F-50 Tubes & Bias

[boogief50]

If I change the 2 6L6's from say "red" to "green". Do I need to re-bias the amp to accommodate the new color code ?

Also. I know the F-50 has set bias. What is it ? and should I get the bias checked on the reg to make sure its still at factory setting.

Thanks.

 

[Fred2202]

If you are using Mesa branded tubes you should be good to go. Just plug them in. If you have lingering doubts a tech could probably check that the amp negative bias voltage is still where it should be. It would take a total of about 5-10 minutes on the bench so it should not be that expensive. I am rehabilitating a 50 Caliber at the moment built in 1989. Had to change out a few of the carbon comp resistors in the bias supply as they had drifted a little. Negative bias voltage was off a little bit. Put metal oxides in this time so that section of the amp should be good for many more years.