Hi, Some time ago I renovated a DC2 and also changed the center gear. I follow the guide "Sony DD series step-by-step repair guide for dummies" an all seemed well. It played fine for some months then I noticed that wow and flutter increased, not much but noticeable. I could not locate the capstan wheel plastic ring on the capstan axle which could explain the issue. I looked inside the axle but to no avail. I then decided to borrow it from a DD30 I have but to my surprise I could not locate one there either. I see no direct signs that these walkmans has been in service before so I was quite surprised. I have now put some oil as described in the capstan axel and have adjusted top screw. Wow and flutter is now excellent again. This time I secured the top screw with some lacker in case that was the problem. What is your experience regarding this plastic ring? Is it on all DD walkmans? Did I just not see it inside the axle? Will it work ok without it? Could it be lack of locking the screw that cause the change? If anyone have a spare or two I would be happy to buy it.
I think the correct term is "washer" for the part you are reffering to, not "ring". The answer is yes, it should be present on all walkmans, not just SONY, not just DD. The walkman will work without it, but the wow&flutter will increase, especially when unit sits in normal position (buttons up) and when you shake it because there will be increased friction between flywheel and capstan bearing. In time, this will also create wear, as it's a metal on metal contact and the surfaces are not perfectly flat so oiling won't help too much. So putting a washer back is the only solution. Most older generation DDs that I have repaired have a black washer, which is pretty hard to miss: if it is there you will see it. The DD33 for example (last in DD generation) has a transparent washer, but even that one can be seen if you look carefully. If the lock paint on the flywheel retainer screws was intact, the washer should be there. Otherwise, it means someone else has opened it before and has lost the washer. Maybe you have lost it yourself when you changed the center gear. Increased wow&flutter can be caused by many things: - increased friction in the mechanism; - flywheel thrust play too high or too low; - motor not perpendicular to flywheel (there is an ajustment that needs to be done after rubber ring replacement); - a piece of tape becoming loose on the motor rotor, causing increased friction; - incorrect servo adjustment or servo problem; Have you measured the wow&flutter using WFGUI ? It should be 0.08% WRMS or lower if all the adjustments are correct. I don't have washers for sale and recommend posting in "Gear that you want" section and ask there for those.
Thanks Valentin, Yes, washer is a better name for it. There is something black inside/around the axle on both walkmans, it didn't come out so I thought they maybe were not the washers I was looking for. I'll see now that I have used lock paint on the screw if it will stay stable. Maybe this is the likely cause as it has been very stable for a long time and I could adjust it back to be stable again so maybe the top screw has moved a little by itself. Unfortunately I haven't been able to properly measure as I understand there is only a PC meter SW not for Mac. I've used an oscilloscope to inspect movement of the sinus in the frequency axle. Not a really good way but I can easily see how instability increases when I tighten the screw to hard or too loose. Also compared the output on the scope with my D6C. I also measured the current draw. Also my ears are quite sensitive to WF. Many thanks for your help!
If there is something black, that's the washer. It measns your problem was the flywheel thrust play adjustment, not the washer. If you locked the adjustement screw you shouldn't have any more problems. I also recommend adjusting the motor position, given the new ring is of different thickness and hence something that usually needs adjustment. You can adjust it by eye, so that when you look perpedicular to the flywheel, both "edges" of the spindle are seen equally, not one more on the inside than the other. The current draw should be 98mA (without a cassette inserted, without headphones) on the DC2. Measurements that I did in the past indicate that when adjustements are good, the consumption is pretty much spot on, usually a little bit less than the spec (like 96-97mA in this case). I would say if it's more than a couple of mA higher, there is a potential problem. As for WFGUI, it is only for Windows, but I suppose you can use a virtual machine with Windows on Mac as well. The bigger problem is to have a line in input, otherwise an external sound card is needed. For reference, D6C should have a 0.04% WRMS wow&flutter, so half of a DD. The difference should be visible on the oscilloscope, although I would not take that as a reference.
Good to hear about the washer, it was just too strange that they were missing on 2 different walkmans . Power draw is 99mA so it looks ok. I will use a VM for WFGUI, I have a soundcard so that should not be an issue.
