Wiim ultra causing hum

[Deleted member 26622]

@jdjd1 have you tried a rca ground loop isolator?

If not, you could try a cheapish one to see if it fixes the issue, and if so, look for a better quality unit if you feel it’s required.

 

[slartibartfast]

WiiM Amp Ultra and Sub Pro are only WiiM products with 3-pin power plug. Knowing a ground loop as potential issue, I don't understand why other WiiM products do not have power plug with ground pin.

Ground loops are more likely with a 3 pin plug. How can a ground loop exist if there is no ground connection?

 

[Vladetz]

Had almost same issue. Isolated ground on sub power cable and hum is gone

 

[jed1]

I would be very careful about disconnecting ground from devices like amp and active subwoofer.

 

[Vladetz]

I would be very careful about disconnecting ground from devices like amp and active subwoofer.

I don't have proper grounding in my home anyway

 

[incans]

FWIW I am having similar noise problems with my WiiM Ultra to yours, but with my main speakers (which are active studio monitors), not the sub.

Unfortunately my monitors are fixed gain, they always run at maximum sensitivity ("full volume"), so it's not possible to use the workaround if dropping the speaker gain to reduce the noise floor.

 

[anonyless]

FWIW I am having similar noise problems with my WiiM Ultra to yours, but with my main speakers (which are active studio monitors), not the sub.

Unfortunately my monitors are fixed gain, they always run at maximum sensitivity ("full volume"), so it's not possible to use the workaround if dropping the speaker gain to reduce the noise floor.

i had a very similar issue as yours -
my Ultra was connected with RCA out to 3e Audio A5 amp, sub out to QB12 sub, and a low hum (probably ground loop noise) in the (passive) speakers. i managed to isolate the issue to the sub out RCA connector, as once I disconnected the RCA, the hum stopped.
needless to say, all equipment were connected to same power splitter. tried switching RCA cable(s) for the sub, with no change.
i workaround this issue with connecting optical out from the Ultra to SU1 DAC and from there RCAs to the 3e audio amp (hum stopped).

this is where things get "interesting" as i bought Vibelink amp and connected it with RCAs to the Ultra - no hum..!
the Vibelink uses 3 prong power cable with ground connection , unlike the 3e audio A5 which uses an external power supply with 2 prong . I can only assume the 3e audio PS was causing somehow the noise, but I can't tell for sure.

does your monitors have optical (or coxial) input? might solve your issue