Any 1/4in jack that will not short out?

[Voodoochile]

If you just retract the plug from the jack normally, there is no problem. If you were to stop partway in or out (shorting) then that would be different. I actually prefer not to use the locking jacks for the reason that if anything, removing a plug from one of those takes a bit longer than from a normal jack.

Don't forget that it also has to be isolated from the chassis, so stock selection is limited. You can isolate a regular jack as well if needed.

Someone around here disassembled the locking Neutrik and modded the tension spring for the latch (was ist los or doobooloo maybe?), which seems like a reasonable thing to do.

 

[rickcr42]

Quote:

I don't see why a company couldn't make one that didn't, though

any time you complicate the simple you add a potential for part breakdown and failure.It is the simplistic nature of the phone plug and the high reliability that makes it the choice for most pro gear .

There are "switching" phone jacks that you can wire to do anything you want but remember they are called switching for a reason-there is a "switch' inside and not the best quality either.that is why you rarely see them on high end gear where reliability is important or the company would be ripped in public forums for putting out garbage.
If I were to design such a device it would have a "cam" action that would require a lever to open and close the cam from coming into contact with the plug.This would be neither cheap and maybe would prove unreliable over time.Any mechanical moving part will wear out at some point but before it does it will become intermittant and unreliable.How soon depends on how many times it is "cycled".

The simple fix is always the best and every single amp i build for personal use has a 'mute" switch inline with the output.By using a high quality switch here it does nothing bad to the signal but removes the annoying "pop" on power up and pulling or inserting the plug into the jack.But the reality is no harm will come to your headphones unless the volume is so high you are listening at dangerous levels anyway and then i would worry more about my hearing than i would any amplifier.

 

[Pars]

Quote:

The simple fix is always the best and every single amp i build for personal use has a 'mute" switch inline with the output.By using a high quality switch here it does nothing bad to the signal but removes the annoying "pop" on power up and pulling or inserting the plug into the jack.

Rick,

Do you put this in series with the output so it just opens the oputput connection, or does the switch short the output to ground? I know the Mute on my tube pre just shorts output to ground, but I don't know how kindly silicon would be to this. The amp I am building now may be used as a preamp also, and since I leave the power amp on all the time, turn-on/off thumps or whatever cannot be tolerated. I was debating what the best way to handle this would be.

Chris

 

[morsel]

Tophu: The PPA (up to v1.1) has 4 HA5002 buffers per channel. The total output current capability of about 1A exceeds the maximum output of the power supply, which at less than .5A is the limiting factor. This has been discussed many times already.

 

[BradJudy]

Quote:

Originally Posted by Glassman XLR has three pins, how many signals do you want for your headphones? aren't left, right and ground enough? the best would be to use that nice XLR/TRS panel mount Neutrik connector used by Headroom or Meier, that way one can choose between using XLR adapter or the jack itself..

I like that idea.

 

[rickcr42]

Quote:

Rick, Do you put this in series with the output so it just opens the oputput connection, or does the switch short the output to ground? I know the Mute on my tube pre just shorts output to ground, but I don't know how kindly silicon would be to this. The amp I am building now may be used as a preamp also, and since I leave the power amp on all the time, turn-on/off thumps or whatever cannot be tolerated. I was debating what the best way to handle this would be.

sorry about the late reply chris.Too many parties this time of year and i am not one to miss any

Yes,a simply switch that opens the circuit for most amps.This prevents two things :

1-the thump through cans when powering up or shutting down if the headphone is always plugged in

2-The possibility of shorting out and damaging an unprotected and delicate output stage.

the second you can protect against by adding current limiting/output protection resistors inline with the output but there are tradeoffs and the protection also limits current delivery to the load so it is not for everyone.
Tube amps unless OTL have the advantage of a transformer on the output betweeen the tubes and the jack so shorting through a load resistor may be the best solution.Another option for some amps is shorting the input to ground or turning the volume control to full mute which is the same thing really.Most will not pop or click,some will.
It is very amp dependant though fully balanced designs seem to be the most well behaved with no mute at all.Common mode noises cancle each other out.

 

[Pars]

Thanks for the reply Rick, yeah I know the parties this time of year (not this year, but been there <g>.

My amp is SS and as far as I know direct-coupled. Tube pre has interstage coupling caps but no transformers.

What I might try (when I get around to it) is putting in a switch that a) opens the output and b) shorts the output after the switch to ground (i.e., does not short the output stage of the headamp/maybe preamp to ground, but instead shorts the output jacks to ground while opening up the output... effectively shorting the input to the power amp to ground. Any thoughts?

Thanks,

Chris

 

[rickcr42]

If i am following ,what you are saying is a mute to ground on the preamp and an open circuit mute on the headphone amp ?

First,I built a dedicated 30 second turn on delay muting relay for my preamp because it can flat out wipe out my tweeters out on turn on (happened already once ,sensitive speakers and high power don't play well together).Since this is at the output of the preamp and goes to my "monitor select" switch (amp A,amp B,headphone amp a headphone amp B) it at the same time shorts ALL amp stage inputs to ground at the same time.
But none oif my present headphone amps and no power amp i know of likes the output going to a dead short to ground so i have the DPDT open circuit muste switches inline with the headphone jacks and always hit "mute" just before i turn off the headphone amp.then when i turn it back on it is a conscious effort,something i must do to actually activate the cans again so I am reminded to wait until the delay relay LED stops blinking to signify that is stable and so should the headphone amp be.

there is a circuit at Walt Jungs web page (check links section) that while meant for use as a speaker saver could most likely be modified for headphone amp use.Check it out.

Rick

 

[rickcr42]

just wrote i know of no amp that likes to be shorted to ground and here is one from the Pass DIY site-the "zenlite" article that does just that :

http://www.passdiy.com/images/projects/z1-fig14.gif

i guess i am just a coward man

 

[rickcr42]

The Jung "speaker saver"

http://home.comcast.net/~walt-jung/w...aker_Saver.pdf

 

[Pars]

Thanks Rick, I'll have to check those out.

The headphone amp I am currently building is a Gilmore Dynamic. Dr. Gilmore has indicated that it can tolerate having the output shorted, but like you are doing, I wanted to build some type of delay circuit using a relay perhaps that either shorts or opens the output upon turnoff (muting) and likewise waits to connect the output until things have stabilized. DC offset monitoring would also be a good thing, and I saw a circuit around here somewhere that looked like it would work well for this.

This is mainly for normal use, although I may try this as a preamp instead of my Counterpoint tube pre, hence the absolute need for some type of muting.

Chris