What causes amps to 'warble' on single notes?

[simon_d]

I didn't want to get all Jim Lill about it but I uploaded a clip, the tone is shitty and it will be an irritating experience, so be warned. JVM plays first, same note about 6 times. Listen out for the flutter underneath the note, a few rapid pulses. Is a bit like what you get with pickup string pull. On the other amp's clip the low fluttering is completely absent. Notes chosen as extreme examples for clarity. That flutter really gets under my skin for single notes. My balls don't seem to care.

https://streamable.com/8m9ruz

 

[scottosan]

Every time I turn on my tremoverb my balls grow exponentially bigger…then the sound waves from my speakers bounce off of them causing something similar to happen. Could this be the issue bro?

Dude. Just tape them back. It's 2023.

 

[JackBootedThug]

Dude. Just tape them back. It's 2023.

Truf….

 

[Devin]

I didn't want to get all Jim Lill about it but I uploaded a clip, the tone is shitty and it will be an irritating experience, so be warned. JVM plays first, same note about 6 times. Listen out for the flutter underneath the note, a few rapid pulses. Is a bit like what you get with pickup string pull. On the other amp's clip the low fluttering is completely absent. Notes chosen as extreme examples for clarity. That flutter really gets under my skin for single notes. My balls don't seem to care.

https://streamable.com/8m9ruz

I've heard this type of sound before but couldn't tell you what causes it


Are your strings new?

 

[simon_d]

I've heard this type of sound before but couldn't tell you what causes it


Are your strings new?

No, but it's the same strings on both clips. Same everything. Will need to remove the captor and recheck as splawndude suggested.

 

[Devin]

No, but it's the same strings on both clips. Same everything. Will need to remove the captor and recheck as splawndude suggested.

I'd try new strings as well in that case; old strings can have little divots form in them and cause some tonal weirdness

 

[simon_d]

I'd try new strings as well in that case; old strings can have little divots form in them and cause some tonal weirdness

Can't hurt to try it. It leaves the question why the one amp doesn't do it and the other does though.

Before getting this new amp I did just assume it was guitar rather than amp related. Some guitars have dead spots and warbles... 12th fret G string is always a tricky one.

 

[Devin]

Hmm I actually hear the warble in both clips, though it is much more pronounced in the first one

 

[simon_d]

Hmm I actually hear the warble in both clips, though it is much more pronounced in the first one

There's also the phasey volume drops throughout both, but I attribute that to normal distortion harmonics and cancellation effects.

Like you say it could be strings, but the one amp accentuates the effect while the other doesn't. Will find out soon.

 

[simon_d]

Right. Possible culprit found. Change of strings, and guitar. No difference. Warble is the same.

Take out the Captor.... less warble. Much less.

And the amp actually sounds a lot better anyway, which I am surprised by. The captor is really bright and shrill. I always thought it was really neutral, but I guess not.

The complication is that I have an 8 ohm Captor, but I recently changed speakers and the cab is now 16ohm. So I'm going out of the amp 8 ohm into Captor 8ohm, so that's matched, then into a 16ohm cab from the attenuated output... which may not be ideal, but not sure if causal. Without the captor its 16 ohm amp into 16 ohm cab)

 

[311boogieman]

Hope you found it then. I can't imagine that mismatch causing major issues but it is possible of course. I honestly couldn't hear much in your clip. Did you post 2 clips? Also, do you just have the 1 guitar?

 

[simon_d]

Hope you found it then. I can't imagine that mismatch causing major issues but it is possible of course. I honestly couldn't hear much in your clip. Did you post 2 clips? Also, do you just have the 1 guitar?

Interesting you couldn't hear it. Did you use headphones?

Only 1 clip. 1 guitar, 1 cab, 1 mic. Two amps.

It could be something electrical going on between the captor and JVM but most likely just a weird frequency causing the beating. Or something... ?‍

 

[311boogieman]

I see. So I ask again, do you have a second guitar you can try with? And no, but I can try with headphones later.

 

[simon_d]

I see. So I ask again, do you have a second guitar you can try with? And no, but I can try with headphones later.

Yeah, you'll need headphones to hear it.

I did use a 2nd guitar yes, with new strings too. That didn't help, only removing the captor did. Reverted to the first guitar, same result. Weird how the two amps react so different with it, the new amp didn't really care.

 

[simon_d]

Yeah, you'll need headphones to hear it.

I did use a 2nd guitar yes, with new strings too. That didn't help, only removing the captor did. Reverted to the first guitar, same result. Weird how the two amps react so different with it, the new amp didn't really care.

Well I since learned that the captor does not have a true speaker impedance curve but a U shape curve. This might explain some the problems I was having. Going to look at getting a better attenuator like a suhr or fryette.

 

[Jmcthe3rd]

In my experience this is more of a guitar pickup issue then an amp issue. Some amps can amplify it even more but, it sounds like ALL of your amps do this. This is why I feel like it's more of a guitar issue. I'm assuming your pickup has adjustable pole pieces. The pole pieces can be adjusted to give your individual strings more or less signal. Think of it like a microphone. Moving a pole piece closer to the string is like moving a mic closer to a speaker. You get a stronger signal. I would suggest moving the pole piece closer to the string in very small increments to see if the warbling gets better or worse then make more adjustments if necessary. If it gets better then keep moving it up until it seems like the same strength as the other strings around it. If it gets worse then move the pole piece down. There's something magical that happens to a guitar when you get ALL of the pole pieces set correctly. Each string will sound very strong, balanced against each other and sustaining. Then when you hit an open chord and all of the strings are in phase with each other it will just sustain and ring out for a for a LONG time. IMO then the guitar becomes ALIVE and the notes just jump off of the fretboard.

NOTE: You have to ensure the guitar is setup properly first. The nut is cut correctly (No buzzing on the first 5 frets) and the neck is fairly straight. (Slightly bowed is ok) The main thing is you don't have any buzzing of any notes anywhere on the neck. If you have any string buzz that will kill your sustain you won't be able to adjust the pickup pole pieces correctly until that is resolved.

 

[simon_d]

In my experience this is more of a guitar pickup issue then an amp issue. Some amps can amplify it even more but, it sounds like ALL of your amps do this.

Well, that's not quite correct. The JVM on OD1 is worst, the JCA100/20 do it but less. But the new amp barely does it at all with the captor. Taking the captor out solved the issue completely on all amps. And actually they sound better overall. Now, whether the amp+captor are just accentuating an issue in the guitar signal that's already present is another question. Since its no longer causing a problem, I'm happy with this solution, even if the neighbours aren't.