Load box started squealing last night

[DrewJD82]

Last night I took a break from playing my Plexi50 to throw some food down my thoat, I left everything on as I planned on returning to the studio, maybe 20 minutes later I thought there was a fire alarm going off outside my apartment but quickly realized it was coming from my studio. Once I was in there I realized it was coming from either the Plexi50 or the Suhr RL on top of it, so I shut the Plexi off and the sound stopped immediately.

I waited a couple minutes and turned it on again, seems when the fan starts up that squealing sound ramps up as well. It doesn’t sound like a physical grinding or bearing issue, it sounds like an electronic ringing. I need to shoot Suhr an email but was wondering if anyone else ran into something similar with a load box?

 

[GreatGreen]

Have you eliminated your other variables? You need to figure out whether it’s the load box or the amp. What happens when you plug another amp into it?

 

[DrewJD82]

Have you eliminated your other variables? You need to figure out whether it’s the load box or the amp. What happens when you plug another amp into it?

I wasn’t exactly feeling adventurous last night and just shut it all down. The sound is 100% coming from the Suhr RL and is definitely related to the fan as you can hear the fan kick on the second the squealing starts. I’ll try plugging another amp into it when I get home.

 

[EOengineer]

When things are squealing are you still getting a healthy signal passing through the RL?

My anxiety would have me plugging the amp into a cab just for peace of mind that the amp’s ok, but I agree with your assessment that it sounds mechanical and contained to the RL.

Everything breaks eventually, but I bet Suhr takes care of you.

 

[spawnofthesith]

I was having some issues awhile back with my captor squealing like crazy and the fan going into over time. Iirc it seemed to have to do with where I had the box positioned in relation to amp/speaker/guitar. However, I have not had a single issue with that since rearranging my room and that was over a year ago

 

[DrewJD82]

When things are squealing are you still getting a healthy signal passing through the RL?

My anxiety would have me plugging the amp into a cab just for peace of mind that the amp’s ok, but I agree with your assessment that it sounds mechanical and contained to the RL.

Everything breaks eventually, but I bet Suhr takes care of you.

I didn’t even try playing through it, once I realized it was coming from the direction of the amp and load box I just shut it down. Should also note, it wasn’t even warm to the touch when I put my hand on it. I know the Suhr RL’s fan kicks in once it’s getting 25 watts, I had the Hot Mod in the Plexi50 and the volume on 4 on the normal channel. Already shot Suhr’s CS an email and got verification they received it. Fingers crossed it’s a “Oh, this happens from time to time, shoot us a few bucks and we’ll send a new fan your way” or something!

I was having some issues awhile back with my captor squealing like crazy and the fan going into over time. Iirc it seemed to have to do with where I had the box positioned in relation to amp/speaker/guitar. However, I have not had a single issue with that since rearranging my room and that was over a year ago

Hmm, I remember the fan ramping up pretty damn loud, louder than I’d heard it before. I wonder if this is the same issue. I’ve had it sitting on top of the head since I got the head, but I’ll try moving it when I get home today.

Hahahhaha and the last two nights I’ve been having this fucking romance with this amp after figuring out the 4 dirt pedals I’m going to keep in front of it. I’m smitten with it, I want to go home and play it now!!

 

[spawnofthesith]

Thread I posted here when I was having squealing issues: https://thegearforum.com/threads/multiple-conundrums-any-sleuths-captors-irs-etc.6038/


Most of the discussion in the thread is about IRs, the only relevant stuff is op and first response lol

 

[MirrorProfiles]

load boxes causing squealing is pretty normal, these videos will help:

 

[GreatGreen]

I wasn’t exactly feeling adventurous last night and just shut it all down. The sound is 100% coming from the Suhr RL and is definitely related to the fan as you can hear the fan kick on the second the squealing starts. I’ll try plugging another amp into it when I get home.

The sound could be coming from the RL, but that doesn't necessarily mean there's anything wrong with the RL.

It could mean the amp is oscillating and the RL is correctly and healthily reproducing the unhealthy oscillation coming from the amp. I also have a Plexi and can tell you that at extreme settings, it will oscillate like crazy, which you can absolutely hear coming through the RL.

You might assume the noise is related to the fan but it could be that the fan and the LED both happen to be engaging specifically because of oscillation happening in the amp.

 

[DrewJD82]

The sound could be coming from the RL, but that doesn't necessarily mean there's anything wrong with the RL.

It could mean the amp is oscillating and the RL is correctly and healthily reproducing the unhealthy oscillation the amp is producing. I also have a Plexi and can tell you that at extreme settings, it will oscillate like crazy, which you can absolutely hear coming through the RL.

You might assume the noise is related to the fan but it could be that the fan and the LED are both engaging specifically because of the amp's oscillation.

What would cause the amp to oscillate? I have the Hot Mod in there but I’m not running the head all that hard, it’s on 4 on the Normal channel, non-jumped.

 

[Ed DeGenaro]

Ground loop

 

[Jarick]

Bad inductor possibly? Wires getting loose could potentially cause ringing?

 

[GreatGreen]

What would cause the amp to oscillate? I have the Hot Mod in there but I’m not running the head all that hard, it’s on 4 on the Normal channel, non-jumped.

There doesn't necessarily have to be anything wrong with the amp for it to oscillate. It could just be the design. My plexi has a post phase inverter master volume and when I crank it to 10, along with Volume 1 and also the Treble and Mid knob, totally opening all three pots, the amp will oscillate like that under the right circumstances.

Guitar amps are pretty extreme but also primitive contraptions. Sometimes there's simply enough internal volume/power going through them that the signals get too strong and bleed through to other parts of the circuit earlier in the chain, which then loop back to the later parts of the chain for even further amplification and loopback and you get immediate signal buildup that goes as loud as the components can physically produce, usually presenting in a very high pitch whine, sometimes so high you can't directly hear it, even while a reactive load box is whirring like crazy because of it.

I'm not sure how the Hot Mod would impact the circuit though. It could cause oscillation but I have no personal experience with those devices to say for sure. That's why I recommend you test the RL with another amp as well.

 

[DrewJD82]

There doesn't necessarily have to be anything wrong with the amp for it to oscillate. It could just be the design. My plexi has a post phase inverter master volume and when I crank it to 10, along with Volume 1 and also the Treble and Mid knob, totally opening all three pots, the amp will oscillate like that under the right circumstances.

Guitar amps are pretty extreme but also primitive contraptions. Sometimes there's simply enough internal volume/power going through them that the signals get too strong and bleed through to other parts of the circuit earlier in the chain, which then loop back to the later parts of the chain for even further amplification and loopback and you get immediate signal buildup that goes as loud as the components can physically produce, usually presenting in a very high pitch whine, sometimes so high you can't directly hear it, even while a reactive load box is whirring like crazy because of it.

I'm not sure how the Hot Mod would impact the circuit though. It could cause oscillation but I have no personal experience with those devices to say for sure. That's why I recommend you test the RL with another amp as well.

Ahhh, yeah, I’ve had it squeal at me when I’ve cranked both Volumes, but there’s nothing dimed on it at all right now, at most the Treble is at 3 o’clock with everything else below 12 o’clock. Bass volume is off.

I think the biggest concern is that nothing has changed with that setup for over a week, same pedals, almost the same settings on the amp, same pedal order I’ve had for a few days.

I’ll turn it all on tonight and see if I can sort anything out. The ground loop theory is certainly possible as everything is getting power from the same outlet, just odd that it’d pop up out of nowhere after this amount of time.

 

[GreatGreen]

Ahhh, yeah, I’ve had it squeal at me when I’ve cranked both Volumes, but there’s nothing dimed on it at all right now, at most the Treble is at 3 o’clock with everything else below 12 o’clock. Bass volume is off.

I think the biggest concern is that nothing has changed with that setup for over a week, same pedals, almost the same settings on the amp, same pedal order I’ve had for a few days.

I’ll turn it all on tonight and see if I can sort anything out. The ground loop theory is certainly possible as everything is getting power from the same outlet, just odd that it’d pop up out of nowhere after this amount of time.

Ok gotcha. If nothing about the setup has changed at all in the last few weeks and you're getting a brand new type of noise, that could definitely suggest something new is going on, absolutely. Really I'm just trying to help avoid spinning your wheels chasing down a red herring when the real problem could be elsewhere, that an issue presenting in one place (like in a reactive load) might not necessarily mean the whole issue starts and ends in the reactive load.

It definitely could be the reactive load, but as of yet, it doesn't sound like the problem has been definitively narrowed down to just that component.

 

[Chocol8]

If the fan on the Suhr is coming on high, I think it likely means that there is a strong signal coming from the amp to the Suhr. The amp feeding back or oscillating could definitely be a cause, and anything that adds gain or room for interferences like the hot mod could be contributing.

Oscillation is a finicky thing that can be caused or cured by such seemingly inconsequential things as small changes in wire routing in the amp (lead dress) and may have happened last night due to some combination of temperatures, outside interference, placement of the amp and load, and maybe guitar or cables etc.

 

[DrewJD82]

Thanks gents!!!

I’m just going to go direct into the amp from the guitar and see what variables I can knock out while waiting for Suhr to respond.

 

[Orvillain]

I get this when I have the Axe3 connected to my Mark V, and then connected to my Suhr Reload. If I connect to a cab, it doesn't happen.

A 1:1 isolator cures it.

 

[DrewJD82]

I get this when I have the Axe3 connected to my Mark V, and then connected to my Suhr Reload. If I connect to a cab, it doesn't happen.

A 1:1 isolator cures it.

Does it happen immediately, or it kicks in after a while?

Suhr thinks it’s a ground loop and essentially told me to make a Humbuster cable for it, which I can give a shot when I get home. I probably said it in this thread already, but my concern is that nothing has changed for weeks with the setup, it’s been fired up daily for 3-4 hours without a single issue, though I did leave the amp turned on for quite a while a couple times without playing through it, like 5-6 hours a couple different times.

I was playing for about an hour before I stopped to eat, then 20 mins or so went by when it started up.

 

[Orvillain]

Happens immediately for me.