Man am I confused. The first bit of confusion is the notion that it is the transformer , which continues to provide power making low level music via residual power from the transformer after the amp is turned off. I am not an EE or even an ee or e, but I thought that power came from the electrolytic capacitors.
After reading the strongly worded cautionary statement regarding about not leaving headphones attached,. However my personal history seems to contradict this thinking . I have never experienced nasties between HP and the plate of the power tube in an OTL design.
What kind of damage occurs? I have should have been destroying my headphones for years, yet they sound pretty good to me barring normal wear. My current HP system construct is a SinglePower Extreme (an OTL) and either Sennheiser HD 700s the AKG KXX. There is the occasional fairly rare guest appearance by the Beyer DT 770 Pro 32 Ohm.
Oddly I have never heard or read of HP immolations or pyrotechnics. Yet I know I will of course unplug my HPs. I have as bad a case of audiophilitis nervosa as the next guy!
Seriously is there an idiots guide to a basic understanding home electronics for home and perhaps (only if absolutely neccesarry} pro audio..