from what appears to be excessive DC offset at the output while being driven very hard by a high-output source component with no output coupling capacitors during a demanding pro audio session (my bad).

The problem is, the headphone amplifier no longer provides an output signal, but the indicator light is illuminated when the device is powered-on. I powered-off the device for 24 hours to see if the protection circuitry might recover, but it's a no-go. Wondering if the chip, relay, or a resistor or two of the protection circuitry might need to be replaced.

Another option is to be more careful next time, and do without the protection circuitry altogether by wiring the headphone output jack without it, perhaps with better sound as a result. Not a good idea for a pro audio application, but maybe the headphone amplifier can at least be "put out to pasture" so to speak, for a less-demanding home audio application.

Maybe someone can provide tips on how to re-wire the headphone output without the influence of the protection circuitry. TIA



Edits: 07/12/20   07/15/20

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