Tweet
I have been fixing up a DSL. It works well now that the valve PCB has been replaced. However there is some residual noise that is reduced if I jumper the input socket to the chassis. It sounds like a bad earth connection and I notice the the 10R resistor R1 which is part of the earth separation circuit on the pre amp is missing on this one.
From the schematics that I have from Marshall which are issue 1 and issue 5 it appears that R1 was dropped by the time of issue 5.
On other models these resistors are often burned out so I Wondered whether others have noticed this change on the dsl and knew the reason and any suggestion whether to leave it out our add it in.
Cheers Mike
Added schematicsJCM2-61-00 (1997) iss1.pdfJCM2-61-00 (2002) iss5.pdf
From the schematics that I have from Marshall which are issue 1 and issue 5 it appears that R1 was dropped by the time of issue 5.
On other models these resistors are often burned out so I Wondered whether others have noticed this change on the dsl and knew the reason and any suggestion whether to leave it out our add it in.
Cheers Mike
Added schematicsJCM2-61-00 (1997) iss1.pdfJCM2-61-00 (2002) iss5.pdf