Name:    Steve Kennedy
Email:   steve@pacair.com  
Subject: 212-HD 130 one last question
Thread:  77
Time:    Thu, 10 May 2001 02:32:52 GMT

I didn't want to imply that you HAVE to rebias your amp. Music Man amps are biased on the "cold" side (10-15mA) because of their high plate voltage.


MM amps use 700V of plate voltage (which is almost double that of a "normal" tube guitar amp). Because the voltage is doubled, the tube's quiescent bias current is half what it might normally be... about 15mA.


Unless you notice short tube life ot hot output tubes it is probably fine and close enough. The output tubes are supposed to run almost cool enough to touch when the amp is sitting idle because of the low bias current, which leads to longer output tube life.


Steve