Dumb tube question: ecc83 instead of ecc81 inside a tube mic

Here I have a tube mic, a T.Bone, i bought it 2 years ago, it's sound good for the price i've paid it...

But now (i never changed the tube) it sounds a little bit harsh on high frequencies... can it be the tube ?

I've found here a box full of new old stock tubes, ecc82, ecc83, ecl83, ect... no ecc81's, and the dumb question is...

Can I replace the ECC81 with a ECC83 ?

Sorry for the dumb question...
Neeeeeeeeeeeeeno

> it sounds a little bit harsh on high frequencies... can it be the tube?

Very unlikely.

> Can I replace the ECC81 with a ECC83?

Usually does no harm. Some circuits will work very poorly. Without knowing just how it is used, there is no way to answer that. My inclination would be to spend the $10-$20 to buy the right tube, instead of fooling around with wrong tubes.

IMHO, a harsh sound out of a mic is the capsule or grille, or possibly a mismatch between the capsule and electronics. The 'harsh' sound I associate with Chinese mics seems to come from the K87-like 32mm capsules, for some reason, and also from the grille shape and density. Changing the tube doesn't often change this. One exception - if you choose a tube with a higher miller capacitance (Cgp), you will tend to get more feedback in the amplifier, and if there is a mismatch in the output transformer, this can tame a tinny sound and make it more full. It won't get rid of the harshness without making it sound dull, IMHO.

-Dale