Tube Rolling Issues

We all know that the tube power amp consists of input tubes, output tubes and rectifier. The issues are as follow:

1. What is the tube life span for the above categories.
2. For tube rolling, can we replacing power tubes more often than input tubes and rectifier tubes.
3. If we change only power/ output tubes, will the combination of new and old tubes causing problem to sound reproduction.

TQ

1. Input tubes can last about 5,000 hrs, output tubes, 3,000 hrs. How long they last also depends on their quality of manufacture. My amp came with China made tubes and one KT88 tube blew within 2 weeks. They do sound not too bad though.
2. Yes if you want to but tubes do need time to settle. The tube's audio signature can only be discern after some period of breaking in and how long to break in varies. Speaking from experience, give or take 100 hrs. Btw, the difference in sound is greater when changing input tubes compared to output tubes.
3. Biasing would be a problem. The tubes start to wear out from day 1 of using the amp and over time biasing is required to keep the tubes performing at their optimum level. As I'm not the DIY type, I opted for an amp with an auto biasing feature which takes care of this problem.

auto bias or cathode bias means the same thing anyway. It is not completely proof and it is a good practice to check it occasionally for better performance. Contrary to popular believe tubes are costly maintenance issues, that is becos care is not given. for all you may know, tubes can withstand abuse more harshly than sands.

My monoblock power amp is using all together 26 sovtek tubes. So it seems that I do not have to change ALL the tubes one shot but 8 of the power tubes only. But how do we know when to change the tubes as I do not have a tube tester.

i dont agree that changing power tubes make less difference compare to input tube. my unison research amp sounds 200% better after changing from stock sovtek kt88 to reissue goldlion kt88. bass is deeper and tighter and the soundstage improves tremendously too.

Your ears are the best tube tester.

Every piece of gear is designed for a purpose. Changing components would yield a difference depending on the state.

Hi,

Would like to seek an advise. When shld we change the tube? Shld we wait till the tube blows out.

When the tube blows out, it does produce a pop sound, will it damage the other equipments (speaker/cd player etc)?

Thank you

I am tired of tube rolling on my headamp setup but happy with those that I am having.

A change of 4 tubes into a Klimo ViV Phono stage brought it back to life. The old tubes were only some 4 years old and sounded so drab and lazy prior to the replacement. Bunch of ECC81 and 6922 tubes.
At the rate I'm playing my amps, I'd change them every 3 years.