Hello Walkman Wizards, I recently picked up a Sony WM-2 to recreate a childhood memory. It needed service, so I dove in completely. I followed the standard overhaul procedure for this model (as described in great detail by @Valentin). Here is a breakdown of what has been done so far: Center Gear & Clutch: This unit has that thick plastic center gear and is not cracked. I still completely disassembled it and polished the clutch to remove all patina, just in case. Mechanicals: Cleaned and relubed the capstan bearings, greased the appropriate points, and added a few drops of oil to the motor shaft. Belt Path: Polished all surfaces that interact with the belt. The transport runs whisper-quiet and feels mechanically excellent. The Belt: Replaced the old belt with a brand new Russell Industries SCY5.2 (IC=5.2", C/S=0.035", Wall=0.035") from their PRB line catalogue, which corresponds to Sony part 3-578-222. Tape Path: Kept the original pinch roller as it looks and feels okay with no obvious deformation. The tape path looks correct when checked with a mirror tape. While I don't have a torque test tape, the take-up tension feels right in my fingers; it is on par with my other decks. The Problem Despite the smooth mechanical overhaul, I am getting an incredibly high Wow & Flutter reading of 0.78% RMS. Yikes! When looking at the speed analysis, the dominant spike shows up right in the 8 Hz domain, which points toward a capstan-speed issue. By the way, I did not do a Ferric Chloride etch on the capstan, so it remains smooth and shiny like a standard cassette deck's shaft. Questions for the Experts: The Belt: Would sourcing a specialized belt (like from Marian's FixYourAudio) make a significant difference for this 8 Hz spike? The Pinch Roller : Could a new pinch roller help this? Any insights or troubleshooting points for the WM-2 transport would be greatly appreciated! Thanks!
Update: After a day of unsuccessful tinkering with the usual suspects, my W&F was still sitting stubbornly high at 0.67% RMS. I finally decided to pull the belt and manually recalculate its inner circumference (IC). Bingo—it turns out the Russell Ind. PRB catalog specifies the wrong size for this model. An IC of 5.2" is simply too short and causes excessive tension on the transport. A 5.4" IC is a much closer match for the required 44mm diameter path. Lesson learned: trust, but verify! At least the wall thickness was a correct 0.035". Expecting a package from Marian at fixyouraudio with the right stuff in a couple of weeks.
@euroflash: Alex - I have purchased from Marian for one of my Sony Walkmans, but haven't installed the belts, yet. I, also, got four left pinch rollers coming from him for my Sony TCM-200 tape transports on my Sony TC-K950ES and TC-K700ES decks. Nando.
One thing I want to add: the belts from Russell Industries are one of the best you can get. But of course the diameter has to be right: you have to measure to double check, wouldn't rely on SONY part numbers alone. I don't have a measurement specifically for WM-II, but I think it should be close to TPS-L2 which is 45mm x 1mm (inner diameter x thickness). Wouldn't replace the roller if it looks good, on this mechanism excessive W&F is rarely caused by pinch rollers unless they are visibly damaged (glazed, hard as a rock, indentation mark). Usually this is more of a problem on walkmans with very small rollers (such as WM-EX series), in such walkmans the roller pressure is also smaller so even a roller that visually looks good can cause traction problems. Also keep in mind some of the new rollers available have eccentricity, so that's something to be check if a new roller is installed as there can be situations where replacing it adds a problem that wasn't there before.
@Elite-ist Nando, I’ve installed pinch rollers from Marian on my Sony TC-K679ES and AKAI GXC-760D, and his products are always of excellent quality. @Valentin, Thank you for the insight. The service manual for the WM-2 specifies 44 x 0.9 mm, so this new length should be a perfect fit. I’ve ordered many belts from Russell Industries over the years, and they’ve always been great for my decks and boomboxes—this was entirely my mistake for relying blindly on their catalog number for this specific Sony. Thanks also for the heads-up regarding eccentricity in some new pinch rollers; that is definitely a good variable to keep in mind. I'm crossing my fingers that the drop in tension from the correct belt is all it takes to tame this high W&F. This is such a nice Walkman, I'd hate to see it end up as a "souvenir" on a shelf!
