Kenwood KA-8100 integrated Amp

I can’t speak for your amp but I have owned the LS7 and I would start with that first. I found the LS7 to be lifeless and really didn’t shine anywhere and I tried NOS tubes. ARC knew this pre wasn’t competitive  and probably has the shortest lifespan of any ARC preamp. I’ve read positive reviews on the Wyred amps so I’ll put my nickel on the LS7 is the weaker link. I have a hard time thinking a 70’s Kenwood integrated is going to outperform more modern separates. Try a different preamp; a lot of them out there that will outperform a LS7 in my opinion for the same money.

So, what I think you may be hearing ... there are a number of youtube videos, with the head of Zu Audio, as well as the reviewer, Corey Greenberg, where they talk about amps that match up well with Zu speakers.  I believe that they were referencing the Omens and the Dirty Weekenders.  Both were saying that the older integrated amps and receivers do very well with the Zu speakers.  In fact the reference was to try an old receiver that you may have in the attic.  Corey was also talking about pairing them with the NAD 316 BEE.    

I took delivery on a pair of Zu Dirty Weekenders about a month ago and I am having a blast with them.  So far, they are sounding better with my tube amp (Prima Luna Prologue 5) fronted with a Musical Fidelity CD PRE 24 than with other solid state amps that I own.  Even my wife commented the other day how much she liked music played out of the Dirty Weekenders ... much more alive.  She rarely comments on anything other than speaker cabinet finishes and how much stuff I have around.  

I would stay put with the Yamaha, at least as long as I was holding on to the Omens.   

Rich 

Rich, Thanks for your input.
I want to mention that I don't have a Yamaha...I have a Kenwood KA 8100 with dual power supplies .

Thank you to all that responded to my inquiry.
I appreciate you all.