Michell Gyro Se running a little slow

Thinking that your turntable runs slow is one thing. Actually running slow is another. Use an inexpensive strobe to determine if it is, in fact, slow. Many other components have an effect on PRaT which can give the impression of slow speed. Then again, if you are blessed/cursed with perfect pitch, you can pretty much be assured that it is running slow.

The bearing and well are key to keeping the unit from running slow. The michell gyro inverted bearing has a pumping system that moves oil up tothe bearing. low oil or dirty oil can cause issues The other possibility is the bearing is bad. It is unlikely, but I have seen that once on my michell.

I checked the oil first thing so I don't think that is the issue. I actually filled the oil well a little while ago. I'll check the bearing to see if that is the problem and get a strobe as well. Viridian, what can I check on my other components to see if the problem is elsewhere.

Check to see that the main screw under the spindle is tight. If not fully tightened at installation it can become loose resulting in a lower speed. Had this problem some time back. Need a coin to fully tighten it.
NJoy

Get the KAB speedstrobe or another strobe and check the speed. Since you have the HR Power supply it's easy enough to adjust it. My Gyrodec was running about 1% fast prior to adjustment. But I never had a wow-flutter problem.

So, as has been mentioned:
--Make sure bearing is lubed and clean
--Clean your belt
--Clean the pulley an the groove on the platter
--check speed with strobe (you can also use a generic strobe disk from Vinyl Engine, with an incandescent light. Just not as accurate and a little hard to see)
--Try with the standard power supply to see if you have the same problem/issue
--Grab a piano album and make sure the notes don't sound 'sour' or vary during sustained notes