Tweet
Hello and thanks for taking the time to help. I am having issues with the preamp section of my amp and am hopeful that someone can point me in the right direction. Being a appliance service tech for 23 years and previously in the IT field before that I am no stranger to reading a schematic and working with a soldering iron and wish to repair the issue myself vs taking it to a repair center. The problem I am having is that when the amp is on and running, my clean channel is louder than normal at any given volume and the gain channels are tinny without volume or crunch. An example would be on clean and at volume 1 it would sound as if the volume is on 6 and the eq knobs almost act like a volume sometimes. On the gain side of things you have to run both gain and volume knobs to almost max before hearing any signal.
The power side of the amp works great as I can run my Boss GT100 in 4 cable and its nice and loud ( through effects loop ) so I know the issue is limited to the preamp on the B52.
Initial thoughts were that my tubes may have an issue so I bought all new tubes and re-tubed the entire amp and also re-tensioned the sockets before installing the tubes. I re-biased the amp according to the manufacture and still had no change in operation.
After all that I opened the case up and saw that a few of the capacitors had a nice dome on them ( the kind of dome when a cap has reached the end of the line) so I replaced them with ones of similar ratings and noticed that the power and effects loop sections were now better but still no change in the preamp operation.
I looked over the schematic in hopes of finding the issue and also looked over the board for the obvious blown resistor or diode and did not find any and also am not sure where to start on the amp to trace signal on the schematic to find my problem.
I hope that someone has had a similar instance and can help point me in the right direction as I would like to use the preamp in the b52 along with my gt100 and fully use my setup.
Thanks in advance for advice.
The power side of the amp works great as I can run my Boss GT100 in 4 cable and its nice and loud ( through effects loop ) so I know the issue is limited to the preamp on the B52.
Initial thoughts were that my tubes may have an issue so I bought all new tubes and re-tubed the entire amp and also re-tensioned the sockets before installing the tubes. I re-biased the amp according to the manufacture and still had no change in operation.
After all that I opened the case up and saw that a few of the capacitors had a nice dome on them ( the kind of dome when a cap has reached the end of the line) so I replaced them with ones of similar ratings and noticed that the power and effects loop sections were now better but still no change in the preamp operation.
I looked over the schematic in hopes of finding the issue and also looked over the board for the obvious blown resistor or diode and did not find any and also am not sure where to start on the amp to trace signal on the schematic to find my problem.
I hope that someone has had a similar instance and can help point me in the right direction as I would like to use the preamp in the b52 along with my gt100 and fully use my setup.
Thanks in advance for advice.
Comment