How do I get my wireless headphones to work with my iMac

Wireless head phones works on principle of wireless technology.
The phone has a reciver and tv or Audio system has a transmitter ,.
WiFi/blue tooth are examples.

I have looked at an image of NAD rear and it has RCA type jacks. I would plug it into the AUX sockets. Now to if it will work. Plug some stereo headphones into the iMac socket. If you can hear sound then the cable you intend to buy will transfer the sound you hear to the amp. If you want to record from the amp to your computer you will need another a different input on your computer and that would need to be connected to tape 1/2 out.
Any 3.5mm socket to RCA will do, they are not expensive plenty of cheap ones on Amazon and E-Bay (image shown). You will need two if you do want to record as well.

Try eBay, lots of iMac spares, you might be lucky.

Maybe your wireless headphones has broken. You can new one from Mubuy.com. There all kind of wireless headphones in this websites.

• Goodmorning, I received Slick HP921 Wireless Headphones yesterday I have perfectly utilized them yesterday but today I have no communication between the wireless transmitter and the wireless headphones without changing anything since yesterday.
  The wireless transmitter is turned on but it's not trasmitting. The headphones work perfectly with fm mode and also when i connected the single green plug with other devices ( pc, phone ).
  The problem should be in the wireless transmitter.
  What I have to do ?
  

I took the advice of one of your correspondents by connecting my Sony ICD-SX365 recorder to my iMac with a simple audio cable by inserting the output jack in the recorder's slot for headphones and the input jack in the iMac's slot for microphones. I used the freeware program Audacity to import the track onto the computer and Switch to convert the file to mp3.

For connecting your mac computer you may need to configure router . What you can do you call call linksys Free Technical support - Direct number is 1800-326-7114

On the iMac choose Create Network... from the Airport menu. Then the Gateway laptop will be able to join the iMac's created network.
macs2u

from what I've read, the imac has a 3.5mm (.138) jack while the Bose jack is 1/8 (.125). very small difference in size (.013), but enough to cause problems.

I have the same problem with my dlink router MacBook Pro... I've tried everything to set up a secure wireless network and nothing works.