Hi everybody
I have a Mesa Boogie 50 caliber + head that recently developed noise problems. The amp is quiet with no cable inserted but gets noisy with the guitar plugged in
The first thing I have done is replacing all preamp tubes with other tubes selected for low noise in other amps.
This unfortunately didn't solve the problem. I even tried replacing the power tubes, they are not the cause.
There is a very weird kind of noise, it sounds like hum but also has a flanging/phasing component to it. Also it suddenly would go up and down in volume
I have recorded a short sample of the noise problem. You can hear at 00:15 the noise going up in level, then it turns down again at 01:04
https://www.dropbox.com/s/oze8kogyki...01_01.mp3?dl=0
I absolutely have no clue what is the cause of this noise problem. I checked the pcb for dry joints and bad connections but everything seems to be fine and looks like these amps are very well built
I really hope someone could give any troubleshooting suggestions. I have access to a scope but I am kind of lost, would be great if anybody recommend which parts of the circuit to check
I have a Mesa Boogie 50 caliber + head that recently developed noise problems. The amp is quiet with no cable inserted but gets noisy with the guitar plugged in
The first thing I have done is replacing all preamp tubes with other tubes selected for low noise in other amps.
This unfortunately didn't solve the problem. I even tried replacing the power tubes, they are not the cause.
There is a very weird kind of noise, it sounds like hum but also has a flanging/phasing component to it. Also it suddenly would go up and down in volume
I have recorded a short sample of the noise problem. You can hear at 00:15 the noise going up in level, then it turns down again at 01:04
https://www.dropbox.com/s/oze8kogyki...01_01.mp3?dl=0
I absolutely have no clue what is the cause of this noise problem. I checked the pcb for dry joints and bad connections but everything seems to be fine and looks like these amps are very well built
I really hope someone could give any troubleshooting suggestions. I have access to a scope but I am kind of lost, would be great if anybody recommend which parts of the circuit to check