Tube change question.....

[HarpmanBob]

Hi. Bob from Joplin, MO here.....pretty new, not many posts so far.
Use my 1959 Bassman for playing bass.

My question is: the amp has a pair of 5881 tubes now.....if I
wanted to replace them with 6L6s, would the amp need to be
re-biased?? Also, would that switch even be worthwhile?

Thanks for any info.

Bob

[boobtube21]

Don't you know the bassman is a guitar amp?

You should check your bias every time you install new tubes. Kind of like checking the tire pressure when you put on new tires. Not sure what the difference is between 5881 and 6L6's, if there is any. However if you're stepping up from Groove Tubes/Sovteks to JJ's or Svetlana/Winged C then yes, it is worth while.

I'm a little confused there actually-according to "the tube store" 6L6/5881's can only handle 400 plate volts but on the 5F6-A schem, you can see 430 volts headed for the power section...and it specs 5881's. Hmmm...

[steve25]

If you step up to matched JJs or wing C and then check and re- bais the amp if need be, you will gain a tad more punch and clean head room over those 5881s in the amp now.