I have Senn HD 600 which are amazing. I went with them over the 650 as most reports were that the two were basically par minus a smidge of bass. I thought about getting a headphone amp, but was quite pleased with the sound from the headphone output on my receiver (a marantz now, and formerly an older Sony ES). They even do ok, but with limited volume, through my iphone or computer.
One word of caution, do not buy from amazon as I tried that and ended up with a defective pair of headphones with a missing serial number. I bought mine from an authorized dealer and paid the extra $30 or $40 over amazon after returning the ones that were defective.
One word of caution, do not buy from amazon as I tried that and ended up with a defective pair of headphones with a missing serial number. I bought mine from an authorized dealer and paid the extra $30 or $40 over amazon after returning the ones that were defective.