Oracle 1 Turntable Running Very Slow No Change In Speed In 45 or 33

[Fuzz1y1970]

Hi All, I have an Oracle 1 turntable, serial # 3954. It is running very slow and there is no change between 33 & 45 when I press the speed control buttons, in the front. The motor seems weak, the RPM seems consistent, no fluctuation? I'm pretty mechanical, any suggestions where to look/start? Thank you in advance for your suggestions.

 

[vinylkid58]

A Delphi mk1? Does it have an AC-DC power supply for the motor? If it does, I would check the output voltage with a MM.

jeff

 

[Fuzz1y1970]

Hi Jeff, I plugged a 24 volt Dc transformer, I got from and old school electronics supply (they know there stuff) and no change. Then I plugged in nan Oracle 27 volt DC transformer, I had floating around and still no change? I used a new belt and the table turns freely. 33 1/3 and 45 RPM, not change?

Sheldon

 

[ripblade]

Have you checked the speed adjuster pots in the back of the motor case? If turning these has no effect and the DC supplies are ok then the problem will be with the motor drive board inside the motor housing. Mine had cold solder joints on the pass transistors which luckily were accessible without removing the cover. If the entire board needs servicing, then the pulley has to be pulled before opening the case to access the board.

FIY, my wall wart needed new caps and the Dynamic Isolator had to be rebuilt from scratch. These are over 40 yo now so servicing is due.

 

[Fuzz1y1970]

I just ordered and RPM meter and will see where it lands? More to follow!

 

[Montycat]

Oracle is still around and provides good support for legacy models. Don't be shy about contacting them for help.