With the exception of the ZENmini and the PULSEmini, all current Innuos products include a linear power supplies which include a toroidal transformer. Toroidal transformers in general can have a small amount of hum which should not be listenable over 1m away from the system. There are factors though that can contribute to higher hum noise such as:
- High mains voltage (above 240V)
- Presence of DC power in the AC mains installation. This can be caused by other devices such as LED/Fluorescent lights
What can be done
There are two things to try:
- Check the mains voltage. If it’s too high this should be addressed by an electrician
- The presence of DC power in AC mains installation can be prevented with a DC Blocker such as this: https://ifi-audio.com/products/dc-blocker/ Some customers have already used this successfully.
If the above doesn’t help the next step is to take the server to a different house or their Innuos dealer and check whether the hum also present there and it’s audible more than 1 meter away from the system. If that’s the case please contact us on email@example.com.