As I only have one unit to go from, I was wondering if someone who owns a wm-10 can give me an idea of how much motor hum is present on normal playback though modern headphones? My unit behaves pretty well generally, but there is noticeable motor hum especially during silent sections. Any comments would be really helpful - thanks.
Thanks for your reply. I’ve tried running the unit without the casing as I wondered if the metal case might be causing an issue. Is there a common ground issue with the wm-10 that doesn’t involve the case?
If you check WM-10 schematics you will see that the case is used to connect h/p to the common Ground. Make sure that the points where screws, board and metal case are joined for the common ground are not oxidized. Re-flow the solder at the h/p jack, actually start here.
Stripped the unit down and cleaned the ground points with contact cleaner. I don’t believe that there is any improvement from the motor noise. It’s worse with sensitive headphones (which require lower volumes of course). interestingly the motor noise is reduced some what when pressure is exerted at various points of the unit when the boards are exposed. Not sure why this would be, but the search goes on to isolate the motor noise...
Did you reflow the solder joint for the ground connection to the headphone Jack sleeve? I dont know what you specifically mean by contact cleaner but those only remove oils. They wont help you in the case of Metal/Copper being oxidized