"Modify" Stax headphone Transformer SR-7 Pro??

I have a pair of Stax Lambda Headphones with StaxSR-7 Pro Box which I bought used. They get moderate use and are better than any non-electrostatic phone I have owned.Though, the sound can be a bit hard and biting, it is detailed and bass is deep. In order to avoid connecting the Stax transformer to my amp, I bought a Macintosh 1700 receiver(also,I use its tube tuner front end) and drive the headphones from the receiver speaker leads; I also have run a tape-out lead from my CJ pre-amp to listen to other main system modes. I realize that the Mac 1700 pre-amp stage may be crappy and creating some of the "hard" sound. I recently switched interconnects from my main system pre-amp to the Mac. I am now using an Audioquest Coral. It is better than the cheap Straight Wire I bought 10 years ago. So... should, I get ride of the MacIntosh and look for a newish and cleaner integrated amp?? (I don't want to get crazy with this and spend many dollars investing in an esoteric tube amp.)Or, can the Stax box be modified for cleaner sound at a reasonable price?? I enjoy the sound of the Stax system but I don't want to turn this into an extended science project which it has become. (I am sure this set-up probably sounds ridiculous to some tekkies) Though, I am told the Stax system I have, though over 10 years old, is generally superior to the new Stax models 2020, and possibly 3030 which is over $1200. Help!!! All suggestions and advice greatly appreciated. Thanks, Jimbo
Why don't you just make a pair of quick-connects to allow you to easily hook the Stax box to your amp? The better you put into them, the better you'll get out. Cheap, too.