EL34B replacement

[scunnerlad]

I gig with a HT40 and i have a gig later, i have been getting some unwaned noises ( power tube and main tube .... i have hammard this thing ) i am yet to order replacements but am worried for unwanted noise through the thing tonight when i play :/ , my friend to the rescue ! he has a spare set of tubes knocking around! yey! the 12ax7 no problems but .......

the main tubes are goove tube standard EL34's

my question is, can i replace a EL34b with a EL34? or will this cause an issue? is the HT40 cathode biased? a matched pair will just throw in ? or am I getting the tester out

any help would be apriciated

[LCW]

You might get a quicker response here...

https://www.facebook.com/groups/1428349310511261/

[scunnerlad]

You might get a quicker response here...

https://www.facebook.com/groups/1428349310511261/

thankyou LCW have requested and will post when joined

[zoziano]

I'm pretty sure that no amp mods are necessary, though a rebias probably will be. You should also make sure that they'll physically fit as KT-77s are larger than most EL-34s