"lordy" wrote in message
...
On 2006-08-29, lordy wrote:
On 2006-08-29, Keith G wrote:

"lordy" wrote


I did a bit of experimenting, I removed the belt,
the noise only occurs when the motor is on and the needle is either
in the groove, or outside the groove and not moving
tangentially/skating.



Presumably you have removed the transit screws from the motor.....????

Yup. Forgot to mention that. Yup. These have already been removed and
the motor is hanging freely on its elastic bands.

Its either electrical or somehow vibration is travelling through the
tonearm, as it was still audible when the record was lifted clear of the
platter.

Lordy

Hmmm,

Apart from two other chaps mentioning hum on avforums (One who may not
have earthed properly). It looks like this could be something more
widespread..

See customer comment here..
http://store.acousticsounds.com/brow...tion=equipment

But this could be a red herring on my part...

Lordy

Could be a bit of hum and rumble mixed in together. No I haven't bothered
placing your samples into CEP and analysing them - too busy today for that.
Some records actually have some rumble evident from the master cutting
process. :-(

To eliminate the 50Hz hum from the equation, set the turntable platter in
motion and lower the cartridge so that the stylus is just clearing the
record surface. Move the tonearm from the outer edge of the record towards
the label area. If there is any hum induction taking place it will be
clearly heard without the possibility of rumble pickup and record surface
noise masking the induced hum. Then experiment with potential earth loop
problems.

Worth a try. What have you got to lose?

Cheers,
Alan