Can Levinson 512 be directly connected to a headphone ?

The 512’s specified output impedance of 10 ohms seems low enough to provide results with most headphones that are at least fairly reasonable. You would have to use its variable output capability, of course, to control the volume, and to keep the volume within reasonable limits. You would also have to provide a means of adapting the headphone’s plug to the player’s two RCA outputs, of course.

The issue you are likely to run into, though, is that with most headphones you’ll probably have to set the volume control very low within its range, where depending on how the player’s volume control mechanism is implemented the resulting sonic quality stands a good chance of being compromised to some degree. That issue can probably be minimized if the headphones have relatively high impedance (e.g., hundreds of ohms rather than tens of ohms), and relatively low sensitivity (e.g., 95 db/mW or less rather than 100 db/mW or more).

Regards,
-- Al

Thank you for so detailed explaining.
When directly connected from " Variable-Pattern"   two RCA outputs with
an  adapter cable for  two RCA to one headphone plug, after playing music for about 2 minutes, the 512 froze up and had to be powered off then on again to get it well.
Is it possible the problem was from a mismatching ? or, the 512 is bad and probably should be sent to be checked up/repaired?

Many thanks!

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 !