marcus4audio
Well-known member
- Joined
- Apr 23, 2013
- Messages
- 79
Hi guys, I mostly repair equipment but I decided to DIY API mic pre and everything works as a charm but when I put the top of the box i have small hum boost. It's the radiation from torodial tx to output tx and it's not terrible but I would like to keep it clean as it's possible. I measure noise approx -85db at max gain but when I close the top of the enclosure (aluminum) few db's at 50hz goes up. What can I do about it? Any suggestion? I tried to simulate hole at the place of the toroid tx (with few smaller sheets forming the top) and everything works as a charm. :-\