Do I need an headphone amp?


I have a B&K Ref 30 driven by a Cinepro 2K63. I am considering the purchase of Grado or Sennheiser headphones. Will I need an external headphone amp?

Thanks in advance.
dwwhitley
Agree with Yidimsum. He is corrrect. (See my Portable System here on Audiogon).
Grados are efficient and can generally be driven straight out of a headphone jack of a receiver pretty nicely (32 ohms). The Sennheiser 580/600s are really inefficient at 300 ohms and a headamp helps a lot.
Does either piece of equipment have a headphone jack? If yes, then I would suggest trying whichever headphones you like with the headphone jack first. If no, then you will need to feed a headphone amp from the tape monitor circuit.
I would suggest picking the headphones first as some headphones require an amp to sound their best while others will sound fine from a headphone jack. Also, not every headphone jack is a piece of junk as headphone amp manufacturers would lead you to believe. Headphones are a very personal choice, as not only sound quality, but comfort matters. If you do decide you need a headphone amp, I would suggest searching the forums at headwize.com and head-fi.org for more info.