Tube Nube questions


I am beginning to roll output tubes in my Primaluna Prologue 2 . What is an average amount of time for new tubes to burn in ?

When I have a handle , after burn in , on the new tubes how long should I need to warm up the old tubes on a warmed up amp to make a fair comparison ?

Thank you .
saki70
I allow 24 hours break in time, especially for power tubes. You'll get a good feeling for tone changes with small tubes after a couple of hours, but power tubes really need a bit more.

Re-installing old tubes in an amp do not require breakin beyond the normal warm up time required by an amp (etc).

BTW, something worthwhile to consider especially if you are listening to tubes which have a great reputation for working well with your amp but for some reason don't, is to check out the bias settings with a meter ala instructions put out by Kevin Deal. I'm using 6L6's in my PL5 in preference to every thing else, but prior to tweeking the bias they sounded anemic. I did this with my PL1 as well but the best tube in it so far is still the EL34. FWIW.
I agree with newbee within an hour. My figure is 25 hours for a set of KT88's.
Ok thanks .

Just to make sure that I have it right . You are saying that putting cold tubes into a 'warmed up' amp will still take the same amount of time to come to full sound as when the amp and tubes are both cold ?

By the way , where does Kevin Deal have the biasing procedure printed .