I picked up my CTH from the UPS store this morning ... I've been listening for 3-4 hours off and on .... During the last hour or so I'm starting to get a metalic whine or ting in the left channel ... Volume pot has been at listening levels with minor adjustments depending on song loudness level ...
Is this something to do with burn in or the tube
It may be related to tube burn-in. Give it some more time and see if the issue goes away.