Originally Posted by sixstring531
Not home to test - but here's the scenario: (Bad Cat Black Cat 30 - hot running tonemonster)
Newer JJ Power Tubes as of late January 2012 - play about 3 hrs a week - power tubes always last the whole year (I change them every year)
Went to practice Thursday and felt like I had to turn it up a notch or two louder to get the oompfh I was used. I also felt like I lost some mojo - can't really describe it in tone other than "slightly thinner and not as big". No noticable (visibly or audibly) problems. I changed the main preamps (not the PI) no change. I put the year old power tubes in and thought it sounded slightly better, but I was still certain I was missing something.
I went ahead and played it Sunday - sounded fine, but again, thought it lacked a tad.
I haven't changed the PI for two years now. It's the 12ax7LPS James told me to put in it and I have an email into him to see what he thinks.
I just didn't know if a dying PI died or gradually got weaker....
the LPS are more fragile and tend to be microphonic because of the larger plates.
i would swap the tube and see how it goes.