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In the Forum: Analog Playback
In the Thread: Copper Mat on a Micro Seiki Gun Metal Platter
Post Subject: SchematicPosted by Wellington on: 9/16/2017
Measet, I will try to find a photo and the schematic as you requested, but it may be a while before I can locate them. Plus, we are still digging out from Hurricane Irma down here. As I recall, I beefed up the raw D.C. supply and then used an LM317 regulator circuit. I attached the TO-220 regulator package using an existing hole inside the RY-5500 chassis in a manner that took advantage of the heavy chassis as a heat sink. The other parts were shoe-horned tightly inside. The original D.C. supply that ran off 100 V AC was pretty wobbly. I monitored its voltage on an oscilloscope as I applied varying loads to the platter with my hand and I observed pretty large amounts of ripple. Apparently it was just adequate to the task. My new beefier raw supply runs directly off 120 V AC now and it is then regulated down to the same original D.C. voltage, but with almost no ripple and having very high line rejection. My mods worked without any issues whatsoever. Your line voltage is probably 230 V AC in Europe, so you may still need a step-down transfomer unless your '5000 is configured for that voltage. How is your RY-5500 rated on its label?
Which brings me to my next point. Your problems trying to use the HS-80 may indicate a weak or failed power supply inside your RY-5500. There are numerous electrolytic capacitors inside the RY-5500 that are now 30+ years old. I replaced every single electrolytic cap in my two Micro Seiki tables (5000 and 1500). I also have two superb Kyocera PL-910 tables which were made by Micro Seiki, and I replaced the supply caps in those as well. You might try replacing your electrolytic caps before doing anything else. See if that doesn't make your motor more stable. Even if it doesn't, the new caps are warranted preventatively and should be replaced anyway before modifying the supply. You don't need audio caps here. Just buy high quality caps from Panasonic or Nichicon. I try to always find caps with a 105 Celsius rating. The temperature never gets high in the RY-5500, but I believe the 105-Celsius-rated caps to be slightly more reliable, and they usually cost little more.Rerurn to Romy the Cat's Site