Amplifier Intermittent noise in ZD3+ZA3 combo

[sbiehe]

I have a ZD3 hooked up to a Chromecast audio via TOSLINK and a Sony TV via HDMI. The ZD3 is sending audio to a set of ZA3's in RCA-MONO configuration. The ZA3's power up on a 12V sync signal from the ZD3.

• Every once in a while, I hear a noise in the left channel only. The sound is attached as an audio recording done on my iPhone.
• The intervals at which this noise appears, fluctuates a lot. During a test, I recorded 25sesonds, 37s, 65s, 18s, 46s, 63s, 10s, 54s, 64s, 4s, 60s, 58s, 6s, 64s, 50s, 15s and 64s between the appearance of this noise, which was the same every time.
• The noiselevel is independent of the volume setting on the ZD3.
• The noise is also there when the 12v trigger cable is unplugged
• I haven't detected it when I unplug the RCA cable between the ZD3 and the left ZA3.
• After switching the whole set on and off, the noise doesn't appear until at least one hour later.

Could this suggest that the ZD3 is at fault? Any ideas?

 

[moonnn]

Did you manage to find a solution to this?

I’m experiencing the same issue with my ZA3/ZD3 combo. The noise I hear is very similar, though not identical, and like you I’ve noticed that its volume does not change with the ZD3’s volume control.

I’ve narrowed it down to the ZD3. When I swap the left and right inputs on the ZA3, the noise moves to the opposite channel. That suggests the issue is upstream of the amplifier. It also occurs regardless of whether I’m using HDMI or USB, so it doesn’t appear to be source-related.

 

[sbiehe]

Hi Moonnn
I have removed my Bluetooth antenna from the ZD3 and moved the ZD3 away from the small switch-mode supplies and other auxiliary devices lying nearby. This seems to have cleared the issue, but if I for some reason fumble around with e.g. my Chromecast Audio which is connected to the optical input, I have to be careful not to displace it behind the ZD3. Otherwise I once had the issue re-appear. But I fixed it again by simply creating ample free space around the ZD3. It seems to be quite EMR sensitive.

I now have the volume on my two ZA3's turned all the way up with no noise, clicking or hissing issues whatsoever.
But I'm still not totally convinced about the build quality of these products.