ARC ref 75 tubes 120 vs. 150’s?

Guys I borrowed a friends ARC Ref 75 With the KT 150’s installed. Loved the power and definition but the drums on Classic Rock stuff sounded unnatural & shrill on 8 ohms, bit better on 4 ohms but overall prefer the drum sound On my AR VT 100 my 2. Has anyone heard the AR Ref75 with the 120 tubes? If so how did the sound compare to the 150’s?
thanks