"I bumped in a preowned ARC PH5."
It kind of sounds like you bumped one into your system. I don't know you meant something else. Your Delos is 6mv. That's a low output cart. The PH5 isn't made for such a low output cart. You should use a HOMC or a MM. Head amp= SUT, sorry. The ARC is fairly entry level component. If you are going to use a tube phono stage with a low output cart, it needs to be something really good. The Kline you have now is a much better match for the Delos.