Decent Bass & Mids, compressed highs on Analog

Challenged with the early phases of analog setup.

Received criticism for my system having very limited extension in the highs.

It's an integrated system: Aurum Acoustics CDP and Aurum mid and highs amps with 300B and 6SN7 tunes, solid state bass amps (all on the same chassis). The front end is a Technics SP10, Acos Lustre STA-801 arm and Dynavector 20X-L cartridge through Harmonic Technologies Silver phono cable to the onboard phono stage.

CDs have excellent presence, giving a balanced sound spectrum with good high frequency response and uncommonly three dimensional presentation.

The cantilever on the cartridge is not dead-center, and though I've tried to adjust for that by mounting at an angle to compensate, alignment is one possible flaw.

During our session we swapped in a different PC, and though the presentation shifted toward the upper frequencies and presentation opened up somewhat, the PC sounded quite colored to me. My standard PC is top of the line Furutech, and has given very even and coherent results with CDs.

Any thoughts or suggestions would be most appreciated.

Thanks in advance,

David