Need help with using external pedals & tone suck with Quad Cortex

Hi Quad Cortex users and sound geeks all over the world

Just got my QC earlier this week. I love it but i’ve had some of the following issues :

I still have my pedalboard and would like to keep it for now.

My pedalboard chain is : Walrus Deep6 Compressor > EQD Plumes > EQD Westwood > Big Muff Pi > Small Clone > EHX Ocean 11 > Boss RV6 > Holygrail
I know, i have too much reverbs and i will sell those if i can solve my QC problems.


I have a “tone suck” matter. When i plug the guitar directly into QC, the sound is bright and feels natural.
When i plug the pedalboard after the guitar, into the QC, i experience tonesuck. Guitar sounds muddy and highs are kinda scooped. (or any isolated pedal, even if they are true bypass)

I tried to plug the pedalboard into FX Loop 1 or 2 and it was worse, since i have lots of noise, in addition of the tone suck. It put the FX loop at the begining of the grid, just after the noisegate, or even without anything before.

I’ve read a lot of things, and apparently, tone suck can be fixed by using a buffering pedal at the beginning of the chain, which i will try soon.

Still, the FX loop seems to get a lot of noise because of the ungrounded adapter etc. Also, it seems to me that the FX loop colors the sound.

I’ve tried every pedals of mine, one by one, and experienced the “tone suck” scooping high and stuff with each and every one of them. I never noticed this scooping within the amp (AC10C1)…
i’ve tried those before the input, and within FX loop 1 & 2

My questions are :

  • If i use the pedalboard into a FX Loop, is it useful to put a buffer pedal ,anyway, at the begining of the pedalboard chain, and will it solves impedance problems? Or do i have to use it after the guitar and before the input in the QC ? Or is it useless ?

  • Would a DI Box somehow be useful to “clean” the signal after the pedals, in the FX loop or before the input ?

  • Any other idea to solve this matter ?

Thanks in advance to everyone who will be brave enough to read all of this, and to any held that could be provided. :pray:

Cheers from France. :fr:


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hi @Jib2a and welcome to the community! The ungrounded power would have zero to do with noise within your pedalboard. That noise, if you actually experience it etc., might be evident when using only headphones but you have other things plugged in to the QC if you are using the loop etc., so definitely something with how you are using the loop, cables are splitters/mixers you are using. Something within your pedal board is ‘sucking tone’ as you say, I would recommend to place time based effects into the loop and drives/boosts etc., at the front of the amp block. If you have it setup that way, I would look at each FX in the loop separately until you can determine which FX is impacting your tone. You can email and they might be able to help but that is my recommendations. Good luck!

1 Like