Q: Am I only the one having 1.5kHz and 3kHz rogue freq?

It’s been almost 3 months since I started using the Quad Cortex.

While using it, I discovered that there were rogue frequencies at 1.5kHz and 3kHz, which didn’t exist in my guitar + pedalboard setup. So I inserted a 3-point EQ to cut out those rogue frequencies. I compensated for the reduced sound with a boost to balance it out. Interestingly, the rogue frequencies were precisely at 1500 and 3000 Hz.
At first, I suspected certain presets, but all of them had the same rogue frequencies. Even with all effects turned off and using pure clean tone, it was the same. The rogue frequencies were there.

Also, when using the LED blink metronome, another rogue frequency occurred, so I turned off the blink as well. LED metronome is a nice feature to have, but it seems to generate a subtle noise inside the machine.

These rogue frequencies were particularly noticeable during natural sustain fade-outs at the end of songs. Using an adaptive gate made the disturbing sound and fade-out appear, and then everything disappeared abruptly at the end, making it very messy. Eventually, I solved it by using EQ.

But is it just me? How about other Quad Cortex users? I’m using the latest QOS 3.x version. (I update immediately when an update is available, so it’s probably the most recent version)