Is a noisy tube a bad sounding tube

I have a Conrad Johnson LS17 preamp that uses 2 6922 tubes per channel. When I turn the gain up to maximum there is some minor tube noise I can hear when I put my ear to the speakers on side only. I have verified it is from the preamp and not another part of the system. This is not audible at listening levels.

So clearly there is a noisy tube in that channel. I could try swapping out tubes to see which tube is the noisy one but since the noise is not audible when listening to music, I’m reluctant to pull the lid off the unit and mess around.

My question is, to those who may have had experience with tube gear is this.

Have you ever found that replacing a slightly noisy tube improved the sound other than reducing the noise? In other words, did the noisy tube degrade the sound in any way other than just the  added noise?