Linlai E 6sn7 tubes

Not pre-amps by any stretch but I have a pair of Counterpoint power amps UG'd by Alta Vista into NP-100s and currently being used as monoblocks. Will these tubes (they'll reqire a pair each) be as beneficial as in a preamp (my SA-1000 uses a solo 6DJ8)?

I just got my Ken Rad Vt231 black glass. Am  pairing it with my Linlais. I have the KRs on the buffer stage. Seems pretty ordinary to listen to right now. Havent felt the bass depth or  slam that is often associated with the KRs. Sounds  a bit warm.  Is it a case of burning it in? How long do these KR tubes take to burn in? Or should I put the KRs on the gain stage?  Or is it a case of poor matching as in the Linlais dont match well with KRs? My Linlais have also not been burnt in fully yet. Perhaps I should match the KRs with my Sylvania GTBs.  Any one mixed and matched Linlai E6sn7s  with KRs or KRs with Sylvanias. Appreciate your views.

@ram18

Chill out, you’ve got 4 new tubes installed which require break-in. True NOS Ken Rads need 50-60 hours and you know about the Linlai’s. You’ve got the tubes in the best positions for now. You'll soon hear the extended bass from the KRs.

"Chill out, you’ve got 4 new tubes installed which require break-in. True NOS Ken Rads need 50-60 hours... ’

                                                              +1

     This is a verbatim quote, from a letter Brent Jessee sends, whenever one buys valves from him:

                   "CARE AND FEEDING OF NEW TUBES: BREAK-IN
     New tubes need a break-in period before they can fully exhibit their true sonic character when used in audio circuits.

     Preamp tubes especially benefit from a good break-in. This period may vary widely, but NOS vintage tubes usually need at least 48 hours of use, sometimes up to 100 hours.

     New current production tubes need 24-48 hours typically.

     Good break-in can be accomplished by either leaving your tube unit turned on in a no-signal condition for 2 days, or you can just enjoy the tubes for several hours each evening and they will be broken in after several weeks.

     New tubes, especially NOS vintage tubes, may sound a bit edgy at first, but after the break-in period will mellow out and sound wonderful."

@ram18 -

"Havent felt the bass depth or slam that is often associated with the KRs."

     Has your system, as it now is configured (talking about components, speakers and room) ever produced the kind of Bass depth and slam, that you are attempting to achieve (or: recapture), with your tube changes?

     If you've already discussed that, elsewhere in the thread: my apologies.