Help controlling some feedback with my Mark IV....

[Mizati20]

Hey guys, I've owned my Mark IV for awhile now, I just recently started playing with a band meaning I'm using it at much louder volumes than I have been. My question is, I'm getting a bit of unwanted noise while playing, to be more specific, during a couple breakdowns where there will be a progression of palm mutes and then a pause for a couple beats, during that pause I get a loud humming noise, even when muting with both hands. I'm running a Boss Noise Suppressor, and I have my output around 3 and my lead channel volume around the same. Like I said I'm just now getting into the territory of running the amp very loud, I was curious if off-setting the Channell Volume and output volume would help, maybe switching up the triode / pentode or mid gain/ harmonics would help? I know this is something I could figure out by messing with the amp, but with the amp that loud and have to stand close to it to keep playing with the settings, I produce feedback from being so close. While jamming im standing a good distance from the amp so I dont think that's the problem.

Currently I'm running a hard v in the eq, drive and gain around 7-8, presence at 4 to 5 pulled, bright pulled, Mid Gain and Pentode, simulcass and full power.

Any help or suggestions / advice would be awesome.

I've always had good luck posting here, you guys are the ****, thanks in advance for any and all help, cheers my friends.

Kit

 

[Platypus]

Hey guys, I've owned my Mark IV for awhile now, I just recently started playing with a band meaning I'm using it at much louder volumes than I have been. My question is, I'm getting a bit of unwanted noise while playing, to be more specific, during a couple breakdowns where there will be a progression of palm mutes and then a pause for a couple beats, during that pause I get a loud humming noise, even when muting with both hands. I'm running a Boss Noise Suppressor, and I have my output around 3 and my lead channel volume around the same. Like I said I'm just now getting into the territory of running the amp very loud, I was curious if off-setting the Channell Volume and output volume would help, maybe switching up the triode / pentode or mid gain/ harmonics would help? I know this is something I could figure out by messing with the amp, but with the amp that loud and have to stand close to it to keep playing with the settings, I produce feedback from being so close. While jamming im standing a good distance from the amp so I dont think that's the problem.

Currently I'm running a hard v in the eq, drive and gain around 7-8, presence at 4 to 5 pulled, bright pulled, Mid Gain and Pentode, simulcass and full power.

Any help or suggestions / advice would be awesome.

I've always had good luck posting here, you guys are the sh!t, thanks in advance for any and all help, cheers my friends.

Kit

Hey there Kit, here's some helpful info from the Mark IV manual:

As the setting of the LEAD DRIVE control is increased, the MID GAIN continues to add huge amounts of extra boost, which at some point will become overwhelming and will cause unnecessary noise, squealing and feedback when used in conjunction with the LEAD BRIGHT and LEAD FAT switches. For loud high-gain lead playing most seasoned veterans will prefer the switch in its HARMONICS position

Hope that helps!

 

[Boogiebabies]

The pull bright is a beast to tame at higher volumes. WHEEEEEEEEEEEEEEEEEEE !!!!!!!!!
I found screening as many high grade tubes as possible lowers the risk of microphonics.
I went through about 12 GT 12AX7M's before I got one that could handle the pull bright without screetching.

 

[mshifflett]

I had a similar situation happen to me with the lead channel. After the last retube it is gone though. I changed my tube configuration and things are much better, inlcuding the tone