I'm not sure if I understand your question. Are you asking if a Precision AC is adequate or too much to use on a QLS-9? Synergistic suggests to try their T3 UHC (or even a T3 if its not a huge power demand like MPC's) and Precision AC to be used on their power conditioners and choose the one you prefer. I prefer the Precision AC. In my system, its more extended and has better clarity, soundstage and presence. It projects its qualities to all components. Also, Synergistic does make suggestions in its AC conditioning section on their website (The comments can be applied to the QLS conditioners as well). I found that the T3 UHC has a warmer presentation and is more tube like. The bass is heavier. I use a different Synergistic cable on most my components. The PC chosen compliments that piece of equipment.
If you E-mail or call Synergistic they are more than willing to explain in great detail about all their power cords and their applications. They do not always suggest the most expensive but give you the option to decide and will suggest you to try a few first in your system. Find a dealer that can lend you them before you buy.
