Certain frequencies hurt

Recently, due to certain frequencies coming across excessively loud and hurting my ears I've decided to run headphones (Sennheiser HD 800 or Hifiman HE 6se) instead of speakers through my power amps speaker taps. Then I ran across this yesterday:

"I’ll point out you need to be careful with Tube based speaker amps, they are designed to drive a specific impedance, and you’d want to match that with either a resistor in parallel with the headphones or a transformer to impedance match.
It’s also the case that more powerful tube speaker amps will self destruct/blow a fuse if a load is not connected to the terminals, because without the reflected impedance the circuit will draw too much current."

So will running headphones through my Audio Research Ref 75 possibly cause harm to the amp or preamp (both tubes)? The sound is sublime and it causes me no pain. Is this (speaker) set-up overkill for these headphones?