This Chinese made EL34 has found favour with many manufacturers.
When you select replacement output pentodes check the physical size/style of your existing valves….they come in at least 3 body shapes. The valve has an overblown midrange which gives it a warm sound. These valves are a good upgrade in any amp if you find the sound hard or harsh. This is due to the smooth but recessed treble. The valve also clips fairly early and has a nice overdriven sound.
PS such devices are banned from being manufactured within the EU…so all valves on sale now come from China or Russia…or are VERY old stock. Old stock valves will be prone to being ‘soft’…i.e. air will have slowly diffused into the envelope vacuum….BEWARE.