Sennheiser - Over-the-Ear Stereo Headphones - Black

Hello, In most cases you would not need an amplifier for common use with headphones. The amplifier is better when used with headphones that require more power, or need a higher impedance to more efficiently send the audio signal. Our high end audiophile headphones like the HD600, HD650, HD700, and HD800 would require an amp to perform best, but any other headphone would not require an amp. That being said, an amp can always add improvement, such as volume, and EQ changes if so equipped. Most users don't like to have an amp separate for portable devices as it will add more weight, and is another device you have to carry around, so it is most popular in stationery use, like at home. I hope this helps, let me know if you have any other questions. Thanks

Hello- Your Toshiba computer does not have enough output to drive these headphones properly. Yes, when plugged in, they will sound pretty good, however, with a more powerful headphone circuit they will sound amazing. You should consider plugging these into a stereo receiver or headphone amp that can provide enough power to properly drive a 300 ohm headphone.

Get the 600's and don't look back. Although the 550's are probably a good set of cans, the 600's are legendary and are used as the reference point for all other headphones to be measured by.

Yes, definitely need an amp.