6L6 440 vs 6L6 430

[oneamongthefence]

I replaced two of my power tubes yesterday simply to switch old ones out for new ones. my previous ones were 6L6 str 430's and the new one's are 6L6 str 440's. Now im guessing that the 440's are just the newer versions of the 430's so it doesnt matter if u mix the two? One thing i have noticed is that the first 440 looks like its burning hotter than the other 440, and the 430's look fairly dim. Is this normal? my amp sounds good still, and i didnt have this problem before i put the new ones in...so im just wondering if the 440's looking like they are burning hotter is normal? im half tempted to put my old power tubes back in so i dont screw something up.

 

[ANIMATED SUSPENSION]

Yes you can mix them as long as you have them fitted in sequence XYYX. The brightness you are seeing is just the heater element I would guess, the 440 does seem to glow more than the 430. As long as the plates aren't glowing...!! :shock: