Old post I know. I own a 7T that was restored, and it sounds okay. Recently purchased and original 7T in pristine condition. Every component is original. The sound stage is so deep, wide, and transparent that it has made me rethink ever restoring another component unless it’s out of spec and in obvious need.
My tech has confirmed that the original untouched 7T unit exceeds its original specs-all across the board. It is super quiet and at the moment the finest sounding preamp I’ve ever owned.
Comparing it to my model 7 tube preamp, the 7T is a bit quieter, and the bass much tighter. Mids are very similar and the highs are a bit softer/smoother on the 7 tube model. You would be hard pressed to tell them apart, as their voicing is so similar. Just saying, really, really give pause to having something restored because it’s old. I know I will.