As you can see from my picture below, and my fancy drawing, I’ve placed my FX Loop where the red circle is, so everything after that would go through the loop.
When I tried adding a high gain amp head, or a capture of my personal amp head (with no cab/IR) AFTER the loop, I was getting a HORRIBLE squeal and high pitched chimey/ringing thing going on (more on that below), like there were several preamps going into each other. But if I DISABLED the FX loop block, it sounded GREAT with QC amp head block engaged. But when I turned that amp block off (FX loop still off too), my clean tone was horrible and dead and sounded nothing like the amp I’m plugged into, until I activated the FX loop again.
**When I’d unplug JUST the cable from the QC to the amp input and strum my guitar, leaving all the other cables connected, I didn’t hear my guitar, but I heard that high pitched squeal/ringing sound.
I’m 100% sure I had the cables ran correctly, I’ve been using the 4CM for several years now on other units and can hook it up in my sleep (plus, I double and triple checked it against the QC manual… I even tried different cables).
What I ended up having to do is add the FX Loop block to the same footswitch I’m using to turn on the high gain amp block, but the FX loop is set to turn off when I press it.
I’m sure there’s something weird with my routing, but I’m just not sure what it is?
****Do I maybe need to change the “multi out” at the end to just “output 3”? Is the “multi out” sending the signal through the loop more than once, or somehow overloading it??
-ground loop. use the I/O menu to adjust that. I’ve had this happen when making captures of amps.
-the fx loop boosts the signal of the signal by about 4.5 DB, so you’re actually pushing the amp even more when that’s engaged
Also looks like you have “multi out” selected for the row 3 output. Definitely wouldn’t suggest that. Try selecting the proper specific output you’re using for that instead of “multi out”
That is, in fact, what was happening. If your physical amp’s preamp is in the QC’s fx loop, then you were running the physical (pre)amp into the high-gain amp model, which came after the loop. Add to that the 4-5dB gain boost from the fx loop and depending on your settings and other gear you may get into “horrible feedback” territory.
And this is, in fact, how you should do it (or using scenes to de/activate the fx loop and amp model). If you want to alternate between your physical amp’s preamp and the high gain amp model that is. You will also see Rabea do this in the Youtube videos linked by @SelfTitledLP
The setup suggested by @DiffractionCircuit is nice and more straightforward, but won’t work if you want to switch between the physical preamp and an amp model.
True… OP gave a lot of detail about cable and FX loop setup but didn’t describe the intended end use very well.
@telejas, what are you trying to accomplish with this QC / tube amp setup? Are you trying to make it so that you can switch between the tube amp’s preamp and the QC’s amp blocks/capture blocks (being fed into the power amp via the FX loop)?
The amp is a Dr. Z X-RAY, which is the absolutely best clean sounding amp I have ever played in my entire life. I’ve got captures of it on my QC that I use all the time, which are very very close, but don’t 100% capture the feel And tone… while it’s close enough, and nobody can tell a difference besides me… I still want the option of using the actual amp along with all the effects and distortion tones from the QC.
I’m playing a very large show in a couple months that I’ve played before, and I know the stage volume is extremely loud and I have had trouble hearing myself before. I would like to use my actual amp sitting behind me, but I’d like to use the actual clean channel of the amp itself.
