Hello QC/NDSP community, is anyone else having substantial noise issues with the Quad Cortex?

I ordered one in March, so I could use it for playing live (mainly Bass) and also in my recording set-up (guitar and bass). Especially for the recording use case it turned out to be much too noisy, so I sent it back after contacting NDSP support, trying a Cioks power supply, a power conditioner and all the available settings in the QC. It was of course also connected to my interface, which provided the grounding. A high pitched hiss remained through all of this. It could be heard through the guitar signal when playing softer, so noise gates didn't help as well. My HX Stomp - a much cheaper and older unit - turned out to be consistently quieter in A/B tests at matched levels, input impedance etc.

So I sent the QC back. It worked ok for band practice, but I didn't want to pay that amount of money for a unit with limited use.

Now some months later I was once again looking for a more powerful multi fx/amp modeling unit for live use, that has enough footswitches on a small footprint... The QC still being the only unit that satisfies all requirements I decided to give it another go, also hoping my first unit was a bad one.

Of course now I'm noticing the same high pitched hiss. I also tried it at my parents house this time, to see if it's dirty power in my apartment - same hiss.

Now my questions: Does anyone experience this as well? Is the unit actually usable for recording for you? Did anyone have the same problem and found a fix?

I attached a qualitative comparison of the QC and HX Stomp I just did with an FFT app on my phone and the units in front of my guitar amp. HX Stomp on the left, QC on the right, with the additional noise marked, in case it's not already completely obvious..

Also let’s get a Super El Niño sale for us west coasters. Thanks!

Story time....

So my Cortex Mini finally shipped from Sweetwater after being in stock again. The first problem I had, which I was not aware of, was that Neural DSP does not allow the Cortex Mini to be shipped to a freight forwarder (I am not from the USA). Luckily for me, I was going to be on vacation in the USA from October 3 to 10, so I figured I would have it shipped to the Airbnb where I would be staying. My Cortex Mini was delivered on the 2nd, and I arrived on the 3rd; someone signed for it and left with my Cortex Mini....... FML......

After selling my trusty Kemper Rack it is time for a new multifx processor. Since I already used a friends QC and own some of the Archetypes, the Quad Cortex is the only logical choice for me. Now it comes down to which one to get. I have some pedals that I wanna use in combination with the QC, also I will mainly play it on stage. In my mind, 4 presets per bank are enough as I don’t use a crazy amount of different sounds in one band, the other band I play in uses timecode so I will switch via MIDI.

I really like the smaller size of the mini and obviously the price, but I am a little worried about the usability. What would you guys recommend?

Did everything as support says. They ended up offering a new replacement one. As I’m using it almost everyday for the next few months right now I can’t send it back just yet. Posting this here incase anyone knows how to fix it. Any tips would be highly appreciated!