MARK IV noise trouble

[fatbagg]

Hey my mark IV makes these strange noises but only when I turn up to like 3(master) or so...Ive switched tubes, and that doesnt make the difference...can anyone tell me anything maybe, or have any type of advice? The noise continues even while playing, loud crackling feedbacking noise (not due to tubes).

 

[Platypus]

From the manual:

Your MARK IV is capable of playing very loud as well, but it is not feasible to play with high gain and high volume simultaneously without causing squealing, feedback and excess noise. So remember to balance “gain” with “volume”. In the LEAD mode, a general guideline might be push in the BRIGHT for loud playing and pull out the BRIGHT at lower volumes.

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.

 

[MusicManJP6]

If you are certain it is not tubes, then double check ALL cables, big or small... and your guitar's input connection as well.

Just to be sure: What steps did you take to ensure it is not tube related?

Platypus might be on to something as well. Mid gain is good for low volume (kind of like loudness on a stereo) but can cause problems at higher volumes.

Good luck and let us know what you find out...

 

[fatbagg]

Well, I have about 4 tube sets (all tubes for mark IV) and switched them all out with everyset and didnt change. NOw, While playing loud, the ONLY switch I pull is fat, should I not? I use pentode, + harmonics, as of now, fo rI am currently searching how to find a smoother bubbly lead sound that isnt so smudgy for the neck position...which may not be possible with a heavy mahogany set neck (while retaining a thick, clear bridge tone)..any help here as well?