Quad Cortex signal is regularly distorted/corrupted

Quad Cortex Bug Reports
1

CorOS Version: reproduced in all versions between ~2.2.0 (factory install when I bought the QC) and 3.0.0

Describe your issue:
I bought the Quad Cortex from Thomann on November 2023, with the idea to play and record guitar while connected to my DAW, Ableton Live 11 Suite (build 11.3.25).

Since the first time I played it, I noticed that the signal would regularly sound distorted/corrupted for a couple seconds, and then go back to normal for a couple minutes. It actually sounds like a “redux” or “bit crusher” effect, I recorded and uploaded some examples here: https://on.soundcloud.com/ZhmoTvmed8ENfKTt5. I’m just a hobby musician, so I thought it could be some misconfiguration on my set-up, so I postponed looking into the issue for months. But lately this issue has started occurring more frequently, every ~5 minutes, and after lots of tweaking around I can’t figure out what’s wrong. Do you have any recommendation on what I could try?

Steps to reproduce your issue:

  1. Connect guitar to QC, connect QC to MacBook Pro (Intel) via USB and configure input in Ableton Live
  2. Play guitar for 3-7 min
  3. Signal starts to distort for 4-15 seconds

I have tried the following things:

  • Factory reset of the QC (also unlinking my account)
  • Plugging different inputs into the QC (bass guitar, synth), with different cables and input volumes (not clipping)
  • Using both Input 1 and Input 2
  • Using different OS on two laptops (macOS 13.6.7 with Intel, and Windows 11)
  • Adjusting buffer size between 64 and 512 samples
  • Dry/wet signals on different USB outs (both signals are affected by the issue)
1 Like
2

Have you set your project to 48k in your DAW? :face_with_monocle:

3

Yes, Ableton actually locks the project rate to 48k as soon as I select the QC as input. Good thing to check anyway :+1:

4

The other thing that people trip on is, you must avoid USB hubs, no front panel etc, just the sockets that go directly to the motherboard. If it’s not happening in the QC on its own, just in your DAW then it’s most probably the USB bus itself or some setting in Ableton, I don’t use that one myself, have you been able to replicate the symptoms in other DAW’s?

2 Likes
5

Not much to try really. I think it’s an issue with their drivers

6

Spot on! After connecting directly the QC with my Windows laptop I haven’t been able to reproduce the issue again. I’ll find a USB-B to USB-C cable and see if it also works for my MacBook, but for now I’m just so glad to discard the thought of having a defective QC. Thanks so much for that tip :slight_smile:

2 Likes