egnater rebel 30 - mechanical/electrical noise?

[rrosa]

hi,

i've a got 2 rebel 30, a head+cab and a combo.
i've tried the combinations of head+cab, combo, combo+cab, head+cabFromTheCombo.
both with and without reverb, on both clean and dist channel.
i've also tried several guitars, just in case.
all combinations display the issue.

i've noticed a noise, like some more high than low tone vibration. i cannot hear it at extremely low volume, like barely on, but it becomes clear at over 1/8 of vol. it does not grow in intensity as i crank the volume.
i thought i was hearing it while playing, and i managed to narrow down a way to trigger the noise.
i think it's something that resonates when i play a specific note. i've tried a slightly sharp C and it triggers the noise.
sample audio clip attached.
first you'll hear a C, then a slight bend, and then the noise will add onto the clean tone.

it's not an issue in the sound circuit, since the noise will not be present if i record using the rec output, even though i hear it while playing what i record.

does this happen to anybody?
i've emailed egnater support about this.

thanks.
salú

 

[rrosa]

problem solved.

i tested a brand new 15w tweaker at guitar center and also noticed the noise. showed it to the guy there, in case it was one of the many things about tube amps that everybody knows except me, but it was not the case. he agreed with me that it must be some manufacturer issue.
it's not something specific to one tone, this is just a way to trigger it and be able to hear it. after you've detected the noise, you'll hear it while almost all the time while your playing. it's like the little piano thing in "why don't you get a job" (offspring once you've noticed it's there, you'll hear only that and deeply hate it.

i've tried 3 different amps, 3 different models, all brand new, and i've heard it on all of them. i can't be *that* unlucky.

i was about to return it when i started looking up more stuff online and everyone was fascinated by their egnater amp. i am too, except for that.
i took apart the back of my rebel 30 combo, following the noise, and came to the conclusion that it is caused by the cover on (what i think are) the power tubes. it has a spring and the rubber that isolated it from the metal chassis is a bit thin, so i guess it doesn't always land comfortably.
i removed the covers and tried it. no noise.
i put them back as nicely "sitted" as i could, and now it hardly makes any noise.

maybe moving them around from manufacturer to seller makes them loosen a bit.
anyway, if you notice this on your amp, try removing the covers on the power tubes and nicely putting them back.
how to:
- unplug the amp
- wait a bit, read the "tubes are hot" warning.
- remember that some caps may hold voltage even after unplugged, so you can get a discharge if you touch what you shouldn't. i don't know if this amp has a discharge circuit. i'm not a tech. just don't touch what you don't need to touch.
- twist the cap until it alligns with the wider spot and can be pulled out.
- pull out gently, the rubber isolation thing doesn't not slide on the tube (rubber against glass) so you have to go gently. don't bend stuff.
- to put it back, again go slowly. be careful not to push from the top fully covering the hole on the cap with you finger, since this will build pressure inside. push from the top but don't cover the hole.

i'd guess the caps are for heat dissipation, protection, and perhaps also to stop vibrations. put them back, except if you know more than what the engineers who designed this know.

so, happy again. i'm taking my rebel 30 combo back home (from LA to uruguay).

salú

 

[ramblin390]

Thanks for the tip

 

[rrosa]

i've been doing some more testing, i though removing the caps had fixed the issue but it didn't.
haven't got any answer from egnater yet...

 

[shimmilou]

What happens if you just leave all of the covers off.

 

[rrosa]

i've removed all the power tube covers, i've also removed the metal plate that cover them.
i've tried pressing the other metal parts of the amp, in case they were vibrating, but it was not the case.
i didn't dare open the amp yet...

 

[JeepGuy04]

Hey, I listened to your clip. I have a rebel 30 and have heard that same noise. Your audio clip sounded familiar. I thought mine was maybe the power tubes rattling??? That was my best guess. I never swapped them out and right now I am working too much and have two young kids so I haven't been playing much lately. I would be interested to know what it is that causes that ringing sound.