Is there such a device or devices that would allow you to use an existing amplifier that has no headphone jack to play headphones?.
I have a 50w integrated (tube pre amp section & ss power amp section) that would (I imagine?) need a severely attenuated output (from the speaker outlets I'm guessing?) housed in a box of tricks with a headphone jack?
The reason Is I want to retain the existing source/dac/amplification rather than a seperate headphone amp.
Headphones would be Sennheiser/AKG low impedence type with 1/4" jack.
 
T.I.A

Speaker taps can be used--but be very careful and use only headphones that can handle a great deal of power.
 
If you don't know what you're doing, it is probably a bad idea if you care about your cans.

I do not want to upgrade the amp, it has the perfect sound as far as I am concerned. I do not have upgraditus, I want to retain the sound I already have, as much as possible, but I do not want to fry the headphones.Hard to believe this way of doing things seems to be almost completely ignored or is it the love/need for yet more equipment?.

Would something like this be what you're looking for?:
 
http://www.vinylflat.com/canopener.html

Wow!!!
Exactly what I was looking for. Much appreciated sir.

I would want to make sure that magic box isn't just a bunch of resistors that bring the speaker-level voltage down to headphone-level.

I think trying to use the speaker amp for headphones is using the wrong tool for the job.

You really don't know how your amp will sound with headphones. You know that you like how it sounds with your speakers, but that doesn't mean you will like how it sounds with your headphones.

Art has their headTap, which is a speaker to headphone junction.  I am not sure whether or not the speakers have to be connected.
http://www.amazon.com/ART-operationConnects-amplifierVolume-regulates-headphone/dp/B0002E585Q
 
Heres a www page with a DIY solution...
http://robrobinette.com/RobinetteBox.htm

billybob_jcv said:

I would want to make sure that magic box isn't just a bunch of resistors that bring the speaker-level voltage down to headphone-level.

I think trying to use the speaker amp for headphones is using the wrong tool for the job.

You really don't know how your amp will sound with headphones. You know that you like how it sounds with your speakers, but that doesn't mean you will like how it sounds with your headphones.

Click to expand...

I have been in touch with the manufacturer & yes there are resistors in there for that purpose. That is what I wanted, is there a problem with that?. I am told resistors will tend to
make the head phones sound slightly warmer/bassier which suits me with the cans I have (AKG241). However if the same "quality" of sound is still there than that would be fine
& a good/simpler alternative to a seperate headamp. Heretical here at Head-Fi maybe, but as far as I can see the only way to find that out would be buy it, & for $80 it's worth it,
especially as I am really curious to know.

I think the biggest aspect here is the common ground at the TRS connector, assuming the OP is using a single ended headphone.  Not all speaker amps can handle having their negative outputs common grounded.  I do not know if a simple resistive circuit device effectively isolates the negative terminals.
 
I would be very wary of this scenario.
 
[EDIT]
That can opener device is nothing more than $6-7 ceramic power soak resistors.  Not sure how they are connected, or what the resulting resistive load is.  But resistors in-line to the headphone definitely can color the sound.  Kevin Gilmore had a really good write-up on resistive "impedance" adapters.  Been a while since I read it, but IIRC the general idea is the resistive value needs to be at least 3x that of the headphone impedance if you do not want to significantly color the sound.  This matches what I have found in my own experimentation.
 
http://www.avsforum.com/forum/dbtreview.php?do=view_review&id=4297
 

Yikes... that things $80!!!???  For that kind of dough, you may as well do it right and get a dedicated headphone amp.  Use one of your receiver line outputs, and feed that into something like a Schiit Magni or Vali.

kramer5150 said:

  Yikes... that things $80!!!???  For that kind of dough, you may as well do it right and get a dedicated headphone amp.  Use one of your receiver line outputs, and feed that into something like a Schiit Magni or Vali.

Click to expand...

 

Hey DavidK... your citypulse amp also has preamp line outputs.  IMHO it would be better to use those and send an analog line out to a dedicated headphone amp.  I do this every once in a while, with my darkvoice 337.  I send its line output to my PPA, to give it a little tube preamp "color".  Not unpleasant sounding at all.

Well I can see your all trying to persaude me otherwise LOL, but regardless my intention has always been to maintain the sound of
TDA 1541 DAC through preamp with 6F8G 1940's tubes, (amp modified to accomodate) superior to 6SN7 tubes which are superior to any 1950's miniature tube you care to name through the excellent SS power stage. Next month will purchase what I consider the excellent value (for a mostly non solderer) $80 Can Opener & will report back.
Having read the reviews which are positive, convinced me to try it, & it's US to boot. It's been a long road to get to this point & the above paragraph represents 7 years of trial & error, because in the final analysis no matter what anyone says, it's your own ears that
determines what is good & what is not. Ironically I have found with prudent purchases with extended listening tests has resulted in the most rewarding sound for the smallest outlay. For me less $$ has resulted in better sound, turning the established wisdom on it's head, providing one can ignore the hype & also do objective testing which IMO can only be done over extensive time & repeatedly.

Got for it!!  Nothing wrong with giving something a try.
 
Taking one for the team and good luck!!