I own an iFi Pro iCAN Signature amplifier coupled with a Topping D90se DAC. I have the two connected via good quality, balanced XLR cables. I noticed recently that if I stack the two with the amp on top, I’m hearing a low-grade motorboating oscillation on the right channel when the amp is in solid state mode, and the noise curiously transfers to the left channel when I switch to the tube circuit.
Strangely, when I move the amp forward about 3 inches so it is overhanging the DAC, the noise ceases. I’ve reproduced this exact same behavior on multiple attempts and I can only get a quiet sound when the amp is not sitting directly on top of the DAC. Also, raising the amp up on a riser does not resolve the noise (unless it is positioned three inches forward on the DAC so they’re not evenly stacked).
Can anyone offer some possible explanations for this please? I would consider a bad filter cap if it weren’t for the fact that it switches channels and disappears with amp placement. I tried removing the Bluetooth antenna on the DAC with no improvement. Help needed!
Strangely, when I move the amp forward about 3 inches so it is overhanging the DAC, the noise ceases. I’ve reproduced this exact same behavior on multiple attempts and I can only get a quiet sound when the amp is not sitting directly on top of the DAC. Also, raising the amp up on a riser does not resolve the noise (unless it is positioned three inches forward on the DAC so they’re not evenly stacked).
Can anyone offer some possible explanations for this please? I would consider a bad filter cap if it weren’t for the fact that it switches channels and disappears with amp placement. I tried removing the Bluetooth antenna on the DAC with no improvement. Help needed!