mansinmind
New member
Hello all,
So my vh4 has been red plating and I hear what sounds like a 60hz hum coming from the speaker after about 30 minutes so today I went ahead and took off the shell to check the bias following the manual instructions. After letting the amp run on standby for 5 minutes I switch over and the bias was a little low so I move it to 65mA and watch my meter to see if it fluctuates but it started climbing steadily. I turn the amp off before it reached 70mA. I tested the other leads to see what mA it read but I got 0.00 on the meter. Connected the red and black wires again just like in the manual and now its also reading 0.00.
I didnt want to mess with it so I put everything back together plugged in my guitar and it sounds fine, just like any other day but I didnt leave it on for more than 5 minutes. What might be going on? bad tube? bad transformer? A picture of the red plating tube is attached and looks "dirty" inside.
Yes, the amp is set to 6L6, no burn smells, no noise, buzzes etc.
So my vh4 has been red plating and I hear what sounds like a 60hz hum coming from the speaker after about 30 minutes so today I went ahead and took off the shell to check the bias following the manual instructions. After letting the amp run on standby for 5 minutes I switch over and the bias was a little low so I move it to 65mA and watch my meter to see if it fluctuates but it started climbing steadily. I turn the amp off before it reached 70mA. I tested the other leads to see what mA it read but I got 0.00 on the meter. Connected the red and black wires again just like in the manual and now its also reading 0.00.
I didnt want to mess with it so I put everything back together plugged in my guitar and it sounds fine, just like any other day but I didnt leave it on for more than 5 minutes. What might be going on? bad tube? bad transformer? A picture of the red plating tube is attached and looks "dirty" inside.
Yes, the amp is set to 6L6, no burn smells, no noise, buzzes etc.
