Mesa Boogie 5881 STR 425 (DUET)

Our State of the Art Tube Tester

With the brains of a computer and the ears of a musician, Robotube runs a battery of seven exacting tests on each power tube and analyzes performance so thoroughly it can even predict the tube's lifetime. Designed by Mesa Engineering and built for us by an aerospace firm, Robotube is a one-of-a-kind machine and easily the most modern and powerful in the industry.

If you play at moderate levels 10-15 hours a week
* Power Tubes will generally last 1 - 1.5 years.
* Preamp Tubes will generally last 2 - 3 years.

Signs of Wear

Power Tubes:
• Low end response is not as clear and distorts earlier.
• You turn your amp’s master volume up to hear the level that you are used to hearing.
• Eventually you will hear 'crackling' 'popping' sounds, often accompanied by:
• 'Swelling' volume levels.
• Buzzing.

Preamp Tubes:
• Hissing, 'shooshing'.
• Sputtering, 'grumbling'.
• Microphonic squealing (feedback type sound).
• Loss in signal in one or more modes of the amp (channel, reverb, fx-loop).