Audible hiss when using toslink on my s50 pro +

I have an audible hiss when when no content is playing but only when I am using the Toslink input through my S50 pro+. Content plays normally but when it stops then my speakers have a low level noise that is pretty annoying.

The sound is present even when i lower the volume of the S50 pro+ to 0

The hiss is not present when I am streaming through the S50 pro+ directly.

I use the S50 pro+ as a preamplifier for two channel audio when I am using my LG projector.

Please suggest possible solutions and reasons for the issue.

Setup details:

Nvidia shield connected to projector through HDMI

LG HF85LA projector connected to S50 pro+ through optical

S50 pro+ connected to emotiva Basx A2 power amplifier

Everything powered by the same powerstrip

No antennas in close proximity

S50 pro+ used to attenuate volume

I’ve got the same problem. Were you ever able to find a solution?

Yes. I disconnected my arylic and bought a marantz nr1510 for my projector. I now only use the arylic for music with my vintage NEC integrated amplifier. weirdly I get no noise when it is used as a streamer

I have the same problem, low level noise present when playing music. Making it kind of useless as a pre-amplifier directly connected to a power amp 150W.

The weird thing is when increasing volume the low level noise does not increases. Turning the volume to zero the noise is gone.

I tried the digital output to a seperate DAC, but also low level noise is present. Make me believe it is already present in the digital domain.

I swapped my S50 PRO+ for a new one, which had the same problem.

My workaround is to place a pre-amp in between so you can have max volume out on the S50 PRO+.

The one thing i want to try is if a better power supply has any positive effect.