I own a Lafayette tube amp form way back when. I have not found anything really out there that can compete with this beast. Probably because of the transformers used back in the day. I have heard very nice hybrid class D amps that sound pretty good also. It all depends on the old amp and the new amp. I would like to have my Krell 50 amp back also. Hearing differences also to me depends on the source. I personally would rather upgrade my source then my amp. To me that brings a higher reward in sonic improvement.
Happy Listening.
Happy Listening.