Audio Research - should I replace the valves?

if u want NOS, try the top 3 dealers: jim mcshane, brent jessee or andy at vintage tube services unless u need new stock. jim carries a good bit of new stock, but i dont know if he carries what ur usin.

I've owned and steadily enjoyed a McIntosh MC275 tube amp and C2600 tube preamp since late 2017.  I've never tried to estimate the cumulative hrs. of listening, but it's up there.  I purchased a complete replacement set of replacement tubes for both components from McIntosh a couple of years ago, and stored them away for eventual replacement. I don't recall seeing any bias adjustments and frankly didn't know it was a thing.  I suppose it's time to swap them out!

@rickisme  , I just did a cursory search & I am picking up that the newer 275s are self biasing.  Other wise, occasional checking & adjusting the bias of output tubes is a MUST.  Especially after installing a new set.  Your owners manual should clarify that for you.

@ghdprentice upscale audio quite ("paused") sellin tubes this past april. 

@cey  , when was the last time you checked?  Uncle Kevin has been selling tubes again for a while now. 

hey there @immatthewj thanks for catchin that so quick!

i just re-read my emails and revisited the website. im mistaken.

seems even tho theyre sellin tubes again they never took down their "we paused out tube selling" page. 

thank you my friend