bluesboy Posted December 28, 2022 Share Posted December 28, 2022 I have a Micro Seiki DD 40 turntable that seems to be having issues with the 45 RPM speed. I've looked at the motor to see if there is a way to lube it and the motor appears to be sealed. I couldn't see any way to open it. The 33 RPM works fine. Have any of you guys had any experience servicing one of these? 1 Quote Link to comment Share on other sites More sharing options...
MicroMara Posted December 28, 2022 Share Posted December 28, 2022 The turntable is driven by a DC servo motor with integrated tachogenerator which directly drives the turntable with the standard speeds 33 1/3 and 45 RPM . Obviously, the tachogenerator has to be readjusted to 45 RPM. You can open the motor unit from below as shown here,if you´re not experienced you better bring this wonderful TT to a technician to readjust the tachogenerator 1 Quote Link to comment Share on other sites More sharing options...
bluesboy Posted December 28, 2022 Author Share Posted December 28, 2022 Thanks for the info Micro. 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted December 28, 2022 Share Posted December 28, 2022 what is the issue with the 45 RPM , too fast , too slow , does not spin at all .....? Quote Link to comment Share on other sites More sharing options...
bluesboy Posted December 28, 2022 Author Share Posted December 28, 2022 There's been an issue for a while getting the strobe to stay still at 45 rpm. Now the speed is actually audibly slowing down while playing. Quote Link to comment Share on other sites More sharing options...
OO1 Posted December 29, 2022 Share Posted December 29, 2022 spray DeoxIT on the 45 RPM variable pitch potentiometer , turn the knob 20 times to loosen up the dirt.... oxidation on the wiper 1 Quote Link to comment Share on other sites More sharing options...
MicroMara Posted December 29, 2022 Share Posted December 29, 2022 @bluesboy don´t do anything with Dexoit , please follow my yesterdays recommondation , there is a variable resistor for the speed fine adjustment as shown below . I made a copy from the dd 40 service manual regarding your speed issue 2 Quote Link to comment Share on other sites More sharing options...
bluesboy Posted December 29, 2022 Author Share Posted December 29, 2022 Thanks Micro for taking the time to post this. I'll give this a try Saturday and let you know how it comes out. 1 1 Quote Link to comment Share on other sites More sharing options...
Blvdre Posted December 30, 2022 Share Posted December 30, 2022 If the speed is varying while playing (audibly slowing down), the pot's wiper or resistive element may be dirty. In MM's posted instructions above, I would add step 1.5: Run the adjustment for both 33 and 45 rpm back and forth, from end to end, several times. This will help clean the wiper and resistive track of dirt. Many potentiometers don't have a hard stop at the end of their adjustment, but will make a quiet click, so keep your ears open. 2 Quote Link to comment Share on other sites More sharing options...
bluesboy Posted January 4, 2023 Author Share Posted January 4, 2023 Success! Thanks guys for all the help on this. 45 RPM is now steady. I think Blvdre was right about there being crud on the wiper and resistive track. Thanks again to MicroMara for posting the adjustment instructions. 5 Quote Link to comment Share on other sites More sharing options...
MicroMara Posted January 4, 2023 Share Posted January 4, 2023 Glad to know that you´ve fixed it , well done ! 2 Quote Link to comment Share on other sites More sharing options...
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