Having lived with this amp for about five years, I think you need to look at a different pair of speakers.
Also, the amp sounds much better with either JJ KT88 or E34L tubes. Much sweeter and alive.
Personally, like with any amplifier, I have found some speakers to make it come alive, and others leave it to sleep. Along the way, I paired it with many different loudspeakers. The best combination was with my Coincident Digital Master/Troubass subwoofers, running either of the JJ tubes. It simply played the music exactly right, and the resolution, refinement, dynamics, and believability were wonderful. I have never before used the word "perfect" to describe anything audio, but the tonality was perfect. THE absolute best sound I have ever had.