Disclaimer: You may lose line voltage isolation by introducing it in the transformer secondary. I wired Neutral to the +5V winding and then the mains to keep the potential near ground in the transformer secondary. Also have the chassis grounded and the Furman power conditioner has ground fault monitoring. The +5V winding can easily handle the current so I am not too worried. Your setup may be different though.
When I had the chassis open I also noticed my Dueland preamp-to-phase inverter coupling caps were leaking all over the bottom of the chassis. That really pisses me off especially for what they cost. I had some Mundorf SIO 0.15uF caps and substituted those. Wow! I was missing a lot of low level detail with the leaky caps. And now have more bass as well. I think I am going to like the Mundorf SIOs. So today has been productive.