Putting a headphone jack on a guitar amp?

[Monkeyleg]

There's a 100 watt guitar amp that I might be able to get a decent price. A big problem is that it doesn't come with a headphone jack, and I don't think my wife would appreciate loud music late at night when she's trying to sleep.

The amp has a jack for an external speaker. Is there any way to modify this--preferably externally--so headphones can be used?

Thanks for any replies.

[Nick1911]

What's to prevent you from plugging headphones into that jack, straight up?  Impedance mismatch?

[CNYCacher]

Maybe?

[Tuco]

Headphone has an extra conductor - stereo jack.
Guitar is a mono jack.

They will fit, sound may come out, but there may be channelization issues.

http://en.wikipedia.org/wiki/TRS_connector

[roo_ster]

What's to prevent you from plugging headphones into that jack, straight up?  Impedance mismatch?

The speaker has output pot from 0-11, the headphones do not.

[Tuco]

Try it -  worse case you'll need a 1/4" mono to 1/4" stereo adaptor (radio shack) or a soldering iron to bridge the  signal in the cans.

[Jim147]

But will the speaker out jack mute the internal speakers?

jim

[Monkeyleg]

Thanks for the replies. I thought there was some circuitry to reduce the volume to the headphones because an amplifier at low volume doesn't have the same sound as at mid volume. Or something like that.

I don't think the speaker output jack will mute the internals, either.

[Fitz]

do NOT plug headphones into an external speaker jack.

SPeaker cabinets receive a lot more power than headphones do. At best, you could ruin your headphones, or your amp. At worst, you could ruin your ears. That's why speaker cables for guitar amps are different than guitar cables.

If the amp has a "line out" you can get a box that will allow you to use that.

You are also correct in assuming that the using anything but a headphone jack will not mute the internal speaker.


Another option is a seperate specific headphone amp... Like this:

http://www.voxamps.com/amplug/

Or, if you have an iphone, you can get the line6 dongle for it.

[geronimotwo]

i don't think you will get the same tone as a speaker under power, and you may need to be careful about blowing your headphones (or your amp if you disconnect the speaker).  large speakers can absorb a lot more power, picture running your home stereo speakers off your ipod, it doesn't work.  they do make practice devices ( the rockman was a big hit as you could use headphones, or run through it, for that 80's rock sound), not sure if they have one with the sound you want.

[Balog]

If it's a headphone out that has 1/4" instead of 1/8" get an adapter. If it's a power tap to run another cab then it has too much power and will destroy your headphones. Think putting a alcohol fueled funny car engine into a Kia... even if everything lined up the power would destroy the drivetrain/transmission.

[CNYCacher]

Typical headphones impedance is hundreds of ohms. Speaker cabinets are commonly 16, 8 or 4 ohms.

Amplifiers use voltage to offer power to speakers.  Speakers draw the power which is offered.  Headphones don't draw a lot of power.

Think plugging a teeny-tiny cell phone charger into the same outlet that normally powers a table saw.

The preceding example is offered as counterargument to the car analogy.  Neither are completely accurate.  The truth is somewhere in the middle.  The middle of the volume dial, most likely.  My and Ohm have been tight for a while.  Give the $2.49 radio shack solution a shot.

[Balog]

I thought most lower end headphones were lower resistance, like 40 or 50 ohms? And speakers respond to the amount of power fed to them. They try to reproduce the signal level sent. Which is why it's possible to blow one's speakers when attempting to send too much signal to them.

[Fitz]

Typical headphones impedance is hundreds of ohms. Speaker cabinets are commonly 16, 8 or 4 ohms.

Amplifiers use voltage to offer power to speakers.  Speakers draw the power which is offered.  Headphones don't draw a lot of power.

Think plugging a teeny-tiny cell phone charger into the same outlet that normally powers a table saw.

The preceding example is offered as counterargument to the car analogy.  Neither are completely accurate.  The truth is somewhere in the middle.  The middle of the volume dial, most likely.  My and Ohm have been tight for a while.  Give the $2.49 radio shack solution a shot.

I have ruined an amp by plugging in speakers and not setting my impedance selector appropriately on the head.

I suspect that if there's THAT much difference in impedance between the headphones and a speaker, he could potentially ruin the amp.



OP, the real answer here is this: either get a seperate headphone amp like what i linked above, or get an amp with a headphone jack.

[Balog]

I think that generally amps are damaged by too low an impedance load, as it flows too much current.

[280plus]

No idea on the electronics but I suggest you get one of those little cheap mini practice amps that only use headphones. Not sure of brand anymore.

[Fitz]

http://www.voxamps.com/amplug/
http://www.voxamps.com/amplug/
http://www.voxamps.com/amplug/
http://www.voxamps.com/amplug/
http://www.voxamps.com/amplug/