I get feedback when I stop playing on some of my rhythm patches???

mr_fender said:
It looks like you're pushing the circuit into oscillation. Any amplifier will go into oscillation if the input and gain are high enough. You are taking a very high gain amp and pushing a really hot signal into it with the drive block. Some amps are more prone to it than others. You also have the Drive block high cut set all the way up to 20kHz. Big boosts in the highs will make oscillation worse. Pull the high cut back down to control the gain in those upper frequencies. It's not a bad sounding preset, but I would dial the gain back and turn down the level in the drive block. You'll get a tighter, less noisy tone and it will be far less likely to oscillate on you.
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To be clear, I'm boosting the entire frequency range. I'm not "boosting the high". I don't like to narrow the frequency range of my expensive awesome pickups so I always leave the high pass and low pass at "non-existent" on drive blocks, and I'm not going to change that.

I'll try your level suggestion but this really is the best I could get things to sound except for the squealing. Maybe I like the sound of "noisy" patches. I also want to reiterate that this problem didn't exist on the Axe-Fx Ultra with similar settings. Whatever is causing it is a downgrade in *something*. Of course there are numerous upgrades in the 2 but this part is a downgrade.

Since the squealing can be fixed with the ouput1 knob alone, I don't see how this isn't a software bug. The amp block and all other blocks can stay constant in their processing and just the final output value causes it. Whether it happens on real amps or not doesn't really matter.

And why does using active pickups or active electronics circumvent the problem? Does anyone have an explanation? The signal is still just as driven and even hotter with the actives.
 
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I believe actives are a very low impedance load on the input. My uneducated opinion is it probably has something to do with tuning the oscillation frequency outside of the audible range.
 
jerotas said:
...why does using active pickups circumvent the problem? Does anyone have an explanation? The signal is still just as driven and even hotter with the actives.
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That's a good question.

What's the difference between passive and active pickups? Actives have lower impedance and better immunity to interference.

Lower impedance will shift the pickup's resonant peak a bit, and let more highs pass through. The shifted resonant peak might make a difference; if anything, letting more highs pass would make the active more prone to feedback, not less prone. So that's probably not it.

But the added immunity to interference...that could make a difference. If your passive pickups are picking up more RF junk, that could create enough signal to trigger feedback in a high-gain situation. If that's the case, you should be able to kill the feedback by raising the threshold on your noise gate. You might have to raise it crazy high, but it would be a test that could eliminate some culprits.

And if that interference is being rectified—by, say, a bad solder joint in a cable—that would only make things worse.

Which brings up an interesting question: have you tried a different guitar cable?
 
Rex said:
That's a good question.

What's the difference between passive and active pickups? Actives have lower impedance and better immunity to interference.

Lower impedance will shift the pickup's resonant peak a bit, and let more highs pass through. The shifted resonant peak might make a difference; if anything, letting more highs pass would make the active more prone to feedback, not less prone. So that's probably not it.

But the added immunity to interference...that could make a difference. If your passive pickups are picking up more RF junk, that could create enough signal to trigger feedback in a high-gain situation. If that's the case, you should be able to kill the feedback by raising the threshold on your noise gate. You might have to raise it crazy high, but it would be a test that could eliminate some culprits.

And if that interference is being rectified—by, say, a bad solder joint in a cable—that would only make things worse.

Which brings up an interesting question: have you tried a different guitar cable?
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Yes I tried another cable. 2 others. I don't know why you're asking this though, because 3 out of 3 other people that tried my patch reproduced my problem exactly. It's not MY problem, it's a problem with the Axe-Fx in one way or another. Everyone can reproduce it if they want to with passive pickups.

Raising the noise gate super high, what that does is you hear a split second of squealing when you stop playing and then it's cut off. Sounds ridiculous.
 
Rex said:
Just digging for possible solutions.
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I know man. Thanks for thinking about it.

This *is* an actual problem with all units (post Ultra) that I've found. I've eliminated all variables. Whether anything will be done to address it is yet to be seen.
 
I don't think it's necessarily a software bug. The output knobs are not affected by the software. They are in the analog path after the digital to analog conversion. I think it's probably a combination of factors. The high gain and high output settings may be causing a physical coupling internally between the input and output. Setting the output knobs to max allows for unity gain through the Axe with no gain on the grid (all shunts or bypass mode). The amp and drive blocks can provide large amounts of gain so the output knobs may need to be reduced to avoid internal coupling and feedback when things on the grid are cranked up a lot with certain amps. You might just have to find the right compromise for certain settings.
 
Yeah I found switching the input impedance from default (1M) to 1M CAP (or another impedance) helps a bit, with of coarse lower the output knob too!
Other options to help tame any squealing would be to lower gain or cut some high frequencies before the Amp Block.
Can't wait to see if my new guitar helps with my squealy probs! Time will tell.
Current pickups I'm using are Lundgren M8's. Sort of medium output pickups so I tend to need abit of gain. Going to switch to Seymour Duncan Nazgul & Sentient pickups so it might let me turn the gain down abit so.....yeah!
 
mr_fender said:
I don't think it's necessarily a software bug. The output knobs are not affected by the software. They are in the analog path after the digital to analog conversion. I think it's probably a combination of factors. The high gain and high output settings may be causing a physical coupling internally between the input and output. Setting the output knobs to max allows for unity gain through the Axe with no gain on the grid (all shunts or bypass mode). The amp and drive blocks can provide large amounts of gain so the output knobs may need to be reduced to avoid internal coupling and feedback when things on the grid are cranked up a lot with certain amps. You might just have to find the right compromise for certain settings.
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Yeah good point, it could be a "hardware bug" haha.
 
jerotas said:
Raising the noise gate super high, what that does is you hear a split second of squealing when you stop playing and then it's cut off. Sounds ridiculous.
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Have you tried adjusting the attack/release/hold on the gate block? I've noticed this same behavior on quite a few of my custom patches before. My standard starting point for a high gain patch gate block is:

attack=1ms
release=20ms
hold=40-50ms

Of course these vary from patch to patch. And yes, if you bump the gate ratio up higher by itself it will begin to affect the tone negatively. With those settings and a ratio set between 2.5-4 you can clean up a ton of the squeal/unwanted feedback on the high gain stuff.

(Sorry if this was already mentioned - I didn't read the whole thread in it's entirety)
 
Etudica said:
Have you tried adjusting the attack/release/hold on the gate block? I've noticed this same behavior on quite a few of my custom patches before. My standard starting point for a high gain patch gate block is:

attack=1ms
release=20ms
hold=40-50ms

Of course these vary from patch to patch. And yes, if you bump the gate ratio up higher by itself it will begin to affect the tone negatively. With those settings and a ratio set between 2.5-4 you can clean up a ton of the squeal/unwanted feedback on the high gain stuff.

(Sorry if this was already mentioned - I didn't read the whole thread in it's entirety)
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I adjusted attack, threshold etc. Didn't get it to working without hearing a really fast instant of squeal.
 
Just thought of one more thing to try. Plugged into the rear input instead with the same settings. NO SQUEAL!!

So my conclusion is that this is a software bug or side effect having to do with the "special sauce" on the front input.
 
jerotas said:
Just thought of one more thing to try. Plugged into the rear input instead with the same settings. NO SQUEAL!!

So my conclusion is that this is a software bug or side effect having to do with the "special sauce" on the front input.
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Or maybe the extra wiring that extends to the front panel.
 
jerotas said:
Of course, or I get no sound at all. Turned the speaker on for the test since I've never used rear input on the 2XL before.
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juuuuust checking :)

well that is a great "tangible" piece of information to find - front input vs rear. awesome.
 
Rex said:
Or maybe the extra wiring that extends to the front panel.
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I think you said something about unity gain maybe causing it (hardware not software). But the thing is I don't really have to have output 1 on 100%. It can be anywhere from ~55 - 100% and the squealing still happens the same. Yet the volume does get louder as I turn it from 55 to 100. So I think the unity gain theory isn't the problem.
 
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