Mechanic hum

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi

How can there be some scilent mechanical hum from my recordplayer when it´s not on. It´s a Thoréns TD-150 mk1.
I have done all kind of restoring, but not the electrical part.
There is just only one capacitor and one resistor and no transformer.
Please give me some advise.
An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.
 
Ragnwald said:
Hi

How can there be some scilent mechanical hum from my recordplayer when it´s not on. It´s a Thoréns TD-150 mk1.
I have done all kind of restoring, but not the electrical part.
There is just only one capacitor and one resistor and no transformer.
Please give me some advise.
An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

Can you draw a wiring circuit?
That 5,6K resistor is it paralleled to yellow cap? and both
are connected to the mechanical switch?
Try to change "polarity!!!" of the power cord in the wall socket!
This might help

:)
 
Can you try this?
Warning: :att'n:
This is under mains voltage 230Volts.
Before you try anything, pull out the power cord from the wall socket.
 

Attachments

  • untitled-1.gif
    untitled-1.gif
    25.2 KB · Views: 207
cbdb said:
sorry, misunderstood. does it vibrate when playing?


As the man said, it is vibrating when built in automatic switch turned off:D
I also hate any humming in my very silent room when the music stops.
BTW I never turn off my 2KW equipment when full loaded, the lights is light shows!:)
I think that easiest way to stop this is to remove 10 nf cap, or to put lower value like 2n2 cap. and try.
Without cap will cost some sparking in the switch contacts, and might some short pops in the speakers!!!
:) :) :)
 
cbdb

This player must be some 45 - 50 years old.
Here we have some quality piece to talk about. :yes:

But wat type of caps are best useful (modern caps) in these places, as we can see in my schematic?

Or is there a way to make the motorsupply even better, without change of the motor?
 
If that schematic of yours is correct - with the 10 nF across the switch- the motor WILL hum. 10 nF at 50 Hz is appx. 6.5 kohm - in series with the other 5.6 k. That cap is prob'ly OK.
I cannot see that cap in your photos either....
A cap across the switch in this fashion is typical for a noise killer, prob'ly should be an X1 type filter cap, but in this circuit it causes more trouble than it cures....did you put it there, or is it original?
 
X and Y caps are indeed for this purpose......
It's just that 10 nF in series with the 5,6k, or more correctly Xc of 6.4k in series with 5.6k......mmmm
Try to get hold of a new 10nF X-cap - or any other 10 nF 400V for a test....
I just remebered I changed one on my wife's Husquarna sewing machine- gone bad and connected across the pedal. When plugged in, the thing started on ints own after some 10 mins!
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.