Post by crimsonqueen on Nov 9, 2022 9:34:11 GMT -7
I have been playing a Z28 head for about 5 years, now. It's a 15th anniversay model (2004?).
Since a screen resistor burned up, it's never been the same. I also was blowing fuses and I had to change the rectifier. The amp is on its third rectifier since I got it. The first one was not the correct type.
The amp is biased at 28mA.
I had a service technician look at it. He fixed some grounding issues that were generating noise. The amp is now super quiet, but I am still having a chronic problem.
I gig once every couple of months with it (original band), but rehearse every Sunday for about 4 hours.
Over time, the amp gets brighter and brighter, and loses its midrange. The high end also gets harsher with unpleasant overtones. I have many different types of speakers. This is not with one speaker in particular.
They other day, it lost a lot of volume. I turned it off without going to standby first and the volume came back just as the amp was about to turn off.
To remedy the harsh brightness, I added a cut control, which helps, but only temporarily. The main problem is that the sound of the amp changes a lot, and constantly. After a while, humbuckers start sounding like single coils and all pedal settings need to be changed. The amp tone gets scooped and harsh.
I have never had an amp do that in 42 years of playing. I love this thing when I first turn it on, but "that sound" does not remain consistent.
What could be causing this? I can repair anything in the amp, and so can the tech I saw, but I can't diagnose this kind of issue.
I appreciate any help. I want to keep using and loving this amp.
Since a screen resistor burned up, it's never been the same. I also was blowing fuses and I had to change the rectifier. The amp is on its third rectifier since I got it. The first one was not the correct type.
The amp is biased at 28mA.
I had a service technician look at it. He fixed some grounding issues that were generating noise. The amp is now super quiet, but I am still having a chronic problem.
I gig once every couple of months with it (original band), but rehearse every Sunday for about 4 hours.
Over time, the amp gets brighter and brighter, and loses its midrange. The high end also gets harsher with unpleasant overtones. I have many different types of speakers. This is not with one speaker in particular.
They other day, it lost a lot of volume. I turned it off without going to standby first and the volume came back just as the amp was about to turn off.
To remedy the harsh brightness, I added a cut control, which helps, but only temporarily. The main problem is that the sound of the amp changes a lot, and constantly. After a while, humbuckers start sounding like single coils and all pedal settings need to be changed. The amp tone gets scooped and harsh.
I have never had an amp do that in 42 years of playing. I love this thing when I first turn it on, but "that sound" does not remain consistent.
What could be causing this? I can repair anything in the amp, and so can the tech I saw, but I can't diagnose this kind of issue.
I appreciate any help. I want to keep using and loving this amp.