Hi All, I'm very new to the Sonyt WM restore scene. I recently picked up a nice WM-109. I've since replaced the band that was completely destroyed and the unit seems to play and function ok. With one exception - the audio is very very low. If I turn the volume knob the volume goes up and down, but at the highest level the audio is incredibly low. Any suggestions on how I can start to felt find and resolve? Thanks Sonny
Try to resolder the audio related components like chips, caps, etc. Or maybe you have to replace them
First thing I would check are the output coupling capacitors C118/C218, this symptom is typical of coupling caps that have very high impedance. Service manual is available here: https://walkman.land/document/164/sony_wm-109_manualpdf
So the good news is I got the two capacitors off without too much trouble The bad news is I'm having trouble sourcing two very small 330 uF capacitors. I have tried Mouser and Digi-Key but I can't find an electrolytic capacitor that has the same diameter and height. Either the height is right but the diameter is too big or the diameter is right but the hight is too big. Any suggestions on sources?
If it's that long thin type, you're not going to find a replacement in the same footprint. Solution is to replace with SMD tantalum instead. Something like this: F950G337MAAAQ2 KYOCERA AVX | Capacitors | DigiKey Don't worry it's a differnt type, tantalums have been used by the manufacturers as coupling capacitors and they perform just fine.
Ok. So I finally got some caps from Digikey and replaced the two suggested. Unit seems to be a little better but sounds "fluttery". Any suggestions on what's next?
Flutter can be from many things, including (but not limited to): a loose belt, unstable tape path at the capstan/roller due to improper alignment, a polished capstan, worn capstan bearings. The WM-109 being an autoreverse walkman, first thing to see is if this high flutter is present on both sides or just one. Being on both sides suggets the problem is likely external of capstans/rollers, while being just on one side would suggest something on that capstan, bearing or roller. Suggest reading this thread for more in-depth generic info about W&F: https://stereo2go.com/forums/threads/wow-and-flutter-my-know-how.19/
Id suggest cleaning the speed pot, or cracking open the motor cover to check if any gunk got inside, ive had goop seep into those flat motors which caused speed issues before. Got my money on the pinch rollers being the main problem though. They were always the culprit with my wm-100 models.
