Placing Project Debut III turntable on adjustable cones
 

Keith G wrote:
"Don Pearce" wrote in message
...

On 16 Jan 2007 17:03:42 -0800, "max graff" wrote:


Hi guys,

i was reading the following article -

http://gallery.audioreview.com/showp...5&limit=recent

someone on here suggests getting rid of the the stock feet of the debut
III with adjustable cones to improve sound quality.

I was wondering how would that affect sound quality? I have pretty
sturdy stand and tiled flooring so vibrations aren't much of a problem.

Any tips?


Yup. Start drinking decaf and take up gardening. It is all starting to
get to you - and not in a good way.




I'm with you on this one, Don.....


Err, how long ago was it that you were posting pictures of slabs of
stone under DD turntables and considering removing the plinths?

--
Nick

Placing Project Debut III turntable on adjustable cones
 

"Nick Gorham" wrote in message
. uk...
Keith G wrote:
"Don Pearce" wrote in message
...

On 16 Jan 2007 17:03:42 -0800, "max graff" wrote:


Hi guys,

i was reading the following article -

http://gallery.audioreview.com/showp...5&limit=recent

someone on here suggests getting rid of the the stock feet of the debut
III with adjustable cones to improve sound quality.

I was wondering how would that affect sound quality? I have pretty
sturdy stand and tiled flooring so vibrations aren't much of a problem.

Any tips?


Yup. Start drinking decaf and take up gardening. It is all starting to
get to you - and not in a good way.




I'm with you on this one, Don.....


Err, how long ago was it that you were posting pictures of slabs of stone
under DD turntables and considering removing the plinths?



Nothing to do with it - the OP has described the worst scenario I can think
of for a TT (irrespective of drive) - rigid rack on a tiled floor (****ed if
he lives near the Underground, a railway or a busy main road, I would have
thought??) without any mention of isolation of any other 'transmitted
vibration absorption' mechanism.

My setup is massy and fairly well isolated - quite the opposite of the OP's
and my experiments were merely to determine that, having coupled extra mass
to a lightweight deck (alters inertia and resonance characteristics), soft
feet versus 'hard point' contact like spikes (OK, sponges and wooden balls
in my case - but, hey, at my age what do you expect?) had little or no
audible effect on the sound - as you witnessed yourself...

(Like the bugs in cheese - if I can't see it or hear it and it doesn't give
me the trots, then I'm not bothered about it...!! ;-)

Placing Project Debut III turntable on adjustable cones
 

"Nick Gorham" wrote in message

Arny Krueger wrote:
"Nick Gorham" wrote in message
. uk



But to address your point, there
is more going on in the mechanics of a turntable than
just isolation. If the table needs compliant mounting to
avoid feedback, then thats fine use it. However if the
support is sufficiently isolated to avoid that, then
there can be advantages to increasing the effective mass
of the turntable by solid coupling, as this can reduce
the effect of motor induced vibration.


Here's a skill-testing question for you, Nick.

What are good ways to figure out which problem is most
important to a given vinyl rig?

One thought would be to compare recording of the output
of the table both in the sound field of the loudspeakers
and not.

One evaluates motor noise by listening, measuring or making a recording with
the motor turning and the stylus in a groove. The record need not be turning
(we are not evaluating platter bearing noise, for example). So slip off the
belt. The speakers should be well isolated from the player. IOW, listen with
headphones, and if measurements or a recording is used, simply disconnect
the speakers or otherwise turn them off.

One evaluates pickup of external vibration including feedback by similar
means. Only now the motor can be turned off.

If acoustic feedback is the issue, then turn up the gain slowly until a
steady tone is heard, and back off just a bit. Note how much gain it takes
to just barely sustain feedback. Make whatever changes you wish, and see if
the gain before feedback can be increased.

If vibration sensitivity is the issue, then devise a means for producing a
consistant source of vibration. I have evaluated resistance to footfalls by
pushing a padded weight off of a chair onto the floor. This can be a fairly
consistent kind of stimulus. Be careful to not inadevertantly mix a test of
resistance to feedback into the test.



But that isn't comparing the effect of reducing
the mass.



I guess, you would have to make four
recordings, and decide which of them was prefered.

Placing Project Debut III turntable on adjustable cones
 

Arny Krueger wrote:
"Nick Gorham" wrote in message


Arny Krueger wrote:

"Nick Gorham" wrote in message
et.uk




But to address your point, there
is more going on in the mechanics of a turntable than
just isolation. If the table needs compliant mounting to
avoid feedback, then thats fine use it. However if the
support is sufficiently isolated to avoid that, then
there can be advantages to increasing the effective mass
of the turntable by solid coupling, as this can reduce
the effect of motor induced vibration.


Here's a skill-testing question for you, Nick.

What are good ways to figure out which problem is most
important to a given vinyl rig?


One thought would be to compare recording of the output
of the table both in the sound field of the loudspeakers
and not.


One evaluates motor noise by listening, measuring or making a recording with
the motor turning and the stylus in a groove. The record need not be turning
(we are not evaluating platter bearing noise, for example). So slip off the
belt. The speakers should be well isolated from the player. IOW, listen with
headphones, and if measurements or a recording is used, simply disconnect
the speakers or otherwise turn them off.

Ok, but what about motor noise that is transmitted via the belt? or
(shock horror) there isn't a belt? :-)

--
Nick

Placing Project Debut III turntable on adjustable cones
 

Arny Krueger wrote:
"Nick Gorham" wrote in message

Arny Krueger wrote:
"Nick Gorham" wrote in message
. uk



But to address your point, there
is more going on in the mechanics of a turntable than
just isolation. If the table needs compliant mounting to
avoid feedback, then thats fine use it. However if the
support is sufficiently isolated to avoid that, then
there can be advantages to increasing the effective mass
of the turntable by solid coupling, as this can reduce
the effect of motor induced vibration.

Here's a skill-testing question for you, Nick.

What are good ways to figure out which problem is most
important to a given vinyl rig?

One thought would be to compare recording of the output
of the table both in the sound field of the loudspeakers
and not.

One evaluates motor noise by listening, measuring or making a recording with
the motor turning and the stylus in a groove. The record need not be turning
(we are not evaluating platter bearing noise, for example). So slip off the
belt. The speakers should be well isolated from the player. IOW, listen with
headphones, and if measurements or a recording is used, simply disconnect
the speakers or otherwise turn them off.


And/or couple the stylus to the plinth by resting it on a block of wood
(for example) - a useful estimate of mechanical noise from non-suspended
decks in particular.

Placing Project Debut III turntable on adjustable cones
 

"Nick Gorham" wrote in message
. uk
Arny Krueger wrote:
"Nick Gorham" wrote in message


Arny Krueger wrote:

"Nick Gorham" wrote in message
. uk




But to address your point, there
is more going on in the mechanics of a turntable than
just isolation. If the table needs compliant mounting
to avoid feedback, then thats fine use it. However if
the support is sufficiently isolated to avoid that,
then there can be advantages to increasing the
effective mass of the turntable by solid coupling, as
this can reduce the effect of motor induced vibration.


Here's a skill-testing question for you, Nick.

What are good ways to figure out which problem is most
important to a given vinyl rig?


One thought would be to compare recording of the output
of the table both in the sound field of the loudspeakers
and not.


One evaluates motor noise by listening, measuring or
making a recording with the motor turning and the stylus
in a groove. The record need not be turning (we are not
evaluating platter bearing noise, for example). So slip
off the belt. The speakers should be well isolated from
the player. IOW, listen with headphones, and if
measurements or a recording is used, simply disconnect
the speakers or otherwise turn them off.

Ok, but what about motor noise that is transmitted via
the belt?

Rarely an issue. That's one of the benefits of belts - they act like a giant
low pass filter.

or (shock horror) there isn't a belt? :-)

Generalized plan B - use a test record and live with all of the noises and
vibrations are part of your measurement.