Earphone Output

[blindsjc]

Hi friends,
Someone knows about earphones output schematics or any other information.
Get sound directly from the preamp doesn't show good quality.
Every schematic that I know do not show a earphone connection.

How the big ones like Fender and marshall do this outputs?

again, sorry about the bad English.

Thanks
Ronaldo

[darron]

some people use the ruby amp (9 volt tiny amp) as a headphone/earphone output, and you would eliminate the drive section.

basically you'd just send the signal to an opamp and EQ it a bit to suit the different type of speaker i guess?

here's a link to ruby schematic:http://www.geofex.com/Article_Folders/TStech/tsxtech.gif

[blindsjc]

Hi Darron,
Thanks for your reply. I found something very useful on
runoffgroove http://www.runoffgroove.com/phones.png

Some SSGuitar friends use the voltage divider to headphones
too, then I will try it. Add another specific amp for the headphones
appears to bring perfect sound but will make the project more
complex and expensive at this time.

Thanks a lot friend.

[d95err]

You need a speaker simulator to go with the headphone output, otherwise it will sound like crap. Guitar speakers roll off a lot of high- and low- end and you need to compensate for this to get a good sound with headphones. There are various speaker sim schematics around. Checkout the Runoffgroove Condor at www.runoffgroove.com.

[oldrocker]

Adding this headphone booster could help.  This circuit is true stereo or you could only use half.  If you're looking for a nice sounding headphone amp setup this is it.  If it's a guitar amp headphone setup then a Ruby would work.  Check out the circuit below.
http://www.minidisc.org/schem.gif

[blindsjc]

Friends,
I found a old marshall schematic using a headphone
output with some components like a cap and resistors
after the power amp section.

Somebody can help-me understand the real function
of these components? I think something like this would
be the solution for me.



Thx
Ronaldo

[blindsjc]

Image above sometimes doesn't work,
see the link: http://www.blindsjc.0catch.com/marshall_headphone.gif

Thx

[darron]

the link doesn't work either. but like i said, after you amp it up you'd have to EQ it a bit otherwise it will sound REALLY dull and flat, like your amp was under a heap of blankets. to EQ it to sound reasonable you would use some capacitors and resistors. capacitors leak certain frequencies about a Hz rate, relating to their value. so if you filter out some frequencies to ground (muting them) and set how much with the resistors it forms a simple passive equaliser. headphone jacks never really sound the same as the amp, and shouldn't be used for recording or anything like that obviously. they are pretty much just good for practice.

[d95err]

after you amp it up you'd have to EQ it a bit otherwise it will sound REALLY dull and flat, like your amp was under a heap of blankets.

I don't know if I misunderstand you, but I'd say it's the other way around. If you listen to an unprocessed line-out from an amp, it will sound extremely harsh with way too much treble because there is nothing to tame the high frequencies that normally are attenuated by the guitar speaker. You need to cut the bass a bit too and preferably, there should be a dip in the mid range.

[darron]

i could be wrong? try plugging your guitar into a distortion or boost pedal and turn the volume up and plug your headphones into the output.

[rockgardenlove]

Cool headphone amp...how loud does it go?

[blindsjc]

Hi friends,
I have tried a lot of options to plug my earphones,
sure the sound is a lot better with a cabinet simulation
like condor, but using a 10uF cap and attenuators like
marshall amps before the phones gives me decent
results. If the link doesn't work, try to cut and paste
to browser (just not accept hotlinks), try this schematic,
is very good and simple.

Thx

[Elektrojänis]

Cool headphone amp...how loud does it go?

Do you mean that LM386 based thing? Based on my own experiments with LM386 and headphones, I'd say it can get loud enough. Louder than most headphones can really handle, not to speak about ears. Most headphones can give ear shattering volume at 10mW. LM386 can give about 500mW (depending on the load though, but I'd say it can give enough for any headphones).

For example, AKG K240S (http://www.akg.com/products/powerslave,mynodeid,157,pid,252,id,252,_language,ENUS,_view,specs.html) has a maximum power handling of 200mW but it will produce 91dB with just 1mw. Every time when power doubles the volume goes up 3dB. Rock concerts in clubs are somewhere around 100dB (ta least where I live)... Sometimes more, Sometimes less, but I usually wear earplugs, because I dont want to damage my ears.

So... It should be loud enough. 

[David]

You need a speaker simulator to go with the headphone output, otherwise it will sound like crap. Guitar speakers roll off a lot of high- and low- end and you need to compensate for this to get a good sound with headphones. There are various speaker sim schematics around. Checkout the Runoffgroove Condor at www.runoffgroove.com.

No, you absolutely do not.  Go to www.headwize.org and look up the headphone amp article by Alan Campbell.  This has a build option specifically for guitar.  Unless one is a vintage amp bigot, it would sound just fine.

Be careful about words like "crap".  Remember, sound is subjective.

[rockgardenlove]

This may be veering off topic...but could feeding a 386 amp output into the line level input on my Presonus Firebox harm it?

Thanks!