Quieting headphone pop: Would it work to put a discharge resistor in a custom dongle?

Question

When I leave my favorite headphones connected to my favorite smartphone or laptop when I'm not currently playing any audio, I periodically hear a small pop/click/crackle. I suspect it happens when some process "opens the headphone port", even if they don't immediately start playing audio.

Please note that I don't get any pop/click/crackle at other times, no matter how much I rotate or wiggle the plug or cord; so I have no reason to suspect flaky connections of any kind, such as dirty connectors, broken wires, etc.

I saw this answer to a similar question…
Loud pop noise while plugging to a headphones jack
…and I wonder if that applies to my situation.

I'm wondering if the small pop I hear might have the same root cause (charging a DC decoupling capacitor). I'm also wondering if I could implement the proposed solution — wiring a ~100Ω resistor from line to ground — in an external dongle I would place inline between my headphone cord and my audio source device.

Answer 1

I'm also wondering if I could implement the proposed solution — wiring a ~100Ω resistor from line to ground — in an external dongle I would place inline between my headphone cord and my audio source device.

You've missed the grand fallacy of this idea: there is already a much more significant 8 to 32 Ω across the output if the headphones are already plugged in. The 1000 Ω in parallel won't make any difference.

^{simulate this circuit – Schematic created using CircuitLab}

Figure 1. The problem this time is that the amplifier or pre-amplifier is being enabled in the device hardware.

On turn-on the amplifier output jumps to V+/2 and so does the right side of C1 until discharged by the speaker. The pulse is what you hear.

Sorry, I don't have a solution for you.