I purchased the OPA1692 from ebay at this link: https://www.ebay.com/itm/OPA1692-Low-Power-Low-Noise-High-Performance-Dual-Bipolar-Input-Audio-Op-Amp/232933573263?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649. I'm not sure if I received an authentic opamp. It has TI 73 P692 on it...

60 bucks.  http://www.newegg.com/Product/Product.aspx?Item=N82E16826532001 MartinLogan Mikros 90 Refrence On-Ear Headphones, Black

   

Hello everybody, long time lurker first time poster.   I primarily listen to classical music, and from what I have read and researched the HD 598 seem to fit the bill pretty well, but I'm looking for a headphone that won't leak sound, as I will be using them in my dormitory and other quiet...