I have a new Subsequent 37 CV and just noticed there is no sound from the headphone jack. Both Headphone Volume and Master Volume knob setting make no difference, however, if either are set to maximum then you can hear a very faint, distorted tone in the earphones. I am new to this piece of gear and would like to know if there is another parameter within the synth affecting the headphone output that I may not be familiar with. I’m really hoping this is the case and not a problem with my new board! Anyone?
It should “just work”, there are no hidden parameters. The headphone level is dependent on the main volume though, so it must be turned up for the headphone level to have any effect.
Thanks Dr. Justice. Have a replacement on the way now from Sweetwater 
The replacement arrived today, apparently it WAS a problem with the headphone jack. The new one works fine. For a little while I had TWO 37 CVs on my keyboard stand! Cool enough to take a picture. Appreciate the fast replacement from Sweetwater.
Wade, was the unit with the headphone amp issue #1956? I ask because I ordered one from Sweetwater and just had to do a return for the same issue on that serial number.