Feedback on 5:50's burn channel

[Trea]

Hello,

I've recently purchased a 5:50 and so far am loving the amp. The only issue is that the amp seems to feedback really bad at around 50% on the master volume on the burn channel. It does this even when the guitars volume is off. This only occurs on the burn channel and happens regardless of gain setting. The only thing I can do to make it stop is turning the volume down. Any ideas what might cause this?

Thanks in advance

 

[Old BF Shred]

It could be a tube that's gone microphonic (usually V1)........it will definitely cause this.
Try swapping out V1, even with another tube in the same amp in another position.
Even if it's a new amp, could have a defect tube.

If it still happens, then you may have really hot, high output p/u's (you did not say). But, then again, if the volume is all the way down....
Also try EQing mid and treble down a bit to see if it clears up.
Even try another guitar, if available.
Still sounds like a tube to me......

Good luck!

 

[Newysurfer]

Hello,

I've recently purchased a 5:50 and so far am loving the amp. The only issue is that the amp seems to feedback really bad at around 50% on the master volume on the burn channel. It does this even when the guitars volume is off. This only occurs on the burn channel and happens regardless of gain setting. The only thing I can do to make it stop is turning the volume down. Any ideas what might cause this?

Thanks in advance

geez Trea - what guitars are you using with what PUP's. No-one can help you without that info.
Tell us when, and how, and with what, the feedback goes berserk.

 

[Trea]

Hello,

I've recently purchased a 5:50 and so far am loving the amp. The only issue is that the amp seems to feedback really bad at around 50% on the master volume on the burn channel. It does this even when the guitars volume is off. This only occurs on the burn channel and happens regardless of gain setting. The only thing I can do to make it stop is turning the volume down. Any ideas what might cause this?

Thanks in advance

geez Trea - what guitars are you using with what PUP's. No-one can help you without that info.
Tell us when, and how, and with what, the feedback goes berserk.

I've tried different ones. Les Paul Classic with SD Pearly Gates, Ibanez AS73 with stock pups, Tele with stock pups. Makes no difference so I don't think that it's the guitar. I'll try the tube swap mentioned above today. Like I mentioned tho, this only happens on the burn channel once the master gets around halfway. Thanks for the help so far guys.

 

[Newysurfer]

Definitely an amp issue then - either faulty tube or something else needs repair.

 

[UKBoogieboy]

I could not even use the gain channel on the F50 because of the squealing even at low volume, just on!!!!!!!!!!!!!!!!!!!!!!! It was microphonic valves.
Use a jack plug with a metal case plugged into the input, then tap the case, does it ring? If yes, you nead new valves, replace them all if you can, other wise you can go round and round withough finding the problem.

 

[J.J]

Make sure the reverb is set low or off on the Burn channel. The reverb can cause feedback, particularily on the burn channel as it has the highest gain. The manual warns about this (yes, I'm a cop out and have read it )

 

[gezza]

Hey Guys,

Just wanted to chime in.

1. Can you post your amp settings, especially the Burn Channel?

I would guess, but the master volume at 5/10 half way, would be F/ Loud.
Where is your Gain set to??
I have the Mesa 5:25 and don't get past 2 - 3/10 on the Master Volume. I used to own a Marshall JVM410C 100watt combo, the Mesa is as loud on those settings as my 100watt Marshall.

Also, If you are getting squealing and you turn the volume of the Guitar all the way off and it still squeals, it's not the guitar.
I would also suspect your Preamp tubes, also if you are running any extra gain pedals.

Hope we can help you,

Gezza.

 

[MrMarkIII]

If you change pre-amp tubes, switch them out one-at-a-time. Then sound-check, then move on to the next tube, if neccessary.
If you just replace all of them at once, you won't find out which tube is microphonic, and you may not solve the problem. It's quite possible to replace a bad tube with another, even if it's brand new. The manual has a chart explaining which tube does what.

 

[Trea]

Mesa is sending me out a new set of tubes. I will replace them and let you guys know what the result is.

Thanks for all the help and suggestions. I love this place!