# Marshall Origin 20H Tube replacement



## Asifur (Oct 5, 2018)

Hi,

I play through a cranked Marshall Origin 20H with a G12 Greenback speaker. I was planning to replace the current EL34s with 6CA7s once they wear out. Is this a feasible option, or would I have to adjust the bias?


----------



## nonreverb (Sep 19, 2006)

I believe the 20H is cathode biased therefor, no adjustment is required.


----------

