[earl grey]

Really appreciate your continued support and suggestions for things to try.  If any of these are half as good as the first one it will be a real win!
 
I noticed the DAC.  I am confused about how that works.  You feed in an analog signal via the 6.5 mm plug from the imac to the DAC right?  Then it converts to digital and back to analog and to the amp?  I must be missing something here.  My apologies for such a newb question....

 

[PurpleAngel]

  Really appreciate your continued support and suggestions for things to try.  If any of these are half as good as the first one it will be a real win!
 
I noticed the DAC.  I am confused about how that works.  You feed in an analog signal via the 6.5 mm plug from the imac to the DAC right?  Then it converts to digital and back to analog and to the amp?  I must be missing something here.  My apologies for such a newb question....

 
You connect the source (iMac) to the DAC (Sabre U2) using a USB cable (digital connection).
Then connect the Sabre U2's 3.5mm analog output jack to the analog input on the amplifier (RCA or 3.5mm).

 

[earl grey]

Thanks.  That's makes much more sense.  I didn't even know that you can use a usb out from the mac.  I have some learning to do.