Use a 12AY7 JJ valve to reduce your gain
This is the perfect preamp valve to use if your amp is too loud. Many amps are simply too loud for use in a bedroom or small practice room so this is the perfect solution.
Use it instead of the 12AX7 in the V1 position. You can also use it in the V2 and V3 position as well on some amps.
It was designed specifically to reduce the gain without adding or subtracting from the original tone of your amp.