#1
Hi

after jamming for an hour or so with my band, all of a sudden my amp(Marshall JCM 800 4210) started making horrible buzzing, crackling, God's fart feedback.
The weird thing is that the feedback only starts when im past 2 on the volume and sets in when i start playing.
sometimes it would not go away even if i turned the volume down on my guitar.
I never had this happen to me before and im just wondering if anyone has had the same problem or knows how i can fix it.

Thanks.
When the power of love overcomes the love of power, the world will know peace.
-Jimi Hendrix
Last edited by mw7 at Nov 4, 2009,
#2
If you're having amp problems, I feel bad for you son. I got 99 problems, but an amp ain't one.
#3
You can play past 2 with your 800?! Lucky sod

Could be microphonic valves? I'm not too sure, valve health isn't my forte

Epiphone Les Paul Standard w/ SD Alnico Pro II's
Fender Aerodyne Telecaster & Stratocaster
Marshall JCM 800 4104 combo


E-Married to Funny_Page
#6
no i havent tried it, but i will tomorrow cause my amps at school. im guessing if the tube is microphonic it will go ballistic when i tap it with a pencil?
When the power of love overcomes the love of power, the world will know peace.
-Jimi Hendrix
#8
Quote by mw7
no i havent tried it, but i will tomorrow cause my amps at school. im guessing if the tube is microphonic it will go ballistic when i tap it with a pencil?

with the eraser. and you will hear it through the amp if it's phonic.
I wondered why the frisbee was getting bigger, then it hit me.
#9
Quote by gregs1020
with the eraser. and you will hear it through the amp if it's phonic.


This.

Turn your amp on but do not plug your guitar in. Gently tap the tubes with the eraser on a pencil. If a tube is microphonic then sound will come out of the speakers.
#10
Quote by SwampAshSpecial
You left your JCM800 at your school? I wouldn't even wanna leave my Vox at school!!!!


haha its all good its locked up in the music room.

Quote by gregs1020
with the eraser. and you will hear it through the amp if it's phonic.

Quote by i_am_metalhead
This.

Turn your amp on but do not plug your guitar in. Gently tap the tubes with the eraser on a pencil. If a tube is microphonic then sound will come out of the speakers.

ahh true.
one more thing i forgot to mention, the feedback only started when i was on the overdrive channel with the gain on high.
when i played clean and lowered the gain it was fine.
is this too, a sign of microphonic tubes?
When the power of love overcomes the love of power, the world will know peace.
-Jimi Hendrix
Last edited by mw7 at Nov 4, 2009,
#11
To correct a bit: it's normal to hear a slight thump from tapping tubes. However if you hear a slight crackle then it's microphonic.
Quote by DeathByDestroyr
What the hell is a G&L.



Quote by Flux'D
Gay & Lesbian I think, the box smelled funny
Greg what did you send me??
#12
haha what kind of school do you go to that lets you keep your stuff in the music room?
#13
a good one

Thanks everybody for the help! ill report back tomorrow!
When the power of love overcomes the love of power, the world will know peace.
-Jimi Hendrix
#14
dude he lives in canada, they haven't invented stealing there yet!
Guitars:
LTD Alexi-600 White & Black
LTD Alexi-200 Black(Death Adder pickup & Gold OFR)
Agile Interceptor Pro 727 7-string
Jackson JS30RR rhoads
Jackson DKMGT
Squire telecaster

amps:
Bugera 6262 212 loaded with WGS veteran 30's
#15
Quote by Gundamnitpete
dude he lives in canada, they haven't invented stealing there yet!


#16
Quote by Gundamnitpete
dude he lives in canada, they haven't invented stealing there yet!


canadians are so laid back!

anyone seen that family guy episode when theyre talking about candians breaking out of jail?

im just gonna go out this door

ohkee be back soon
Quote by 23:50 inbleach
can't i just eat the fucking cactus?

Quote by WildChicken
Go suck a cat westdyolf!

Quote by Cat Of Pain
So, West...

I hear you'll suck my cat...

Ill suck your cat
PEACE LOVE PANCAKES
call me zach

chocolate chip pancakes!
#17
Quote by SwampAshSpecial
You left your JCM800 at your school? I wouldn't even wanna leave my Vox at school!!!!



i had my splawn at school. best 2j weeks ever

07 Fender American Deluxe Strat
07 Fender Custom Telecaster
09 Seymour Duncan Pickup Booster
09 Fulltone OCD V.4
10 Ibanez WH-10 V.2
09 Splawn SuperStock
10 Jet City JCA-20
97 Fender Hot Rod Deluxe

Yeh the SICK! bit sounds a bit stupid.

#18
Quote by Gundamnitpete
dude he lives in canada, they haven't invented stealing there yet!



What the hell is stealing?

Lol, I love my country. Funny thing is that family guy episode does actually sound like us haha.

It might be microphonic pickups as it happens when you have high gain which seems pretty normal for a pickup sometimes to feedback.
Agile AL3000
Douglas WRL90
SX SR1 STD Plus
J&D Strat
Squier Tele
Sammick TR2
Douglas Draco
Peavey JSX
Bugera V5
TWANGED VJ
#19
I'm not exactly sure what you're hearing... but it doesn't match my "experience" of microphonic tubes. Though microphonic tubes are probably the best bet of what's wrong.

Quote by SwampAshSpecial
You left your JCM800 at your school? I wouldn't even wanna leave my Vox at school!!!!


Oh... you got your Vox already?

After all the drama with your music teacher... lol
Quote by Blompcube
it's so cool to hate Gibson, even the federal Department of Justice hates them.

( )( )
( . .) This is Bunny. Copy and paste Bunny into your
C('')('') signature to help him gain world domination.
#20
alrightty! so i did the pencil test and the results for microphonic tubes are negative.
i think it might be the speaker or a volume pot in the amp?
When the power of love overcomes the love of power, the world will know peace.
-Jimi Hendrix
#21
Quote by mw7
alrightty! so i did the pencil test and the results for microphonic tubes are negative.
i think it might be the speaker or a volume pot in the amp?



Feedback may simply be caused by too much gain in your signal and your amp is naturally feeding back.

Crackling and buzzing may be signs of bad cables or a bad connection somewhere (i.e. output jack on the guitar, input jack on the amp, etc.).
#22
Quote by mw7
alrightty! so i did the pencil test and the results for microphonic tubes are negative.


It could be a false negative!
Quote by Blompcube
it's so cool to hate Gibson, even the federal Department of Justice hates them.

( )( )
( . .) This is Bunny. Copy and paste Bunny into your
C('')('') signature to help him gain world domination.
#23
WHY HASN'T ANYONE SUGGESTED PRE-AMP TUBES.
A new set of pre amp tubes may fix it, it sounds like one is bad.
Gear :

Ibanez RG2570 (has yet to post pics)
Crap Wal-Mart guitar that came in a 70 buck starters pack.
Marshall MG15, I know
#24
Quote by i_am_metalhead
Feedback may simply be caused by too much gain in your signal and your amp is naturally feeding back.

Crackling and buzzing may be signs of bad cables or a bad connection somewhere (i.e. output jack on the guitar, input jack on the amp, etc.).


yea i think too much gain might be it, but i need all that gain because it sounds so much heavier and badass.
The only reason why i think it might be the speaker is because it starts rumbling when the feedback kicks in.
a noise reduction pedal will probably do the trick right?

Quote by ragingkitty
It could be a false negative!


nah b, its not the toobz fo shizzy
When the power of love overcomes the love of power, the world will know peace.
-Jimi Hendrix
#25
why dont people start recording the nosies and put them up...wouldnt it be easier???
Gear:
Ibanez RG1527M Prestige
Martin DX1
Agile-2000
#26
Quote by mw7
yea i think too much gain might be it, but i need all that gain because it sounds so much heavier and badass.
The only reason why i think it might be the speaker is because it starts rumbling when the feedback kicks in.
a noise reduction pedal will probably do the trick right?


nah b, its not the toobz fo shizzy


No you don't, no-one ever needs a lot of gain.

Epiphone Les Paul Standard w/ SD Alnico Pro II's
Fender Aerodyne Telecaster & Stratocaster
Marshall JCM 800 4104 combo


E-Married to Funny_Page
#28
Ony Kerry King can play with gain, he is metal, look at his beard.

Its probably a gain issue or maybe cables.
Agile AL3000
Douglas WRL90
SX SR1 STD Plus
J&D Strat
Squier Tele
Sammick TR2
Douglas Draco
Peavey JSX
Bugera V5
TWANGED VJ
#29
:O

phonic tubes is the perfect excuse for an upgrade! Tell your parentals that it's a microphonic tube they might chip in a bit go read about a few different brands of tubes and try the ones you like the sound of
Guitars:
Gibson Les Paul Standard
Gibson Explorer New Century
Gibson RD Artist
Fender American Standard Telecaster

Amps:

Framus Cobra
Marshall JCM800 2203 - 1960A

Pedals:

Crybaby 535Q
Rockbox Boiling Point Overdrive
Last edited by R.D at Nov 6, 2009,