Vintage HiFi Audio Forum

Repair / Help Forum => Repair / Help => Topic started by: christianjiudelawrence on July 05, 2022, 09:47:42 AM

Title: Amp picking up turntable motor
Post by: christianjiudelawrence on July 05, 2022, 09:47:42 AM

Hi all. Picked up this lovely Columbia 2190RM portable turntable (minus the lid) in a Japanese second hand store and it seems to be amplifying the noise of the motor. I'm guessing it's a grounding issue, but I'm not knowledgeable enough to solve it. Several cables go from the turntable and the amp's circuit board to ground. They seem intact to me. Any ideas? You can see a video here:

http://youtu.be/6264Gson-9w (http://youtu.be/6264Gson-9w)

<iframe width="560" height="315" src="http://www.youtube.com/embed/6264Gson-9w" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Title: Re: Amp picking up turntable motor
Post by: Sir Thrift-a-Lot on July 05, 2022, 03:54:15 PM

I think it's just physical vibration.   Ceramic carts tend to be very microphonic.   Is the rubber on the idler wheel supple or hard and brittle?   If it's very hard, that could be your biggest culprit.