Re: 50 watts or 100 watts?
...in 30 or 40 years they'll still go deaf and be unable to hear what their wife is saying to them from across a small table in a slightly noisy restaurant.
It's not always a bad effect
Lew, you're absolutely right anyway, it's the best advice some can get:
PROTECT YOUR EARS!!!!!
If you're a musician you'll need your ears. if you shock your ears with too much decibels, your nerves there will die slowly and they will stop working properly (or at all) after a time and you can't be a musician anymore. It's all up to your plans: how long do you want to play music? 10 years? 20? 30? 50 perhaps?
Back 2 the track:
On open stages clever placement and careful monitor mix is the key. Indoors it depends only on the actual room acoustics and an enjoyable sound (and volume levels) for the audience.
You can do the job with a 15W little tube amp if you put it the right place and 10 Marshall full stacks can kill your performance if they outmask the other instruments. THINK before act.
amps:
If it's a Vox AC and EL84 tubes, 30W power is more than enough. Cranked up all the way it will kill you. And, your indoors audience.
If it's an EL34 power amp, 50W should be enough. The power section will break sooner and basically that's what you need for a perfect Marshall crunch.
If it's a 6L6 power amp, 100 watts shoud do it, but NEVER CRANK IT UP ALL THE WAY!!! It will overkill your ears after a time. These power amps are usually about fine and mean preamp section and clean delivery, plus much headroom in the output stage.
In my experience if it's solid state you'll need 200+ watts, preferably MOSFET. It has nothing to do with volume, only tone. A 200W SS amp has enough headroom to sound good halfways ('bout 100W). Since SS power section has different characteristics from tube stuff, approx. about 60% of its power rating it starts to ruin its tone, partly because of the way you hear things, partly because of some unwanted enhanced transistor distortion that is omnipresent.