Finally, I change my main transformer orientation, from horizontal to vertical. Not really easy to mount this giant transformer vertically. But here is the result. I’m quite sure I love this new orientation than before 😉
Actually, the best solution is if you can “sealed” the two side of the transformer by a metal plate (either aluminum or copper). But since my DIY chassis is completely “rubbish”, then I don’t think I can do that. Just prepare for a future plan, so I keep the vertical mount position now.
This Z11 based iron with Australia/Germany copper wire is rated around 150VA or more. With current load about 110VA from my preamp, this giant is completely cool for over 8 hours non-stop performance. Damned, I do love this transformer! Sadly, not easy to get similar transformer in the near future (Z11 is quite rare here and expensive).