Ooslik...I find it interesting that you mention the following: "...the impression I am getting is that the transients are a bit faster with less glare throughout the musical range." I have burned in for 200 hours both the line and phono stages of my Cortese. I am still getting what I hear as some glare or harshness in the upper midrange, especially with instruments like trumpets. I did not have this before purchasing the Cortese, which was the only component that changed in my system. Let's just say that my previous preamp, built by an extremely brilliant friend I had known, no longer became serviceable. It too was an extremely fine unit with fairly high gain. Anyhow, I've tried some tube rolling ( replacing Sovteks will Mullard, Amperex, Siemens, etc.) but still haven't scotched the problem. I have yet to try the likes of 6SN7s by Ken Rad, RCA or Tungsol. I otherwise like the Cortese very, very much. It is a superb component. But there is that somewhat "glaring" issue that you've experienced too. I'm wondering what needs to be done to neutralize it. I still do have other options beyond tubes that I've yet to try, but do you, or any others having faced the same issue, have any suggestions---or---have any of you found as solution for it ? Thanks very much.