Marshall MG30CFX annoying whistle/bell/ring sound behind strums

eSGEe said:
also the combo of neck and middle --- or middle and bridge pickups on your Squire SHOULD be "hum canceling" to a point -- try using 2 pickups not just the neck that may bring some hum down as well. ;)
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This is true and I have this effect. Usually there's still some feedback unless I crank the guitar's own volume to 10 though. This "hum cancelling" set up of the Squier works on mine, provided guitar volume is at 100% (the "volume" knob in the guitar at position 10).

My old Jennifer probably has good shielding, I use to play it at, like, 10%-50% volume (so I can switch from strums to fingered, solos without moving to the amp), and hum was never a problem like it is with the Squier (but that's not the problem I am trying to troubleshoot in the video from initial post).

p.s.: I'm sorry I'm triple posting, I hope it's no problem. I usually quote the replies in a single message but these were so far away that I only realized later.
p.p.s.: thanks for all the feedback!
 
For a reference, the whistle I'm complaining about sounds more or less like this "cheap whistle" in the following video. It "whistles" as like an "harmonics" during the strums (not when the guitar is idle).

The embedded video below points to the exact moment the whistle is played I'm just referencing to that "cheap whistle (unbranded)", so, just the first whistle that plays at 0:47 of the video.


(...and I am quad-posting)
 
avenger said:
Sorry guys, I failed miserably in showing the issue I am having it seems. I got quite a busy weekend and I will try to find some time to edit a bit of the initial video in a good vid editor and "equalize out" to leave just the annoying whistle. I am kind of inclined to believe the weak solders in the amp may be intensifying that annoying whistle. Unfortunately getting the amp warm didn't change the behavior of the whistle; this weighs against being weak solder joints (but does not rule them out!).

My second suspicion (which is still a "little" unbelievable) is just that the amp is letting go (by design) some high frequencies people usually don't perceive and I am crazy enough to have a superhuman kind of eardrums to catch those up. See? Quite unbelievable sort of thing. That's crazy, I don't even know why I'm suspecting this, ok? :)

I must rule out these:
- Hum/feedback: the beebox can get plenty of that, and I am kind of waiting the guitar warranty to be gone before I rip it open to shield. My old jennifer has a lot less hum. Both my guitars are single coil, noise pickup-driven. I can change this kind of noise by taking the amp far/close to the amp, by just turning around 90 degrees or so (power lines induction is pretty strong and I'm at the 4th floor, just close to one), and some neighbor taking a bath in electric heated shower, or using the microwave.
- Springs: I would hear them by strumming the guitar hard while unplugged, this Squier is dead silent in that regard (that's what I concluded from the the vid on the les pauls' provided first)

I am pretty inclined to say the annoying whistle lies in highs. But I might just get surprised with how "low" that is. So I must submit the recorded audio to an equalizer.
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The last source of this type problem: is a microphonic preamp tube.
The tube that is usually microphonic is the one closest to the input jack.

Buy 1 new 12AX7 tube, swap out the preamp tubes one at a time,
retest the amp each time you swap one out.
If there is a microphonic tube, you will find it.

TEST: turn the amp on,
turn the guitar volume to zero.
Turn up the amp volume and master volume.
TAP on the tubes one at a time, and if there is a microphonic tube you will find which one it is.

It is not unusual to have a tube which is microphonic. This is a common problem.


Note:
you don't need to buy a whole set of tubes.
Just buy one 12AX7 to swap out the old tubes....
 
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Amp Mad Scientist said:
The last source of this type problem: is a microphonic preamp tube.
The tube that is usually microphonic is the one closest to the input jack.

Buy 1 new 12AX7 tube, swap out the preamp tubes one at a time,
retest the amp each time you swap one out.
If there is a microphonic tube, you will find it.

TEST: turn the amp on,
turn the guitar volume to zero.
Turn up the amp volume and master volume.
TAP on the tubes one at a time, and if there is a microphonic tube you will find which one it is.

It is not unusual to have a tube which is microphonic. This is a common problem.


Note:
you don't need to buy a whole set of tubes.
Just buy one 12AX7 to swap out the old tubes....
Click to expand...

Good to know that one for my upcoming Origin20c! :D Thanks!


67plexi said:

Elektrotanya for electronics experts

Electronics forum for electronics experts to repair defective appliance.
elektrotanya.com

A service manual download it's solid state
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WWWWWWWWWWEEEEEEEEEEEEEEEEEEEE!!! :dancepoo: That's a few models behind but I bet the juice is all there! (I believe the DFX still didn't have the "octave" effect. But that should be close enough! Thanks a lot!
 
avenger said:
I must rule out these:
- Hum/feedback: (...)
- Springs: I would hear them by strumming the guitar hard while unplugged, this Squier is dead silent in that regard (that's what I concluded from the the vid on the les pauls' provided first)
Click to expand...

I shamefully regret "ruling out" the springs!!! This must be it. I can now hear the whistle in the bee box. Or am I so obsessed with that whistle that now I hear it everywhere. I will definitively take a look at the springs! I just need to gather courage to open the guitar's backplate and void its warranty... :S

edit: I still couldn't hear the springs whistle while unplugged but I guess this is just because the amp is "amplifying" the feedback. I can get a slight interference in the whistle if i place my hand firmly in the bridge when it screams. The thing is that, as the guitar is new, it is just developing this whistle; so it has gotten worse (as I refuse to stop playing the guitar!)
 
avenger said:
I shamefully regret "ruling out" the springs!!! This must be it. I can now hear the whistle in the bee box. Or am I so obsessed with that whistle that now I hear it everywhere. I will definitively take a look at the springs! I just need to gather courage to open the guitar's backplate and void its warranty... :S
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Opening the back plate will not void the instruments warranty, in this you are safe.
Cheers
Mitch
 
I'm not afraid of opening the guitar nor the amp. Wanna take a look at my bee box?

If you look at bottom righ-ish, where a red wire connects to a resistor, you'll notice how black it is. It got a tan when another resistor (right below the transistor to the right) literally lit up when it broke 10+ years ago.

This thing looks simple, the speaker is meh, but the thing really is loud. It is "rated" 35W, but it really does sound louder than the MG30CFX! Not just the 5-10% (or less) difference of perceivable sound volume people talk about! It is just much wilder, hard to tame the highs/lows so the speaker doesn't clip. I can never turn that one to the max. It also gives the feeling it can't work 10 minutes straight at 90% volume or more.

Not to mention the fixes & mends I made to my 70's Jennifer Magnos strat. The thing is not to void the warranty. And I mean to be honest with that. So, just to be safe, I contacted the shop I purchased the guitar from.

IMG_20200703_202830703.jpg
 
I finally edited that original video; just extracted the first "chime sample" and replayed it by trying to equalize "up" the chime to emphasize it. Seems it is poisoning across the audio spectrum and I couldn't manage to "filter the chime out". It is there in frequencies as low as 200Hz and as high as 4kHz.

Here's the video I put together with DaVinci Resolve:


Thanks for all who helped. I am really inclined to believe this is due to the not-so-fancy springs in the back of the guitar.
 
avenger said:
I finally edited that original video; just extracted the first "chime sample" and replayed it by trying to equalize "up" the chime to emphasize it. Seems it is poisoning across the audio spectrum and I couldn't manage to "filter the chime out". It is there in frequencies as low as 200Hz and as high as 4kHz.

Here's the video I put together with DaVinci Resolve:


Thanks for all who helped. I am really inclined to believe this is due to the not-so-fancy springs in the back of the guitar.
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You Tube has multiple strat set up techniques to eliminate this chime buzzing. Have you googled any of them ?
 
Mitch Pearrow SJMP said:
You Tube has multiple strat set up techniques to eliminate this chime buzzing. Have you googled any of them ?
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I have seen the vids shared by @Amp Mad Scientist and will look up a few more to see if there's something else easier for me to do (the heat blown rubber is not a solution to me, and I feel the adhesive tape might be the way to go, but may make things sticky (its glue) over time, or require further maintenance as it ages. Thinking of a muffling pad to keep contact with the springs but it may also age quickly... anyway I will only be able to work on that Saturday (and I will try to "tape" that in a video).

I got clearance from the retailers to pry open the back plate. :D
 
avenger said:
I have seen the vids shared by @Amp Mad Scientist and will look up a few more to see if there's something else easier for me to do (the heat blown rubber is not a solution to me, and I feel the adhesive tape might be the way to go, but may make things sticky (its glue) over time, or require further maintenance as it ages. Thinking of a muffling pad to keep contact with the springs but it may also age quickly... anyway I will only be able to work on that Saturday (and I will try to "tape" that in a video).

I got clearance from the retailers to pry open the back plate. :D
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Just stuff a piece of cloth inside.
Or foam...anything that stops the springs from vibrating.
 
Amp Mad Scientist said:
Just stuff a piece of cloth inside.
Or foam...anything that stops the springs from vibrating.
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:cry:

I did this, had some cloth to stuff in. Also tried to tape it down... and the thing is still there, not the slightest change.

I am now suspecting the strings. I'm in the verge of swapping the strings (which are less than three months old of light play). It comes with some .09 strings, I think nickel-wound, and I got myself an Ernie Ball's .08. Ummm.. "Extra Slinky", not sure their composition now. Am I barking at the wrong tree here? Or maybe, I developed some illness that makes me sensitive to the sound of strings. Wow that would be worst case, can't swap my ears or brain! :(
 
avenger said:
:cry:

I did this, had some cloth to stuff in. Also tried to tape it down... and the thing is still there, not the slightest change.

I am now suspecting the strings. I'm in the verge of swapping the strings (which are less than three months old of light play). It comes with some .09 strings, I think nickel-wound, and I got myself an Ernie Ball's .08. Ummm.. "Extra Slinky", not sure their composition now. Am I barking at the wrong tree here? Or maybe, I developed some illness that makes me sensitive to the sound of strings. Wow that would be worst case, can't swap my ears or brain! :(
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That’s funny, maybe you are picking up something nobody else can hear ??
 
I don't think so. Maybe everyone hears it. I can see in the equalizer the chime comes in various frequency range segments between 200 to 5000Hz.

The good thing is that my brand new Origin20c has arrived and its presence + tilt knobs allows me to tame away the chime to content without losing the "punch" of the open tone knobs! I didn't swap strings at all. I believe it is just the pick ups are too bright for the MG, and even the bee box is catching them now.

When untamed, the chime is very annoying in the Squier Affinity, but if I am specifically looking for it, I can find it in the bee box, in Origin20c and even in my "darker" 70's Jennifer Magnos strat.
 
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