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 Mesa 22, Studio 22 or Studio 22 Plus 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.
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.