PM Guitar Tubes are designed to exceed the
original type specification and will perform better and last longer without
compromising the classic tonality of the tubes. All our
guitar tube sets are matched and graded on our unique COMPUTER TUBE
EVALUATION SYSTEM to ensure perfect balance and consistency.
THE PM GRADING SYSTEM
All PM Guitar
Tubes are supplied in matched Pairs, Quads or Sextets.
Our COMPUTER TUBE EVALUATION SYSTEM ensures each set is
matched to within 1 milliamp grid current. The Grade
Number on each set is NOT indicative of different performance
characteristics, it is a computer generated analogue of various
measurements.
Once your amp has been rebiased for a particular PM
grade you can replace again with a plus or minus 10 PM grade number set without
further rebiasing or loss of performance. Average PM power tube life is
2000 hours.
Check your amp's handbook before replacing. Incorrectly biased
amps reduce tube life and performance, invalidate our guarantee
and worst of all...sound bad!