250 ohm impedance.One-inch diameter oxygen-free copper voice coil heightens signal transmission and conduction for precise, accurate sound reproduction. Computer-optimized ferrite magnet structures provide deep bass and treble clarity. Closed cushions form tight seal around ear eliminating ambient sound and maximizing bass response. Ear cups fold flat for convenient travel and storage. Adaptable steel and rubber headband further ensures isolation. Equipped with a coiled, single-entry 8 foot cord with 3.5 mm plug and 6.3 mm adapter, and a sleek case for protective portability. These were purchased through Amazon.com two years ago for a project to test driving headphones capacitor coupled off the cathode of a 12AU7 or 12BH7 and required high impedance headphones. Have used them on 8 ohm outputs without any noticeable difference. These have a nice high end response but are not piercing so if you like lots of highs you might be disappointed. The midrange on these is very smooth, more so than most headphones I've used and makes listening very enjoyable to me. I would keep them but I am looking towards a move overseas and need to cut way back on my possessions. These have hardly been used perhaps at most 100 hours. The headphones, case and original box are in like new condition.
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