Blown tube issue


So one of my Tung Sol EL34s blew last weekend after 6 months and I’m not running them constantly. Manley is replacing for me.

My question is : is it ok to pop in a random EL34 in the interim and how does that affect sound ? Same brand better ? These tubes I bought from Manley are all bias numbered . Not sure if there is an exact slot order to the numeration . 
Another thing that concerns me is I bought the snappers used from some Agon user who replaced/upgraded the caps . I’ve been told depending on his work this could be the reason I’ve already blown 2 power tubes in 1.5 years ? Anything I can be aware of appreciated !

my setup :
manley snappers
Manley jumbo shrimp pre
VPI super prime scout
allnic h1202 phonostage

tommypenngotti

Showing 2 responses by millercarbon

To blow a tube in six months is unexpected, and unfortunate, but unfortunately not unusual.
What lewm said. Tubes are just plain unpredictable. New or used, biased or not, they can just blow, or last forever, and I have seen it all. I've had three brand new Preferred Series tubes from thetubestore.com blow within weeks, and I've had the most inexpensive JJ tubes run so many years they very gradually became dull just like lewm said. Only the change was so gradual over so long I didn't even notice until the new tubes went in and then WOW! (Sorry for the hyperbole, wow!)