I'd like to point out that it's fairly impossible for a moving coil dynamic mic to have a grainy top end.
When you hear that grain you are listening to the character of the preamp.
Hence the recommendation that one seek out and use a preamp that really likes moving coil dynamic mics if you wish to hear the full benefit of using a moving coil dynamic mic.
The transformer coupling is the key... and it has to be the right transformer... just looking at the impedance spec isn't enough.
The transformer has to actually have have an impedance
curve, (a.k.a. frequency response) that encourages the mic to sound open, silky, and smooth.
It's the exact opposite characteristic than you will find in a modern IC based, servo coupled, "flat" frequency response design and it's not quite what you find in today's premium transformer coupled boutique gear either.
The transformers I am speaking of were tailored to the mics by ear rather than an idealized broad flat frequency response.
You would get the transformer in a metal can with octal plugs and you'd plug it in to the back of the Ampex preamp... if you had 6 transformers you could try them all and use the one that really sounded the best for an announcers voice.
Back in the day, they built that gear by the boat load.
best regards,
mike