Yanking/removing headphones off amps before turning it off?

[Zerviscos]

Correct me if I'm wrong, but I think I can understand how yanking/removing cables while the amp is on can short the drivers causing a channel imbalance. I was curious about this because I planned to buy the Elex and while I was reading about the Elex having driver issues from clipping at high volumes, I read another instance where someone accidentally yanked his right channel cable causing the voice coil to die.

I was wondering however, if to some extent can a headphone's qc/build quality be so poor that doing this just a few times, be it accidental or not, can cause drivers to actually fail? And is this limited to just the either channel cables being individually pulled away, or if I remove the entire cable from the headphone jack while the amp is on, can still affect driver degradation? This also makes me wonder about leaving the headphone cable on the amp before turning it on will be alright, even with the mute relays. I've read about the issue with the Schiit Asgard before, but I've never really thoroughly read it.

My amp, the LakePeople G109-A seems to have a protective relay that came from the G109-P, I don't know however if it's just the delayed-on/quick-off 'pop-elimination' circuit though, but I have on a few times, removed my HD6XX and HD600 from it on purpose, and probably once or twice accidentally, with no issues while it's on and left it there as well.

Also I'm thinking of switching to the S.M.S.L. SP200 THX888 Amp because of the upcoming M400/200 DAC. I was wondering if this has enough protection features to atleast lessen any potential future issues I can have with driver issue, or really anything at all. 'Cause even if I'm careful, I can't really promise myself I won't be doing any accidental pulling and stuff and whatnot, especially when a cable is so short but just slipped my mind , and I don't want a probably first accidental pull on a new headphone to also be the first time it dies.

 

[Bob-23]

My amp, the LakePeople G109-A seems to have a protective relay that came from the G109-P, I don't know however if it's just the delayed-on/quick-off 'pop-elimination' circuit though, but I have on a few times, removed my HD6XX and HD600 from it on purpose, and probably once or twice accidentally, with no issues while it's on and left it there as well.

Well-done muting circuits have (at least) a double function: delayed turn-on/quick turn-off in order to protect the headphones against switch-on/-off voltage spikes, and, second, shuting-down the headphones (-out) immediately in case of a 'dc-accident' (e.g. failing opamp) within the amp that could potentially destroy your headphones.

I can't see how removing a headphone from the amp could damage the headphones - it might damage the amp if the plug is only partly drawn out, thus, maybe shorting the amp's headphone-out. The amps' output stages' opamps often have short circuit protection built-in, at least, for 'short shorts', and an output resistor can add an additional layer of short circuit protection, so that the amp always sees a load, even when shorted - but this comes with a price: output impedance increases. (If you want to be completely on the safe side in that regard: turn down the volume before plugging out the phones, some amps even have a separate switch by which you can manually mute your phones.)

The cables may break by physical stress when removing headphones.

 

[Fluffy]

Don't know about damaging drivers. I had a few times when I inserted (or pulled out) the headphone plug half way in while the amp was on and there was music playing, and it gone into some protection mode that required a reset (the amp is Arcam rHead). The manual says it happens when there is a DC offset detected. I suppose that an amp without this kind or protection can lead to trouble. Anyway, I think it's advisable to plug in or remove the headphone jack only when the sound is muted, and make sure it's inserted all the way in, to avoid these issues.

If you're so afraid that you'll yank out the cable without noticing, you can make some sort of a safety loop, like wrapping the cable around something else before its termination point at the amp. My amp just sits on the desk, so after connecting the cable to the amp I wrap it around the back side of the amp with some slack left, so if I pull on it, it has some amount of give before it yanks the plug out.

 

[maverickronin]

There's a couple different things here. That Elex on reddit sounds like a mechanical issue with the jack/wiring on the ear cup. He says the voice coil is burnt, but it just looks like adhesive to me. Also, removing the connector from the headphone cup wouldn't put any extra power through the voice coil so it doesn't make sense that it would burn up either.

Second would be amp putting too much power into headphone through something like turn on/off thump or DC offset. With today's high power headphone amps it easily possible for this to destroy a driver and that's on the amp manufacturer. Schiit's earlier amps used to do that quite a bit.

As for unplugging the headphones from the amp while something is playing that is more likely to be dangerous to the amp than the headphones. TRS connectors were never designed to carry that much power and can actually short circuit the amplifier when unplugged so amps without any overcurrent protection could potentially burn up their output transistors.

If you're concerned about that it would be best to research the individual amp and make sure the manufacturer has addressed the issue in their design. It's often assumed that any reputable manufacturer has, (i.e. how Amir pretty much just measures the audio performance and occasionally comments on grounding issues or something) but that's not always the case.

The common things to look for would be making sure that startup thump is addressed, either by output relays or being intrinsically low power. The second would be a "DC servo" which is a circuit that continuously monitors and adjusts the amp's DC offset.

Of course there are endless way one could design circuit so something don't necessarily need to follow those guidelines to be safe. The same results could be achieved in other ways.

 

[Bob-23]

Lake People in Konstanz don't have your amp anymore; headfi says: "Outputs with relais controlled switch-on delay" - so apparently no dc-protection, as with so many amps. (If you were a diyer: there's a relatively simple but very intelligent circuit - switch-on delay & dc-protection - by which you might extend your amp, components 10 Euro, built it twice, works perfectly!)
(Are there output capacitors in your amp, big electrolytics?))
And, btw, I'd stay with your amp, be happy that you've got a 'Lake people', they have a good name here.

 

[direstraitsfan98]

If it's anything like unplugging the speaker terminals from an amp I think the issue you have is having the positive terminal touch the negative terminal and if you do that I've found speakers go crazy and will 'pop' and the driver tends to pull its maximum excursion. Probably not healthy at all.

 

[A800]

Jack plugs do have inherent design weaknesses.

 

[Bob-23]

Finally tested it (yes, we have time, nowadays...): When pulling out the headphone plug, it's unavoidable that you short - at least for an instance - right and left channel. But there was no short to ground which I originally thought we'd have - and that would be the ('dangerous') problem described above. (Yes, we should test your hypothesis before reproducing them.)

 

[Zerviscos]

Thanks for the response guys.

If you're so afraid that you'll yank out the cable without noticing, you can make some sort of a safety loop, like wrapping the cable around something else before its termination point at the amp. My amp just sits on the desk, so after connecting the cable to the amp I wrap it around the back side of the amp with some slack left, so if I pull on it, it has some amount of give before it yanks the plug out.

Yea I planned to do that with some silicone holder stuck to my desk.

Finally tested it (yes, we have time, nowadays...): When pulling out the headphone plug, it's unavoidable that you short - at least for an instance - right and left channel. But there was no short to ground which I originally thought we'd have - and that would be the ('dangerous') problem described above. (Yes, we should test your hypothesis before reproducing them.)

Thanks for that, so I'd still rather just mute my amp/turn it off before I unplug it then just to be safe. Rather be redundant than waste a bunch of money on dead cans.

And, btw, I'd stay with your amp, be happy that you've got a 'Lake people', they have a good name here.

I'd like to stay, but I would also like an amp with atleast gain settings. The G109-A do have gain settings but it's internal, and I don't like to keep opening it. I've read the SMSL SP200 has DC protection as well as the THX 789. I'll wait for a while I guess until the THX AAA gets out, 'cause I don't mind to keep using SE over Balanced.

 

[solderdude]

Thanks for that, so I'd still rather just mute my amp/turn it off before I unplug it then just to be safe. Rather be redundant than waste a bunch of money on dead cans.

I have (hot) unplugged many headphones over many, many years and never once blew up any amp nor any headphone.
There is no 'mechanism' for a headphone to blow anyway while pulling the plug while playing anyway.
I did have some broken wires and dodgy contacts over the years.
Especially the common contact often gives more problems for some reason than the tip or ring.

It is always good practice to switch things off or stop playing music and then pull the headphone cable anyway. Blowing up headphones is not going to happen while pulling a TRS connector.

 

[hellboundlex]

This is why I use XLR. Even unbalanced, i get an adapter.

 

[JohnYang1997]

Unplugging TRS doesn't short the headphones but the amp. It's impossible to get channel imbalance just from this.
Yanking the plug physically is a different story but not much. The issue with focal is that the wire in voice coil is so thin that it can break relatively easily (still a very small chance). It's not the electrical disconnection causing this but the physical movement, the shock that does it.