Dear HiFi Rose users
Thank you for sharing your feedback.
Transformer hum in products with a linear power supply can be affected by factors such as AC power quality, DC offset, and the installation environment. Therefore, the perceived level of hum may vary depending on the conditions.
For the RS451, slight transformer hum is a characteristic of the linear power supply. If the hum cannot be heard from approximately 1 meter away, we consider the unit to be operating within normal specifications.
We appreciate all of your feedback and will share it with our development team for future consideration.