Shrill high frequencies

The solution was to plug the Isotek into an Audioquest Power line 2 with a Nordost QRT inserted.

Thanks to all for sharing your mighty brains and happy listening! 

Magnum Dynalab MD 108 tuner, Modwright modified Sony HAP Z1ES, Audible Illusions Modulus 3A with all factory upgrades, either an Atma-Sphere S-30 mk 3.3 or Luxman MQ-88UC amp KEF LS 50 speakers 2 REL Stentor subs. ICs are all Cardas Clear, speaker cables Nordost Frey 2, power cords Shunyata. 

At your suggestion I changed the power cord from that provided to Shunyata Delta. No joy. Maybe break-in time will help. 

Amp is Luxman MQ-88UC, preamp Audible Illusions Modulus 3b factory upgraded, sources Modwright modified Sony HAP Z1ES,.Magnum Dynalab MB 108 tuner. All IC cables are Cardas Clear , Speaker cables Nordost Frey 2. Speakers are KEF LS 50 or Goldenear Triton 1, subs REL Stentors.