Does using XLR cables (double voltage output) mean I can use lower powered amplifiers?

Paul McGowan claims that tube amps can't be balanced.

+1 @cakyol

MC, you should change your avatar to a little knitted black and white bear with pins stuck in it…

Hello,
Please match your amp to your speakers regardless of your sources. It should be a slight benefit to have XLR as a volume increase. Put it this way. Regardless to whatever you input into your iPhone it’s not going to power your speakers. I just don’t want you to damage your speakers. I have been having fun demoing the Hegel V10 phono preamp through using XLR to the preamp. I am still happy I have 100 watts A/B to push the speakers. It make the music sound live. The headroom is incredible. For $1500 MM/MC XLR phono stage it’s really good. I am also demoing the Sutherland Little LOCO phono stage. Due to the input being current driven and 0 input voltage you can hook up two MC turntables at the same time. Imagine; two tables and one phono stage. Stereo only, no mono unless you buy the mono version. I actually called Sutherland and received this information last night. 
If you reside in the Chicagoland area you should try them out. https://holmaudio.com/
You should call and ask about their hours or the amount of time you can have something out on demo. I just like that they let you try before you buy. No more buyers remorse. Plus, If you can’t demo stuff how do you know how it sounds in your system and even more important your room. Sorry for being long winded. I just don’t want you to damage your equipment. 

Hello thegreenman!  All it means is than you can turn the volume knob on your amp or pre amp down a bit. The output power of your amp is not affected. It could be that you will have less hum/noise in the signal because of the balanced connection. Enjoy the music!