Expert Glare Tamer Required And More Depth Please

Hello everyone.

I am happier than I have been in years with my current set up, having changed the tubes in my preamp and added MYE Sound spikes and stands to the Tympanis both of which have made huge improvements and the system generally sounds very good.

Nonetheless, I am getting a fairly flat image and still have a bit a glare -- even after adding the resistors in line with the tweeters. At any serious volume, it quickly becomes fatiguing.

Other than throwing out the SCD-1 and adding a turntable,

1) I plan to upgrade my mixed bag of old MIT, Monster and Home Depot hacked cables with Signal Cable copper speaker wires, interconnects and "magic" power cables all around

2) Wondering if adding a tubey type DAC - Audio Research? Audio Note? in line with the SCD-1 would make a big difference?

3) Wondering if the SP-11 is actually overrated and a bit hard sounding?

and

4) The Levinson 23.5 is the least likely culprit here, but still wondering if Bryston monoblocks or some other monstrously powerful amp might make everything a bit more effortlessly dynamic and therefore, perhaps less fatiguing?

Any suggestions greatly appreciated.