No, mains runs at 230V in Europe, but as said by sibling comments, after the power transformer and rectification, HT1 (the primary high tension power bus, usual

No, mains runs at 230V in Europe, but as said by sibling comments, after the power transformer and rectification, HT1 (the primary high tension power bus, usually feeding the tubes in the power section) can get in the 300-500V range in some amp designs. I knew from schematics and calculations it'd be about this high, but seeing the actual 400V value on my cheap multimeter sent shivers down my spine. Also I remember accidentally shorting the wrong wires while taking a measurement and blowing a fuse. Fun times!