I am using a Topping D10 Balanced with a Sabaj A20h and I just found something really weird, I am picking up FM radio interference but only on 3 separate volume spectrums, between -99dB and -85dB, between -3dB and -1dB, and at 0dB.
Between -99dB and -85dB is the strongest, I can no longer hear it when I increase the volume to -84dB.
Between -3dB and -1dB it's still there but not as noticeable due to the higher noise floor, I can no longer hear it when I decrease the volume to -4dB.
At 0dB it's a bit lower, but still there.
I am using the single-ended output and the FM radio interference can only be heard on the Left channel.
It doesn't matter which input is selected on the amp.
It doesn't matter which gain setting is used, although it is the only thing that seems to have any effect on the volume of the FM radio interference.
I am using very short 30cm XLR>6.35mm cables without any adapters, the interference only goes away when I unplug both cables even though it can only be heard on the Left channel.
There is nothing connected to the amp's single-ended input.
Touching the Topping's chassis or its USB cable or moving the stack seem to alleviate the problem, but what is the explanation for this phenomenon and what can be done to mitigate it? And why exactly only between -99dB~-85dB, between -3dB~-1dB and at 0dB? This amp uses a stepped resistor ladder controlled by relays.
The radio station that I'm hearing is transmiting on 103.40MHz or 105.00MHz, not sure which one, or maybe on both.
Between -99dB and -85dB is the strongest, I can no longer hear it when I increase the volume to -84dB.
Between -3dB and -1dB it's still there but not as noticeable due to the higher noise floor, I can no longer hear it when I decrease the volume to -4dB.
At 0dB it's a bit lower, but still there.
I am using the single-ended output and the FM radio interference can only be heard on the Left channel.
It doesn't matter which input is selected on the amp.
It doesn't matter which gain setting is used, although it is the only thing that seems to have any effect on the volume of the FM radio interference.
I am using very short 30cm XLR>6.35mm cables without any adapters, the interference only goes away when I unplug both cables even though it can only be heard on the Left channel.
There is nothing connected to the amp's single-ended input.
Touching the Topping's chassis or its USB cable or moving the stack seem to alleviate the problem, but what is the explanation for this phenomenon and what can be done to mitigate it? And why exactly only between -99dB~-85dB, between -3dB~-1dB and at 0dB? This amp uses a stepped resistor ladder controlled by relays.
The radio station that I'm hearing is transmiting on 103.40MHz or 105.00MHz, not sure which one, or maybe on both.