Can I hook up a headphone amp to my integrated?

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

Good! The Manley has very low output impedance, and while the output impedance of the 6005 doesn’t appear to be specified I would expect it to also be fairly low. The 6005 appears to have a built-in headphone amp, BTW, and provides a headphone jack, but of course that wouldn’t make it possible to listen to records via headphones, and its sonic quality is unknown.

Yes, approaches 3 and 4 certainly make the most sense among those I listed. The choice of headphone amp would probably be driven primarily by the type of headphones you choose, as well as by how much you want to spend. I have no particular suggestions to offer, assuming you are interested in conventional dynamic headphones, as in my case I use an older pair of Stax electrostatic headphones. Those require a special purpose amplifier suitable for driving electrostatics, which is also made by Stax in my case. And Stax or other electrostatic headphones tend to be quite expensive these days.

Yes, using the LM just as a power amp (connecting to its "pre-in"), with a separate preamp driving both the LM and the headphone amp (and preferably providing a "tape output" that would be used to drive the headphone amp) is certainly a viable approach. But of course it would be more expensive than approaches 3 and 4 (unless you can find a headphone amp that would provide such a preamp function itself), and it would result in sonics that may or may not be either better or worse than those approaches.

Good luck. Regards,
-- Al