Hard to say with so little info, as valves have no 'sound' of their own (unless dropped on a hard surface).
In a properly designed amp, using valves within the design tolerances, there should be very little difference between brands.
In less strict designs, especially those meant to add colour/warmth/character ie distortion, there can be very perceivable differences.
Long time ago I developed a dislike for the small plate East German ECC82 as it didn't sound well in *my* amp at that time, where the long plate Philips did. Thinking back, I'd like to know why there was a difference, but alas, that amp is no more.
I have no experience with the various JJ versions or La Radiotechnique.
Since the ECC82 is not the most linear type, switching to a 12BH7 or rewiring for a 6FQ7/6CG7 could reduce distortion, if that's what you're after.