Summer Makes My TT Slower?

[watchnerd]

My belt drive turntable is running about 1% slower in the summer than in the winter.

I don't think the belt can have worn that much in 6 months.

Could the warmer days and nights in the house in the summer have made the belt looser?

 

[Robin L]

My belt drive turntable is running about 1% slower in the summer than in the winter.

I don't think the belt can have worn that much in 6 months.

Could the warmer days and nights in the house in the summer have made the belt looser?

The pitch on my guitars heads south when things get warm. On the other hand, correlation is not causation. Frank Dernie [in his thread on his Goldmund turntable] notes that there's two different weights of oil for the tt, depending on weather conditions, the oil affects speed, apparently. And if there is some sort of speed control, that could have shifted for any number of reasons.

(1) As promised some Goldmund Reference photos from when I last serviced it. Too much tech alert! | Audio Science Review (ASR) Forum

 

[DVDdoug]

Do you know the speed is regulated? Is there a variable speed control? Synchronous motors (if they still use those?) are controlled by the power line frequency (which is usually darn-accurate in 1st-world countries). Quartz crystals are also usually accurate & stable, but if there is a variable analog speed control that circuit may not be so stable.

Belts usually last a long time. It's been LONG time since I had a belt-drive turntable (or a tape deck) but from what I remember, when they start slipping you get wow (speed variations) along with the overall slower speed.

 

[MaxBuck]

Check your household voltage. It drops in many areas in the summer because of increased demand on the grid. Lower voltage could lower motor speed.

 

[jsrtheta]

Check your household voltage. It drops in many areas in the summer because of increased demand on the grid. Lower voltage could lower motor speed.

That was my first guess, too.

 

[Inner Space]

Could the warmer days and nights in the house in the summer have made the belt looser?

Haven't you guys been having more than "warmer" up there? I imagine the voltage sag must be huge. Halfway to a brownout, surely. That would make anyone's TT run slow.

 

[MakeMineVinyl]

The problem can probably be narrowed down by considering what type of speed control the motor has. The viscosity of the oil changing in different seasons sounds reasonable too. Personally, I've used belts in my Thorens for over a decade with no change in performance or visible degradation.