Can Levinson 512 be directly connected to a headphone ?

I can’t say at this point what the problem may be, of course. But here are some thoughts:

1)First, are you sure that the adapter is intended for two-channel applications, and therefore keeps the two channels separate from each other and from the ground connection? For example, an adapter such as this one would result in a short circuit between the two channels, and should not be used.

2)If the headphones have particularly low impedance, in the area of say 8 to 24 ohms, it would be more likely that they are responsible for the problem than if they have considerably higher impedance.

3)Assuming you have confidence in the suitability of the adapter, the way to tell whether the use of the headphones is responsible for the problem would of course be to use the player a few times with and without the headphones connected.

Good luck. Regards,
-- Al

Hi Al
Your answer and instruction are great, very very helpful !
More and more l intend to have a  project that I should use a formal highend headphone amp to get rid of those electronic things that must be taken into consideration.
By the way, in your first reply, you mentioned "   You would also have to provide a means of adapting the headphone’s plug to the player’s two RCA outputs, of course." If not that kind of simple cable shown by the link you gave above, what pattern of adapting apparatus (  some kind of adapter ? special cable ? or even an adapting box......) can be used?
Could you also suggest a link to know?

Thank you again !

Assuming the headphones have a standard 1/4 inch plug the adapter shown at the following link would be suitable, as it is designed for two-channel applications:

https://www.bhphotovideo.com/c/product/222622-REG/Hosa_Technology_YPR_257_Stereo_1_4_Female_to.html

Good luck.  Regards,
-- Al
 

Thank you so much !
Happy weekend !