The manual for my new B100 Integrated Amp says that "only headphones with impedances of greater than 50 ohms should be used."
What will happen if I use a pair of phones @ 32 ohms? Will it just affect the sound? Could there be damage to the headphones or amp?
Just wondering.... 
Hi Moon Doggy
I was into headphones in a big way when my son was younger, I still keep them on hand and went trough trial and error trying to get the best performance out of them. The Bryston headphone output will drive most headphones satisfactorily but it’s running off the preamp output, no nothing will happen to the phones or the Bryston.
My biggest problem with the Brystons was that to drive most of my phones, AKG 501s, AKG701s, Sennheiser HD580/600s the volume needs to turned up fairly high, 2-3 o’clock (ok I like to listen loud) and is actual too low when listening to vinyl. Not only that but on occasion the phones were disconnected while the things were turned up sending the full output to the amp/speakers.
Also, my Grado SR325is at 32ohms, will run on a pea sized amp and have more than enough volume with the Bryston but they like current to sound their best which is why 50 ohms and above is mentioned.
So to answer your questions, you should have no problems whatever running 32 ohm headphones, they’ll just be current hungry, just try them and see if it’s adequate.
Which phones are you planning on using?
Robert