All of the Retube Kits below are Low Output kits and these kits use the JJ EL844’s for power. These are completely different tubes than the stock tubes your Express 5-25 came with. The JJ EL844’s are a proprietary tube that JJ Electronic built at the request of Eurotubes. They're totally plug and play with no modifications required.
These kits are suitable for both the original Express 5-25 and the Express 5-25 Plus.
The dissipation of the JJ EL844 is 25% less than a standard EL84 so using the EL844’s will reduce the power a little in your amp.
All our Mesa Retube Kits include power tubes that are hand selected to run perfectly in Mesa amps. We have extensive hands-on experience measuring the fixed bias points in these amps and what grade of tubes will achieve optimal performance.