New Quad Cortex user here. I have been using Archetype Nolly X for awhile now with my Macbook and studio monitors. Loved it so much that I wanted to get a QC, a power amp, and a cabinet to have something separate from my computer.
When I run a signal chain in the QC with a cab sim and headphones, everything is fine. On my computer through my studio monitors, everything is fine.
When I run a high gain signal chain through the QC, out to a Seymour Duncan Powerstage 200, into a Mesa OS 4x12, I get some gnarly feedback, even when using noise gates. I’ve tried a bunch of different gates, even using multiples before and after the amp model.
It happens with multiple guitars; so it’s not the pickups. This totally could be user error, but something seems off to me. It’s like that traditional tube amp feedback happening. It’s not all the time, but if my playing isn’t perfect it’ll start to rise up.
Nothing is clipping and volumes are not out of control. Cables are good (they work properly without the power amp.)
Debating trying another power amp or buying a real tube head and running it off of the power amp there.
Any suggestions from people who have had this happen before? If it’s to be expected just let me know.
I would start with sharing your preset, then we could possibly determine where the issue is.
I use both an older ADA power amp with both a Marshall and 2x12 Mesa as well as Fender FRFR without issue. I assume when you run to your 4x12 that you are not using any cab/IR in the signal chain? Also, are you using OUT1/2 or 3/4? TRS or TS cables?
The profile I started with was “Woods” by iamtimhowley on the Cortex Cloud. As soon as I go to Scene B (lead tone without volume boost) it starts to get out of control.
No cab or IR signal. My output is 3. TS cable from my guitar to the QC, TRS from the QC to Powerstage.
Tried it real quick. I had similar issues with that specific preset when running to my FR10 and just tamed the output down on that EVH amp block which made it more manageable. IMO, the drive block with that EVH block has too much gain. But I also have my Global EQ set and configured for my specific setup which makes a large difference as well. Try lowering the gain on the drive and amp blocks and see if it cleans up enough to use. I also removed the drive block just to see how it sounded and it was better. Give that a try and see what you think or experiment with less gain on both drive/amp blocks.
The Powerstage input is TS, so I would change that cable to TS. Not saying that’s the cause here (it does sound like a “too much gain” issue), but sometimes using TRS can cause issues if either device doesn’t handle it properly.
I tried TS first, and then TRS. Wasn’t 100% sure if the QC out being recommended at TRS was an issue.
I also set the global output settings on 3/4 to -6db to compensate.
I totally get this can happen with the preset I posted. It’s also happening with other presets I’ve made and used for awhile now in Nolly X. Gain doesn’t seem to be that crazy to me.
Going to get some more feedback and then potentially try different global settings or a different power amp.
This can easily happen if you have too much gain on the amp block or a gain pedal. The feedback has to be coming from how the preset is setup or where you are in relation to the cab. This isn’t the power amp.
Just in case anyone comes across this thread and has the same issue; this was total user error. As soon as I moved the QC and got about 6 feet away from the cab, it greatly improved. So I just need to be mindful of gain settings if I need to be closer to the cab. I appreciate everyone’s help.
Makes sense! Especially for higher gain stuff. I only ever stand next to my cab/face it if I’m intentionally trying to get feedback. Same for most people live as well
The noise in the video sounds like pickup microphonics to me. Notice, at the end of the demo, as the guitar volume is turned down, the feedback goes away. If the squeal is affected by the guitar volume and where the guitar is, in relation to the cab (try facing away), it has to be coming from the guitar. Also, try switching your pickup selector to a different position or rolling back the tone and see if the amount and/or tone of the squeal changes. If so, it’s likely microphonic feedback. Even well-potted pickups can be subject to microphone feedback. With enough gain (or compression) and volume, any pickup can squeal. Very frustrating, I’m sure.
What I notice is that the impedance when plugged into the front of the interface can have a ridiculous amount of gain. When you use a direct box instead, you have more control and it seems to tame it.
