#1
I've had this amp for quite a while now and just before my last deployment (6 months ago) my amp stopped working properly. Now when i turn the power and the standby on it makes a horrible screeching noise. It happens on every channel i turn it to.

When their is no cable plugged in its's suppose to have a "light show". All of the lights flash and whatnot, but now it no longer does that and acts like their a a cable plugged in at all times. I was thinking it might be a input problem because the whole has always been loose, but i have no evidence to suppose that.

Has this happened to anyone else or does someone who knows about amps?

I would like to try and fix this myself before I either take it to a repair shop and spend an arm and a leg or try and sell it for way less than someone should.

Please and Thank You.
#2
check the tubes. thats really thing i would do first. tap them and see if anything changed. i use the eraser end of a pencil, if you hear more noise through the amp you have got a bad tube. its gone microphonic.

if they are stock tubes, you should replace them anyways.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
2017-07-07 2017-07-07 Update and a Chat On Noise Constraints *** NEW FRIDAY 7/7
2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
2017-03-02 - Guitar Philosophy 1001- Be Prepared For the Situation (Thursday 2017-03-02)
2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#3
Quote by trashedlostfdup
check the tubes. thats really thing i would do first. tap them and see if anything changed. i use the eraser end of a pencil, if you hear more noise through the amp you have got a bad tube. its gone microphonic.

if they are stock tubes, you should replace them anyways.


They are stock, but the tubes are fine. I just checked them.
#4
Not sure if the fx return has % control, if all the way up bypasses the preamp. Maybe sticking a cable connector in the send will bypass it if it doesn't have the other option. Let us know if you have squeal if you stick only one connector in fx send, no connector in fx return. If it is quiet you can try plugging the guitar through another cable in the fx return, if you get clean sound maybe it is the preamp section.
By what you describe if it isn't a tube I'd guess you need a tech.
#5
^ They don't have an FX loop.

Quote by Blckspawn
They are stock, but the tubes are fine. I just checked them.

How did you check them? This sounds like a microphonic tube to me.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
Last edited by Cathbard at Nov 24, 2014,
#6
Quote by Cathbard
^ They don't have an FX loop.


How did you check them? This sounds like a microphonic tube to me.



+3.1415 that was what i thought from the beginning.

and OP you should have an extra set of tubes on hand. for ****s sake its only three tubes. <$60 then the will work great.

also if i ever that comes new with unbranded tubes, i will roll a full set in to it. a lot of manufacturers will give your shit tubes a quick swap and you are good to go.
WTLT 2014 GG&A

Quote by andersondb7
alright "king of the guitar forum"


Quote by trashedlostfdup
nope i am "GOD of the guitar forum" i think that fits me better.


Quote by andersondb7
youre just being a jerk man.



****** NEW NEW NEW!
2017-07-07 2017-07-07 Update and a Chat On Noise Constraints *** NEW FRIDAY 7/7
2017-04-13 RUN AWAY from COMPUTERS!!! TCE? RANT ALERT!!!
2017-03-02 - Guitar Philosophy 1001- Be Prepared For the Situation (Thursday 2017-03-02)
2017-02-21 How to Hot-Rod the Hell of your Stratocaster for $50! (Tuesday 2017-2-21)
Resentments and Rambling from a Guitar Junkie
---> http://trashedengineering.blogspot.com/
#7
Quote by trashedlostfdup
+3.1415 that was what i thought from the beginning.

and OP you should have an extra set of tubes on hand. for ****s sake its only three tubes. <$60 then the will work great.

also if i ever that comes new with unbranded tubes, i will roll a full set in to it. a lot of manufacturers will give your shit tubes a quick swap and you are good to go.


Okay, I just plugged it in and turned it on completely till i started hearing the noise from the amp. I tapped each tube (out of the 3) and heard some echoing into the speaker. I think this is what you guys are talking about, but im not too sure.

I now know what kind of power tubes I need, but im dont really know if their is a specific type of pre amp tube. It doesnt seem to say on the tube itself...any ideas?

-edit- I found all of the tubes i need. Hopefully this works. If it does, then thank you all for helping my ******ed ass. If not, then Ill keep looking.
Last edited by Blckspawn at Nov 24, 2014,
#8
It's not a preamp tube, it's a phase inverter. It's a 12AX7/ECC83.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#9
What Cathbard said is technically correct. The 12AX7 'Pre amp' tube you are looking for is a Phase Inverter in this case. I'd get a JJ 12AX7. That's what I have in my Vypyr 60. You may also still want to get that insert jack repaired as that will just get worse. I think you can tighten it from the inside.

And yeah, buy 2 - 12AX7s so you have a spare

www.eurotubes.com
www.dougstubes.com

Just get a regular one - don't concern yourself with:

High gain
Gold pin
Pre Tested
Low Noise
blah bla blah