More power for better sound at low volumes?

I like the comment about power supplies. We've been using HEXFREDs for 17 years; getting rid of the noise floor is a big deal when you have to run the amp at lower power levels.

In amplifiers if there are published specs, look for the distortion to decline linearly towards zero without a dip and increase as power decreases. You will find that this rules about about 90% of existing amplifiers, but if you play the amp at low power a lot is well worth while; IMO that is true even if you don't.

When you operate a high power amplifier at low power levels quite often you have higher levels of distortion. This is because most high power amplifiers are push-pull and with rare exception, most push pull amps (tube or solid state) will have their lowest distortion at some point well above zero watts and then the distortion increases again as power continues to decrease.

At low power in particular, it really is that 'first watt' that makes the difference! Due to the ear's masking principle, if higher distortion is present, detail will be obscured IOW such an amp will be less detailed at lower volume levels. Also as others have pointed out the noise floor will be higher too.

Amps that do not exhibit this dip in distortion, IOW amps that have a linear decrease in distortion as power goes down to zero, will have unmeasurable distortion as power levels fall below 1 watt. They fall into two categories: either SET, or fully-differential with little or no negative feedback.

I can go into the why of this if anyone wants but it gets technical.

Unsound, more power in the amp will not reject external noise. The way to do that is to have a fully differential balanced circuit (whether tube or solid state).