Your tubes shouldn't be glowing at all, nor should your amp work at all.
You have nothing connected to the hot terminal on the incoming AC. You have part of your primary winding wired to the chassis of your amp.
If your tubes are lighting up, you either have a hot/neutral reversal at your outlet, a hot/neutral reversal in the power cord, or some other issue. You are also relying on the earth to carry all the current the preamp is using, so a GFCI outlet should trip instantly once this is plugged in.