#1
Hey all. I think I have a problem with my Bugera 333XL that I have only had for a couple of months and only been able to use for a month and a half.

When I turn my amp on, I start getting a horrid screeching noise through my cab. The only way I can stop this is by either turning the tone knob on my guitar all the way to 0 or by turning the volume of my guitar to 0. It only seems to do it with high gain settings. I know what you're thinking at this point, "It's just feedback". However, if I turn the volume up for my neck pickup slowly, it causes even more screeching and crackling. It happened before during some live gigs recently but I have solved the problem by turning the amp off and changing my guitar lead. However during practice today it persisted even when changing leads and turning the amp off and on again.

Anyone know whats wrong? Could it be my guitar?

P.s. My guitar is an Ibanez SZR520
Main Rig
ESP LTD MH-350NT
Korg Pitchblack > Digitech Bad Monkey
Peavey 6505+ 112 w/ 2x12 (Celestion Vintage 30 and WGS Veteran 30)
[Effects Loop] Boss GE-7 > Boss CE-5 > TC Electronic Flashback
#2
It could be anything in your chain. Are you using any pedals?

Things to try:

1. Remove any pedals from in front (and effects loop) and plug directly into the amp.
2. Try different guitar cables.
3. Try a different guitar
4. Different Speaker cable.
5. Different head.
6. Different cab.
7. Maybe an amp setting is causing issue.

My guess would be there is something wrong with the head. The trouble shooting steps should help you narrow it down (provided of course you have access to other gear).
#3
I have no pedals or anything in my chain, just my guitar straight into the head. Next practice I'll swap guitars with the other guitarist and see if it does it with his. I really hope its not the head, I have a gig at the mid-end of march and it would be repaired by then. I'll check next practice.

Thanks
Main Rig
ESP LTD MH-350NT
Korg Pitchblack > Digitech Bad Monkey
Peavey 6505+ 112 w/ 2x12 (Celestion Vintage 30 and WGS Veteran 30)
[Effects Loop] Boss GE-7 > Boss CE-5 > TC Electronic Flashback
#4
Since you have another guitar player in the band, the fastest test for head trouble may be:

Use the other guitar players guitar head. Keep all the cables and your guitar the same. If the issue goes away, the problem is something related to the head.
#5
I will have a check when I next have access to my amp. If it IS the amp what is the problem, what do you guys reckon it will be? tubes?
Main Rig
ESP LTD MH-350NT
Korg Pitchblack > Digitech Bad Monkey
Peavey 6505+ 112 w/ 2x12 (Celestion Vintage 30 and WGS Veteran 30)
[Effects Loop] Boss GE-7 > Boss CE-5 > TC Electronic Flashback