Can I hook up a headphone amp to my integrated?


I am interested in getting some nice headphones.  I currently have a Line Magnetic 518i integrated amp.  As far as I know it has 3 line in inputs which now has my cd player in one, my phono preamp in one, with one remaining.  It also has 1 preamp line out.  The amp has no headphone input?  I mostly listen to vinyl (90%), and sometimes cds as well.  I would like to get a nice headphone amp and hook it up to the LM so I can listen while playing records and cds.  Can I do this, and how would I hook it up?  Can I just hook it up to the remaining line in input?  I would appreciate any help I can get on this....I'm a bit confused if this will work, and if not, how can I go about getting a headphone amp working so I can begin to listen to headphones again?  Thank you all!
ekimg
Getting a good headphone amp is a very good idea.  If you have a tape out connect that to the headphone amp.  That's exactly as I have done with my system.
I don't have a tape out connect.  I only have the three line in and one pre-in?
It also has 1 preamp line out....

I only have the three line in and one pre-in?
It appears that the second statement is correct, but not the first, and the only outputs provided by the amp are its speaker-level outputs.

Therefore the possible approaches are:

1)Connect the amp outputs to some sort of a speaker-level switchbox that would route them to either the speakers or to some sort of a speaker-level to line-level converter that would in turn connect to the headphone amp. Not sure how practical this approach would be, or how good the results would be.

2)Same as approach 1, except without the speaker-level to line-level converter but with a headphone amp that can accept speaker-level inputs. Not sure if such a thing exists, and at best this approach would severely limit your choice of headphone amps.

3)Choose a headphone amp that provides only a single line-level input. Obtain a line-level switchbox that would select between your phono stage and your CD player, and connect the output of the switchbox to a line-in of the integrated amp and also to the input of the headphone amp. Given the fairly high input impedance of the integrated amp (measured by Stereophile as 59K or more for the LM-518IA, at various frequencies), a headphone amp having an input impedance of 47K or more would be preferable in this case, especially if your phono stage or CD player has an output impedance of more than a few hundred ohms.

Line-level switchboxes that would be suitable include the DB Systems DBP-2JAU/5 ($110), with which you would need a pair of y-adapters or splitters to connect its output to the two destinations, and the Decware ZSB ($359), which provides two sets of outputs.

This approach should work reasonably well, as long as the two source components do not have unusually high output impedances and as long as cable lengths are not unusually long.

4)Choose a headphone amp that can accept two sets of inputs, and use splitters or y-adapters to connect the phono stage and the CD player to both the headphone amp and the integrated amp. A headphone amp having an input impedance of 47K or more would be preferable in this case, especially if your phono stage or CD player has an output impedance of more than a few hundred ohms.

This approach should also work reasonably well, as long as the two source components do not have unusually high output impedances and as long as cable lengths are not unusually long.

Good luck. Regards,
-- Al

Thanks Al.  Yes, the second statement is correct:  3 line level inputs and 1 pre-input.  I have a Manley Chinook phono preamp, and a Marantz 6005 CD player.  My cables are not unusually long. 

Seems like #3 or #4 above make more sense at least to me.  Do you have a suggestion for a headphone amp or amps that would be a good choice given the LM, Marantz, and Manley?  FWIW I'm using a VPI Prime into the Chinook.

Or, to show my ignorance on these matters, can I get a pre-amp that has a phono out and plug that into my LM's pre-in?  I think I saw something like that on the HeadAmp website?