After a long search and wait I have finally acquired a Sony WM-150. It came in good condition, although it does show signs of use. The person I bought if from said it worked completely although it needed a good cleaning and it was not completely co-operative functionality wise until a cleaning and constantly operating the player...working it in, warming it up. The speed is fairly good, but I hoped it would have less wow & flutter, my WM-F10 is still my ultimate winner for smoothest speed, believe it I had worked along time on it! I digress; I wanted this thing for its sound quality, the EX amorphous Head (with its high frequency response), the head dose sound great and I do notice the additional frequency response over my non-EX Head Walkmans, BUT my main issue is the noise...not tape-hiss (which is actually very low), the noise is a humming and buzzing in the background, which Becomes very annoying during quite passages in music. What could be the cause of this noise and how should I go about fixing it...Can anyone Please help?

ive got a Sony wm-f100 that does the same thing but just not as bad as yours. I think its the servo that controls the motor makes a bit of noise that i cant really hear in my Grados but i can in IEMs or earbuds. try checking solder joints and the belt. I think my belt tension is wrong and is overworking the motor. I might be wrong because ff and rew work just fine. I also believe the wm-f100 (the f-100 has sony logos embossed on the reels inside) and wm-150 use a similar transport btw

My wm-f100 does pretty good in the stability department but i notice the slightest wow and flutter because im used to listening to my wm-d6c and its a quartz locked servo controlled with the capstan being directly driven. incredibly low wow and flutter

edit: if you take the back of and look at the pc board make sure all the screws are tight because there is a screw usually that grounds the pc board to the case of the walkman and if thats loose or missing then it will be very noisy

It's the (SM) components electrolytic capacitors on the board are going bad, nothing you can do, It going to need a complete capacitor restoration, which cost around $120 and the cost of a service manuel.

i am curious,,why is it that some players develop this problem and other don't. i notice somtimes the belt deterioration changes from source to source. some belts seem to get brittle and either stretch or break while others turn to goo. i think climate plays a large part as to how parts fail...at least that's what seems to be happening.