[TenTec] Speaking of Headphones (Orion)

[Stuart Rohre]

Lee, you should be fine using the 600 ohm phones.

With any speaker or phones, you do not have to EXACTLY match impedance the 
way you do with antennas and rigs.  Phones don't use much power, and are 
used over a wider range of impedance sources than speakers.

You should start from a low volume setting as higher impedance phones 
require less current to drive them to full output.  The volume control and 
your ears should tell you when there is too much drive well before you 
damage anything save your own hearing.

Now on some old military gear, you don't want to put on 8 ohms phones on a 
600 ohm audio output, for it will load down and you might not have the power 
source to drive the less sensitive 8 ohm phones.

Stuart
K5KVH