#1
so i was rehearsing with my band yesterday and out of nowhere my tube head started making some weird rattling/vibrating sounds trough the speaker and i got really freaked out i thought i had broken my cab, anyways i tried the cab with another head and its perfect.

i put the volume at 0 on my amp head and started playing and noticed the buzzing/rattling can be heard from where the tubes are.

you can hear it trough the speaker and with no volume.

does this mean i have to change my tubes?

or is my adored head gone u.u

thank you.

EDIT: I just noticed i get very high pitched 'squeals' out of nowhere
mocrophonics?
Last edited by pebbles123 at Dec 13, 2008,
#2
i just read something on 'microphonic' preamp tube...
anyone know if this could be the culprit
#3
That does sound like that could be it.

Never heard of that amp but can you find the preamp tubes?

You can pull one out, get it's model number, maybe find a new one locally and rotate the new tube thru one by one until you find the potential bad one. Or you can buy all new preamp tubes.

This may not even be the issue. It's possible I guess you have a loose insert jack on guitar or amp or something else. So what was the other amp you tried?
#4
Quote by 311ZOSOVHJH
That does sound like that could be it.

Never heard of that amp but can you find the preamp tubes?

You can pull one out, get it's model number, maybe find a new one locally and rotate the new tube thru one by one until you find the potential bad one. Or you can buy all new preamp tubes.

This may not even be the issue. It's possible I guess you have a loose insert jack on guitar or amp or something else. So what was the other amp you tried?


yeah it has 12AT7 preamp tubes, i was looking on upgrading them to 12AX7 for a bit more gain


that was a good idea mate! and since i have no money and im poor (and would have to order these online since in Mexico they are hard to get) that might be a good thing to do.
loose insert jack? what do u mean on the amp? all the inputs seem and feel nice and tight
the guitar and cables are good too i just cant see how the EXTREMELY low volumes and weird crackling/rattling being caused by a bad cable.
i tried my cab with a small amp that has a speaker output and trough a friend of mines mg head xD
LOL
thanks.
any input from all of the tube experts would be appreciated.
#5
good deal.

i was only throwing out different ideas. Sometimes these things are hard to trouble shoot. One time I plugged my amp into the same power strip as all my pedals just to see what would happen and got all kinds of hell crackle. If your jacks are secure then that's prolly not it obviously.

good luck
#6
1) Fiddle around and see if the problem occurs in all channels, or in just one.

2) Find a diagram showing which tubes work with what channel.

(This can sometimes narrow down which tube is causing the problem and save you some time and labor.)

3) With the amp ON and the lights dimmed, tap on each tube with something that is not metal, like a chopstick. Look for the tube to glow differently and listen for an increase in the microphonic sound.

4) If problematic tube is located, replace.

If this doesn't do it, then its out of my expertise
#7
Quote by thrasher_s
1) Fiddle around and see if the problem occurs in all channels, or in just one.

2) Find a diagram showing which tubes work with what channel.

(This can sometimes narrow down which tube is causing the problem and save you some time and labor.)

3) With the amp ON and the lights dimmed, tap on each tube with something that is not metal, like a chopstick. Look for the tube to glow differently and listen for an increase in the microphonic sound.

4) If problematic tube is located, replace.

If this doesn't do it, then its out of my expertise

it only has one channel mate
anndd a diagram would be impossible to find for this model x3
im goin to try the advice num 3
thnk you!
anyone else got any ideas?
#8
oh man i just found out i cant get el34 in mexico around this tiem: (
they sold out everywhere
u.u
anything else i can put on my amp?
#9
you can look for kt88,6L6 tubes if you amp can take these tubes.
ESP Vintage 4
Fender American Special Jazz
Fender American Deluxe Precision
Ibanez SR700
Jackson DXMG
Fender American Standard Telecaster
SWR Black Beauty
Orange Thunderverb 50


Modulus Quantum 5 fund-$2150/$3369
#10
ok my amp needs 200 dollars for fixing(tube change and bias)
its down and out and itl be this way for a long long while
u.u
thank friends!