The mythology that direct drive turntables are inherently
prone to problems with "cogging" is much more about
perception than fact. It is largely based on the myth that a
rubber belt does a superior job of reducing speed
variations.

Some misapprehensions about so-called direct drive
turntables trace back to the terminology "Direct Drive". A
more detailed understanding of how direct drive turntables
work reveals that the so-called direct drive turntable's
platter is not driven directly, but that the rotational
drive is applied through a varying magnetic field. This
magnetic field replaces the traditional rubber belt or wheel
as the flexible means by which the turntable is driven.

Two disadvantages of drive through rubber belts or wheels is
that the compliance, stiffness or flexibility of a rubber
wheel or belt is constant in the short term, and degrades
over the long term as the elastic parts wear and/or stiffen.

Rubber and other elastomers tend to harden over time, and
crack finally demanding replacement. In contrast, magnetic
fields are constantly being replenished by the control
system, and do not themselves necessarily degrade over time
like flexible belts and wheels.

The stiffness of a turntable's drive relates to how well the
rotating mass of the platter filters out speed variations. A
drive that is less stiff leads to better filtration. A
highly flexible drive can be traded off with the mass of the
turntable. The filtering action is based on the combination
of a high-mass platter and a highly flexible drive. If you
increase the mass and stiffen the drive the filtering action
remains constant. If you make the drive more flexible or
increase the mass, the filtering action improves.

However, it is not practical to make a turntable with an
extremely flexible belt or wheel drive because it would take
forever to come up to speed. Ideally, we'd like to have a
belt that is stiff for fast starts, and highly flexible for
smooth running. But rubber belts and wheels can't adapt to
changing needs. They are what they are that day.

A major highly desirable property of a direct drive
turntables' magnetic field drive is that the stiffness of
the drive can be varied rapidly by its electronic control
system. This contrasts with a rubber wheel or belt whose
stiffness remains the same as you start, run and stop the
turntable. A rubber belt's stiffness must be compromised
because it can't adapt to changing needs. The stiffness of a
magnetic drive can change rapidly and automatically to meet
changing needs.

A magnetic field drive based on an internal speed sensor
naturally simulates a stiff belt when the turntable is
starting up, and then automatically and naturally changes
over to something like a very stretchy rubber belt, when the
turntable is running normally.

If you use your finger to drag a direct drive turntable to a
stop, you may feel the control system pushing harder,
perhaps even pulsing. This does not mean that it is pulsing
significantly when the turntable is running normally.

The measure of the constant speed of a turntable should be
reliably determined by bias-controlled listening tests and
standard technical measures for speed consistency, not
behavior under unusual operating conditions.

There's no doubt that el-cheapo direct turntables that have
problems with speed control have made their way onto the
market. However, the basic direct drive technology has far
greater potential to provide excellent, long-lasting high
performance than a belt drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a testimonial
to the failure of high end manufacturers and publications to
properly educate their public.

"Arny Krueger" wrote in message
...
The mythology that direct drive turntables are inherently prone to
problems with "cogging" is much more about perception than fact. It is
largely based on the myth that a rubber belt does a superior job of
reducing speed variations.

Some misapprehensions about so-called direct drive turntables trace back
to the terminology "Direct Drive". A more detailed understanding of how
direct drive turntables work reveals that the so-called direct drive
turntable's platter is not driven directly, but that the rotational drive
is applied through a varying magnetic field. This magnetic field replaces
the traditional rubber belt or wheel as the flexible means by which the
turntable is driven.

Crugly spoken, but partially true.
There are details associated with each method that also have a bearing
[sic].

Recently, I asked Arny to clarify about what he calls "magnetic coupling",
and he responded, as usual, with a gratuitous insult. Here he has
inadvertently answered the question, making it clear that he is referring to
the magnetic field inside the motor.

That a driving magnetic field does not provide acoustic isolation is easily
demonstrated in one device with which we are all familiar, namely, the
dynamic loudspeaker. Whether the field in a motor creates a disturbance
audible at the stylus is a function of driving method. Pulse modulation of
the motor drive has a minimum power, depending upon the circuitry used. No
motor can function at zero drive. Therefore, some modulation is always
present at the driving frequency. Certain geometric/phase arrangments
produce constant driving torque, but there is a 2nd order effect that works
against this. Any variation in the motor from completely symmetric internal
geometry will cause a cyclic variation in torque. Any winding variation, or
asymmetry of the driving circuitry, will cause a cyclic torque.

These are potential problems with the direct drive arrangement. The belt
drive virtually guarantees that rotational defects will be limited to low
frequency artifacts. Belt drive permits optimization of the platter support,
in the form of simplified bearings, less likely to cause mechanical noise
than the ball or fluid dynamic bearings used in motors. All bearings have,
by their nature, a minimum clearance, which permits a disturbance in motor
geometry, as described above.

These are potential pitfalls. I do not mean to say that either type of
implementation is invariably superior. But since one cannot be guided, by
the type, to the superior choice, the actual performance of the turntable
must be evaluated by testing. I would suggest it's pointless for rao'ers to
beat each other over the head regarding the internals, as opposed to the
result.

"Arny Krueger" wrote in message
...
The mythology that direct drive turntables are inherently prone to
problems with "cogging" is much more about perception than fact. It is
largely based on the myth that a rubber belt does a superior job of
reducing speed variations.

Some misapprehensions about so-called direct drive turntables trace back
to the terminology "Direct Drive". A more detailed understanding of how
direct drive turntables work reveals that the so-called direct drive
turntable's platter is not driven directly, but that the rotational drive
is applied through a varying magnetic field. This magnetic field replaces
the traditional rubber belt or wheel as the flexible means by which the
turntable is driven.

Two disadvantages of drive through rubber belts or wheels is that the
compliance, stiffness or flexibility of a rubber wheel or belt is constant
in the short term, and degrades over the long term as the elastic parts
wear and/or stiffen.

Rubber and other elastomers tend to harden over time, and crack finally
demanding replacement. In contrast, magnetic fields are constantly being
replenished by the control system, and do not themselves necessarily
degrade over time like flexible belts and wheels.

The stiffness of a turntable's drive relates to how well the rotating mass
of the platter filters out speed variations. A drive that is less stiff
leads to better filtration. A highly flexible drive can be traded off with
the mass of the turntable. The filtering action is based on the
combination of a high-mass platter and a highly flexible drive. If you
increase the mass and stiffen the drive the filtering action remains
constant. If you make the drive more flexible or increase the mass, the
filtering action improves.

However, it is not practical to make a turntable with an extremely
flexible belt or wheel drive because it would take forever to come up to
speed. Ideally, we'd like to have a belt that is stiff for fast starts,
and highly flexible for smooth running. But rubber belts and wheels can't
adapt to changing needs. They are what they are that day.

A major highly desirable property of a direct drive turntables' magnetic
field drive is that the stiffness of the drive can be varied rapidly by
its electronic control system. This contrasts with a rubber wheel or belt
whose stiffness remains the same as you start, run and stop the turntable.
A rubber belt's stiffness must be compromised because it can't adapt to
changing needs. The stiffness of a magnetic drive can change rapidly and
automatically to meet changing needs.

A magnetic field drive based on an internal speed sensor naturally
simulates a stiff belt when the turntable is starting up, and then
automatically and naturally changes over to something like a very stretchy
rubber belt, when the turntable is running normally.

If you use your finger to drag a direct drive turntable to a stop, you may
feel the control system pushing harder, perhaps even pulsing. This does
not mean that it is pulsing significantly when the turntable is running
normally.

The measure of the constant speed of a turntable should be reliably
determined by bias-controlled listening tests and standard technical
measures for speed consistency, not behavior under unusual operating
conditions.

There's no doubt that el-cheapo direct turntables that have problems with
speed control have made their way onto the market. However, the basic
direct drive technology has far greater potential to provide excellent,
long-lasting high performance than a belt drive.

That these myths about turntable drive systems have persisted so long and
remain so wide spread is a testimonial to the failure of high end
manufacturers and publications to properly educate their public.


Way to far over the heads of the faithful. :-)

In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that have
problems with speed control have made their way onto the
market. However, the basic direct drive technology has far
greater potential to provide excellent, long-lasting high
performance than a belt drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a testimonial
to the failure of high end manufacturers and publications to
properly educate their public.

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

Stephen

"Robert Morein" wrote in message


That a driving magnetic field does not provide acoustic
isolation is easily demonstrated in one device with which
we are all familiar, namely, the dynamic loudspeaker.

As usual Morein is working overtime trying to create new
fallacies as quickly as I spike the old ones.

Here Morein purpounds the fallacy that all magnetic fields
are the same. In fact they differ in a number of areas, most
significantly being strength.

Whether the field in a motor creates a disturbance
audible at the stylus is a function of driving method.

This statement ignores the fact that many system parameters
are more important than the driving method.

For example, the driving method in any modern turntable is
identically the same - a magnetic field in an electric
motor. It's the differences in the other system parameters
that makes a belt drive system different from a so-called
direct drive system.

Pulse modulation of the motor drive has a minimum power,
depending upon the circuitry used.

In fact pulse modulation is used on both direct drive and
also some belt drive turntables. Therefore the introduction
of pulse modulation is a straw man argument and can be
safely ignored.

No motor can function at zero drive.

I never said that they did. So this would be the second
straw man argument in the same paragraph.

Therefore, some modulation is always
present at the driving frequency.

Here the classic error of ignoring quantification is made.

Certain geometric/phase
arrangments produce constant driving torque, but there is
a 2nd order effect that works against this.

Again this applies to both belt drives and so-called direct
drives so we now have our third straw man argument.

Any variation
in the motor from completely symmetric internal geometry
will cause a cyclic variation in torque. Any winding
variation, or asymmetry of the driving circuitry, will
cause a cyclic torque.

This again applies to both belt drives and so-called direct
drives so we now have our fourth straw man argument.


These are potential problems with the direct drive
arrangement.

Every problem listed so far applies to both belt drive and
direct drive systems.

The belt drive virtually guarantees that
rotational defects will be limited to low frequency
artifacts.

The presence of a belt is not a panacea. The time-honored
open-loop motor driving a rubber belt suffers from a number
of problems related to operational parameters that can't
change when the operational mode changes from start-up to
normal rotation.

Belt drive permits optimization of the platter support,

Direct drive provides more options. Since direct-drive
motors run at a far slower speed than belt-drive motors,
natural vibration modes are not in the audio range. For
example a belt-drive motor might have 24 poles and turn at
300 rpm. This results in 7200 noise impulses per minute,
which corresponds to a noise at 120 Hz.


in the form of simplified bearings, less likely
to cause mechanical noise than the ball or fluid dynamic
bearings used in motors.

In fact platter bearings in direct drive turntables can be
identical to platter bearings in belt-drive turntables. This
comment by Morein is no doubt based on his inability to
actually examine a number of direct-drive turntables due to
his confinement.

All bearings have, by their
nature, a minimum clearance, which permits a disturbance
in motor geometry, as described above.

Just another item that is common to both direct-drive and
belt-drive designs. This makes Morein's fifth straw man
argument in just one post.

These are potential pitfalls. I do not mean to say that
either type of implementation is invariably superior. But
since one cannot be guided, by the type, to the superior
choice, the actual performance of the turntable must be
evaluated by testing. I would suggest it's pointless for
rao'ers to beat each other over the head regarding the
internals, as opposed to the result.

Notice that my post mentioned no names, so there was no
"beating" involved. OTOH, Morein gratuitously mentioned my
name in a negative context that went well beyond simply
quoting my post. I think that Morien's bad faith should be
obvious to all.

wrote in message
nk.net
"Arny Krueger" wrote in message
...
The mythology that direct drive turntables are
inherently prone to problems with "cogging" is much more
about perception than fact. It is largely based on the
myth that a rubber belt does a superior job of reducing
speed variations. Some misapprehensions about so-called
direct drive
turntables trace back to the terminology "Direct Drive".
A more detailed understanding of how direct drive
turntables work reveals that the so-called direct drive
turntable's platter is not driven directly, but that the
rotational drive is applied through a varying magnetic
field. This magnetic field replaces the traditional
rubber belt or wheel as the flexible means by which the
turntable is driven. Two disadvantages of drive through
rubber belts or
wheels is that the compliance, stiffness or flexibility
of a rubber wheel or belt is constant in the short term,
and degrades over the long term as the elastic parts
wear and/or stiffen. Rubber and other elastomers tend to
harden over time,
and crack finally demanding replacement. In contrast,
magnetic fields are constantly being replenished by the
control system, and do not themselves necessarily
degrade over time like flexible belts and wheels. The
stiffness of a turntable's drive relates to how well
the rotating mass of the platter filters out speed
variations. A drive that is less stiff leads to better
filtration. A highly flexible drive can be traded off
with the mass of the turntable. The filtering action is
based on the combination of a high-mass platter and a
highly flexible drive. If you increase the mass and
stiffen the drive the filtering action remains constant.
If you make the drive more flexible or increase the
mass, the filtering action improves. However, it is not
practical to make a turntable with an
extremely flexible belt or wheel drive because it would
take forever to come up to speed. Ideally, we'd like to
have a belt that is stiff for fast starts, and highly
flexible for smooth running. But rubber belts and wheels
can't adapt to changing needs. They are what they are
that day. A major highly desirable property of a direct
drive
turntables' magnetic field drive is that the stiffness
of the drive can be varied rapidly by its electronic
control system. This contrasts with a rubber wheel or
belt whose stiffness remains the same as you start, run
and stop the turntable. A rubber belt's stiffness must
be compromised because it can't adapt to changing needs.
The stiffness of a magnetic drive can change rapidly and
automatically to meet changing needs. A magnetic field
drive based on an internal speed sensor
naturally simulates a stiff belt when the turntable is
starting up, and then automatically and naturally
changes over to something like a very stretchy rubber
belt, when the turntable is running normally. If you use
your finger to drag a direct drive turntable
to a stop, you may feel the control system pushing
harder, perhaps even pulsing. This does not mean that it
is pulsing significantly when the turntable is running
normally. The measure of the constant speed of a
turntable should
be reliably determined by bias-controlled listening
tests and standard technical measures for speed
consistency, not behavior under unusual operating
conditions. There's no doubt that el-cheapo direct
turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive. That these myths about turntable drive systems
have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers and
publications to properly educate their public.
Way to far over the heads of the faithful. :-)

Morein has already demonstrated that, and again showed bad
faith by gratuitous inclusion of a personal attack on me.
His continuted devotion to the debating trade was shown by
no less than 5 straw man arguments.

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers and
publications to properly educate their public.

Do you think audiophiles should abandon their highly
functional belt-drives

If you don't think its broken, don't try to fix it.

because someone might someday
market a direct-drive that fulfills this potential?

Please explain why you think that this is so?

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


That a driving magnetic field does not provide acoustic
isolation is easily demonstrated in one device with which
we are all familiar, namely, the dynamic loudspeaker.

As usual Morein is working overtime trying to create new fallacies as
quickly as I spike the old ones.

Arny's reply is shallow, deceitful, and unworthy of reply.

"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


That a driving magnetic field does not provide acoustic
isolation is easily demonstrated in one device with
which we are all familiar, namely, the dynamic
loudspeaker.

As usual Morein is working overtime trying to create new
fallacies as quickly as I spike the old ones.

Arny's reply is shallow, deceitful, and unworthy of reply.

But Robert, being desperate to appear to have said something
with substance, posted a reply anyway. It was even more
lacking in substance than the first . :-(

"MINe 109" wrote in message
...
In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that have
problems with speed control have made their way onto the
market. However, the basic direct drive technology has far
greater potential to provide excellent, long-lasting high
performance than a belt drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a testimonial
to the failure of high end manufacturers and publications to
properly educate their public.

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

Stephen

Don't expect an answer.
Arny's brain just received the order "Take evasive action!"

"Robert Morein" wrote in message

"MINe 109" wrote in message
...
In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive. That these myths about turntable drive systems
have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers
and publications to properly educate their public.

Do you think audiophiles should abandon their highly
functional belt-drives because someone might someday
market a direct-drive that fulfills this potential?

Stephen

Don't expect an answer.
Arny's brain just received the order "Take evasive

Robert, I cleverly posted an answer 8 minutes before you
made this post. Let's hear it for the usual time delays in
Usenet and your ignorance of them.
action!"

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


That a driving magnetic field does not provide acoustic
isolation is easily demonstrated in one device with
which we are all familiar, namely, the dynamic
loudspeaker.

As usual Morein is working overtime trying to create new
fallacies as quickly as I spike the old ones.

Arny's reply is shallow, deceitful, and unworthy of reply.

But Robert, being desperate to appear to have said something with
substance, posted a reply anyway. It was even more lacking in substance
than the first . :-(
Alright, here's a reply.

You cannot PROVE that one type is better than the other. Either design can
be executed with a varying degree of precision and competence. All the
points that you mentioned, for a particular case, can be either correct or
incorrect. I think that as a designer, I would prefer to do a direct drive
design. But neither of us has the hands-on experience of the world's great
turntable makers. Therefore, a design can be judged only by the performance,
not the ingredients.

I am amazed that you rose to the effort you did to negate Bret's troll.
Bret's post was obviously a troll, because it was a sloppy job. I'm sure he
had a lot of fun doing it. But you, in all seriousness, put a lot of work
into your post, trying to nail down "facts" about these two approaches that
are not facts, but merely factors, that the designer has to deal with.

Factors add and multiply cumulatively in a design, frequently leading to
consequences that cannot be anticipated by examining them in isolation.

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"MINe 109" wrote in message
...
In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive. That these myths about turntable drive systems have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers
and publications to properly educate their public.

Do you think audiophiles should abandon their highly
functional belt-drives because someone might someday
market a direct-drive that fulfills this potential?

Stephen

Don't expect an answer.
Arny's brain just received the order "Take evasive

Robert, I cleverly posted an answer 8 minutes before you made this post.
Let's hear it for the usual time delays in Usenet and your ignorance of
them.
action!"

It was exactly what I anticipated -- an evasion.

MINe 109 wrote:
In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that have
problems with speed control have made their way onto the
market. However, the basic direct drive technology has far
greater potential to provide excellent, long-lasting high
performance than a belt drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a testimonial
to the failure of high end manufacturers and publications to
properly educate their public.

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

You imply there hasn't been plethora of DD turntables that already
fullfill this mark. I think both DD and belt drive technologies have
been able to push platter rumble and speed variations (wow and flutter)

well below record noise. DD has a couple advantages IMO. Its lower
maintenance than belt but more importantly has greater torque which
makes
it a lot easier to use a record brush to remove surface dust before
playing.

I wish someone could supply truly dust free record sleeves.
I had some VPI record protectors which are zip lock plastic bags but
getting the record into the barely large enough opening is a PITA.
They've become embrittled over time and I had to replace them. I
bought a bunch of rice paper sleeves and plastic lined sleeves in bulk
and both are pretty dusty. I can put a perfectly clean record into the
sleeve and pull it out immediately with a bit o dust on it. I hit
every record with a brush before playing and the DD tables make this
alot easier than my old AR-XA which had so little torque any pressure
from the brush brought the platter to a halt.

The other advantage is that 45 to 33 speed changes are a push of a
button. Most belts need at least a change of pulley position.

ScottW

"Arny Krueger" wrote in message
. ..
wrote in message
nk.net
"Arny Krueger" wrote in message
...
The mythology that direct drive turntables are
inherently prone to problems with "cogging" is much more
about perception than fact. It is largely based on the
myth that a rubber belt does a superior job of reducing
speed variations. Some misapprehensions about so-called direct drive
turntables trace back to the terminology "Direct Drive".
A more detailed understanding of how direct drive
turntables work reveals that the so-called direct drive
turntable's platter is not driven directly, but that the
rotational drive is applied through a varying magnetic
field. This magnetic field replaces the traditional
rubber belt or wheel as the flexible means by which the
turntable is driven. Two disadvantages of drive through rubber belts or
wheels is that the compliance, stiffness or flexibility
of a rubber wheel or belt is constant in the short term,
and degrades over the long term as the elastic parts
wear and/or stiffen. Rubber and other elastomers tend to harden over
time,
and crack finally demanding replacement. In contrast,
magnetic fields are constantly being replenished by the
control system, and do not themselves necessarily
degrade over time like flexible belts and wheels. The stiffness of a
turntable's drive relates to how well
the rotating mass of the platter filters out speed
variations. A drive that is less stiff leads to better
filtration. A highly flexible drive can be traded off
with the mass of the turntable. The filtering action is
based on the combination of a high-mass platter and a
highly flexible drive. If you increase the mass and
stiffen the drive the filtering action remains constant.
If you make the drive more flexible or increase the
mass, the filtering action improves. However, it is not practical to
make a turntable with an
extremely flexible belt or wheel drive because it would
take forever to come up to speed. Ideally, we'd like to
have a belt that is stiff for fast starts, and highly
flexible for smooth running. But rubber belts and wheels
can't adapt to changing needs. They are what they are
that day. A major highly desirable property of a direct drive
turntables' magnetic field drive is that the stiffness
of the drive can be varied rapidly by its electronic
control system. This contrasts with a rubber wheel or
belt whose stiffness remains the same as you start, run
and stop the turntable. A rubber belt's stiffness must
be compromised because it can't adapt to changing needs.
The stiffness of a magnetic drive can change rapidly and
automatically to meet changing needs. A magnetic field drive based on
an internal speed sensor
naturally simulates a stiff belt when the turntable is
starting up, and then automatically and naturally
changes over to something like a very stretchy rubber
belt, when the turntable is running normally. If you use your finger to
drag a direct drive turntable
to a stop, you may feel the control system pushing
harder, perhaps even pulsing. This does not mean that it
is pulsing significantly when the turntable is running
normally. The measure of the constant speed of a turntable should
be reliably determined by bias-controlled listening
tests and standard technical measures for speed
consistency, not behavior under unusual operating
conditions. There's no doubt that el-cheapo direct turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive. That these myths about turntable drive systems have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers and
publications to properly educate their public.
Way to far over the heads of the faithful. :-)

Morein has already demonstrated that, and again showed bad faith by
gratuitous inclusion of a personal attack on me. His continuted devotion
to the debating trade was shown by no less than 5 straw man arguments.

I killfiled him, his posts are almost always pointless and when he does try
to wax technical, he usually gets it wrong either by ignorance or
deleiberate distortion of the facts. He's a waste of time.

"MINe 109" wrote in message
...
In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that have
problems with speed control have made their way onto the
market. However, the basic direct drive technology has far
greater potential to provide excellent, long-lasting high
performance than a belt drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a testimonial
to the failure of high end manufacturers and publications to
properly educate their public.

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

I think that you should keep whatever functioning table you have until it no
longer reasonable to do so. When it comes time for a new table get a proper
Direct Drive.

"Robert Morein" wrote in message


You cannot PROVE that one type is better than the other.

Either can be well-executed or poorly executed. Either can
be good enough. However, direct drive has a lot of
real-world advantages:

(1) No belt to stretch, crack or fall off the pulley. I've
had all 3 nasties happen to me with one or the other of the
3 belt-drive turntables that I have owned.

(2) Quick start.

(3) While belt drive can be good enough, direct drive has
the greatest potential for ultimate performance for the
reasons I've now had to go over several times.

Either design can be executed with a varying degree of
precision and competence.

Dooh!

All the points that you
mentioned, for a particular case, can be either correct
or incorrect.

Dooh!

I think that as a designer, I would prefer
to do a direct drive design.

Robert, given your demonstrated engineering savvy, I concur.
Any semi-competent basement mechanic can make a workable
belt-drive turntable drive system. A direct drive system
requires competence with electronic control systems, for
example.

But neither of us has the
hands-on experience of the world's great turntable
makers.

Well there you go, Robert's sixth straw man of the day.

Therefore, a design can be judged only by the
performance, not the ingredients.

Well if you want it to be reliable and perform as well as
possible, then the choice is clear - drop your belts!

On Mon, 05 Dec 2005 16:45:48 GMT, wrote:

That these myths about turntable drive systems have persisted so long and
remain so wide spread is a testimonial to the failure of high end
manufacturers and publications to properly educate their public.


Way to far over the heads of the faithful. :-)

Which is why Arnold uses a 15+ year old belt-drive turntable, when he
could have gotten a new direct drive turntable for about the same
amount of money.

dave weil said:

Way to[sic] far over the heads of the faithful. :-)

Which is why Arnold uses a 15+ year old belt-drive turntable, when he
could have gotten a new direct drive turntable for about the same
amount of money.

If you could beg borrow, or, steal a clue Mr. Wiel then, you would know
there is a big difference between an audiophool and a Engineer. Its like
some audiophool who subscribe's to Stereopile would gladly pay 1000's of
dollar's for a turn table when, its an inferrier media anyway. Thanks Mr.
Wile for admitting you prefer an infeerior technology. LOL! ;-)

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


You cannot PROVE that one type is better than the other.

[snip]

Dooh!

[snip]
Dooh!

[snip]

Well if you want it to be reliable and perform as well as possible, then
the choice is clear - drop your belts!

Arny, do the world a favor. Keep your belt on tight.

"ScottW" wrote in message
ups.com...

MINe 109 wrote:
In article ,
[snip]
You imply there hasn't been plethora of DD turntables that already
fullfill this mark. I think both DD and belt drive technologies have
been able to push platter rumble and speed variations (wow and flutter)

well below record noise. DD has a couple advantages IMO. Its lower
maintenance than belt but more importantly has greater torque which
makes
it a lot easier to use a record brush to remove surface dust before
playing.

I wish someone could supply truly dust free record sleeves.
I had some VPI record protectors which are zip lock plastic bags but
getting the record into the barely large enough opening is a PITA.
They've become embrittled over time and I had to replace them. I
bought a bunch of rice paper sleeves and plastic lined sleeves in bulk
and both are pretty dusty. I can put a perfectly clean record into the
sleeve and pull it out immediately with a bit o dust on it. I hit
every record with a brush before playing and the DD tables make this
alot easier than my old AR-XA which had so little torque any pressure
from the brush brought the platter to a halt.

Compare to idler drive, with inherently high torque and fast start.

The other advantage is that 45 to 33 speed changes are a push of a
button. Most belts need at least a change of pulley position.

ScottW

Another advantage of idler drive turntables. Speed can be changed by a
simple mechanical switch, avoiding the overcomplex approach of the other two
designs. Additionally, idler designs driven by a synchronous motor are
inherently more reliable that electronic motors, all of which incorporate
tantalum capacitors, each of which has a failure rate of about 1% per year.

Arny Krueger wrote:
"Robert Morein" wrote in message


You cannot PROVE that one type is better than the other.

Either can be well-executed or poorly executed. Either can
be good enough. However, direct drive has a lot of
real-world advantages:

(1) No belt to stretch, crack or fall off the pulley. I've
had all 3 nasties happen to me with one or the other of the
3 belt-drive turntables that I have owned.

Belts are cheap. A new design might even use 0-rings or even mag tape
as a belt.

(2) Quick start.

Important, for DJs. That's why DJ tables are direct drive. Not so for
audiophiles.

(3) While belt drive can be good enough, direct drive has
the greatest potential for ultimate performance for the
reasons I've now had to go over several times.

Either design can be executed with a varying degree of
precision and competence.

Dooh!

All the points that you
mentioned, for a particular case, can be either correct
or incorrect.

Dooh!

I think that as a designer, I would prefer
to do a direct drive design.

Robert, given your demonstrated engineering savvy, I concur.
Any semi-competent basement mechanic can make a workable
belt-drive turntable drive system. A direct drive system
requires competence with electronic control systems, for
example.

Solutions a basement mechanic could build are intrinsically more
sustainable than those requiring substantial interdisciplinary
expertise.

Legend has it that B.D. Maule and Kelly Johnson were introduced at
some aviation function as "great airplane designers". Now B.D. was a
basement mechanic whose airplane was essentially a homebuilt Piper
Pacer. Johnson was polite, but later made a Bacall/Kidman-like remark
about the tube-and rag taildragger vendor to one of the Lockheed test
pilots (I think it was Salmon or LeVier). Whoever it was, told Johnson
that fifty years after the last Blackbird had made its final flight,
Maules would still be flying.

Good belt drive tables are at least as good as any direct drive table
and far cheaper to implement, and in practice are more likely to excel,
sonically, than direct drive. OTOH direct drive tables are more
satisfactory for DJing and "scratching". Just as a QSC PA amp will
never really sound better when connected to efficient speakers in a
house than a well-built tube amp, a Technics SL1200 will never equal a
Merrill-modified AR or the admittedly overpriced Linn for sonics.

In article et,
wrote:

"Arny Krueger" wrote in message
...
The mythology that direct drive turntables are inherently prone to
problems with "cogging" is much more about perception than fact. It is
largely based on the myth that a rubber belt does a superior job of
reducing speed variations.

Some misapprehensions about so-called direct drive turntables trace back
to the terminology "Direct Drive". A more detailed understanding of how
direct drive turntables work reveals that the so-called direct drive
turntable's platter is not driven directly, but that the rotational drive
is applied through a varying magnetic field. This magnetic field replaces
the traditional rubber belt or wheel as the flexible means by which the
turntable is driven.

Two disadvantages of drive through rubber belts or wheels is that the
compliance, stiffness or flexibility of a rubber wheel or belt is constant
in the short term, and degrades over the long term as the elastic parts
wear and/or stiffen.

Rubber and other elastomers tend to harden over time, and crack finally
demanding replacement. In contrast, magnetic fields are constantly being
replenished by the control system, and do not themselves necessarily
degrade over time like flexible belts and wheels.

The stiffness of a turntable's drive relates to how well the rotating mass
of the platter filters out speed variations. A drive that is less stiff
leads to better filtration. A highly flexible drive can be traded off with
the mass of the turntable. The filtering action is based on the
combination of a high-mass platter and a highly flexible drive. If you
increase the mass and stiffen the drive the filtering action remains
constant. If you make the drive more flexible or increase the mass, the
filtering action improves.

However, it is not practical to make a turntable with an extremely
flexible belt or wheel drive because it would take forever to come up to
speed. Ideally, we'd like to have a belt that is stiff for fast starts,
and highly flexible for smooth running. But rubber belts and wheels can't
adapt to changing needs. They are what they are that day.

A major highly desirable property of a direct drive turntables' magnetic
field drive is that the stiffness of the drive can be varied rapidly by
its electronic control system. This contrasts with a rubber wheel or belt
whose stiffness remains the same as you start, run and stop the turntable.
A rubber belt's stiffness must be compromised because it can't adapt to
changing needs. The stiffness of a magnetic drive can change rapidly and
automatically to meet changing needs.

A magnetic field drive based on an internal speed sensor naturally
simulates a stiff belt when the turntable is starting up, and then
automatically and naturally changes over to something like a very stretchy
rubber belt, when the turntable is running normally.

If you use your finger to drag a direct drive turntable to a stop, you may
feel the control system pushing harder, perhaps even pulsing. This does
not mean that it is pulsing significantly when the turntable is running
normally.

The measure of the constant speed of a turntable should be reliably
determined by bias-controlled listening tests and standard technical
measures for speed consistency, not behavior under unusual operating
conditions.

There's no doubt that el-cheapo direct turntables that have problems with
speed control have made their way onto the market. However, the basic
direct drive technology has far greater potential to provide excellent,
long-lasting high performance than a belt drive.

That these myths about turntable drive systems have persisted so long and
remain so wide spread is a testimonial to the failure of high end
manufacturers and publications to properly educate their public.


Way to far over the heads of the faithful. :-)

Kind of like spelling?

In article . com,
"ScottW" wrote:

MINe 109 wrote:
In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that have
problems with speed control have made their way onto the
market. However, the basic direct drive technology has far
greater potential to provide excellent, long-lasting high
performance than a belt drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a testimonial
to the failure of high end manufacturers and publications to
properly educate their public.

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

You imply there hasn't been plethora of DD turntables that already
fullfill this mark. I think both DD and belt drive technologies have
been able to push platter rumble and speed variations (wow and flutter)

well below record noise. DD has a couple advantages IMO. Its lower
maintenance than belt but more importantly has greater torque which
makes
it a lot easier to use a record brush to remove surface dust before
playing.

I sure have no trouble using a brush with my belt drive. And the
platter is up to speed in about 4 seconds.

I wish someone could supply truly dust free record sleeves.
I had some VPI record protectors which are zip lock plastic bags but
getting the record into the barely large enough opening is a PITA.
They've become embrittled over time and I had to replace them. I
bought a bunch of rice paper sleeves and plastic lined sleeves in bulk
and both are pretty dusty. I can put a perfectly clean record into the
sleeve and pull it out immediately with a bit o dust on it. I hit
every record with a brush before playing and the DD tables make this
alot easier than my old AR-XA which had so little torque any pressure
from the brush brought the platter to a halt.

The other advantage is that 45 to 33 speed changes are a push of a
button. Most belts need at least a change of pulley position.

ScottW

In article om,
"Bret Ludwig" wrote:

Arny Krueger wrote:
"Robert Morein" wrote in message


You cannot PROVE that one type is better than the other.

Either can be well-executed or poorly executed. Either can
be good enough. However, direct drive has a lot of
real-world advantages:

(1) No belt to stretch, crack or fall off the pulley. I've
had all 3 nasties happen to me with one or the other of the
3 belt-drive turntables that I have owned.

Belts are cheap. A new design might even use 0-rings or even mag tape
as a belt.

There is at least one present design that uses mag tape.

In article . com,
"ScottW" wrote:

MINe 109 wrote:
In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that have
problems with speed control have made their way onto the
market. However, the basic direct drive technology has far
greater potential to provide excellent, long-lasting high
performance than a belt drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a testimonial
to the failure of high end manufacturers and publications to
properly educate their public.

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

You imply there hasn't been plethora of DD turntables that already
fullfill this mark.

Rockport, a coupla Technics and Denons, but I think Arny set the bar
higher than the last two.


I think both DD and belt drive technologies have
been able to push platter rumble and speed variations (wow and flutter)

well below record noise. DD has a couple advantages IMO. Its lower
maintenance than belt but more importantly has greater torque which
makes
it a lot easier to use a record brush to remove surface dust before
playing.

Which is it: both types are functional or direct-drive has fulfilled its
"greater potential"?

I wish someone could supply truly dust free record sleeves.
I had some VPI record protectors which are zip lock plastic bags but
getting the record into the barely large enough opening is a PITA.
They've become embrittled over time and I had to replace them. I
bought a bunch of rice paper sleeves and plastic lined sleeves in bulk
and both are pretty dusty. I can put a perfectly clean record into the
sleeve and pull it out immediately with a bit o dust on it. I hit
every record with a brush before playing and the DD tables make this
alot easier than my old AR-XA which had so little torque any pressure
from the brush brought the platter to a halt.

Not to mention the cool retrograde mode.

The other advantage is that 45 to 33 speed changes are a push of a
button. Most belts need at least a change of pulley position.

Yep. I prefer separate decks for 45 and 33 in stereo and mono, and for
78 rpm. Well, I would...

Stephen

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers and
publications to properly educate their public.

Do you think audiophiles should abandon their highly
functional belt-drives

If you don't think its broken, don't try to fix it.

because someone might someday
market a direct-drive that fulfills this potential?

Please explain why you think that this is so?

Some myth-busting: direct-drive has greater potential, but there aren't
any products.

Stephen

"Bret Ludwig" wrote in message
ps.com...

Arny Krueger wrote:
"Robert Morein" wrote in message


You cannot PROVE that one type is better than the other.

Either can be well-executed or poorly executed. Either can
be good enough. However, direct drive has a lot of
real-world advantages:

(1) No belt to stretch, crack or fall off the pulley. I've
had all 3 nasties happen to me with one or the other of the
3 belt-drive turntables that I have owned.

Belts are cheap. A new design might even use 0-rings or even mag tape
as a belt.

(2) Quick start.

Important, for DJs. That's why DJ tables are direct drive. Not so for
audiophiles.

(3) While belt drive can be good enough, direct drive has
the greatest potential for ultimate performance for the
reasons I've now had to go over several times.

Either design can be executed with a varying degree of
precision and competence.

Dooh!

All the points that you
mentioned, for a particular case, can be either correct
or incorrect.

Dooh!

I think that as a designer, I would prefer
to do a direct drive design.

Robert, given your demonstrated engineering savvy, I concur.
Any semi-competent basement mechanic can make a workable
belt-drive turntable drive system. A direct drive system
requires competence with electronic control systems, for
example.

Solutions a basement mechanic could build are intrinsically more
sustainable than those requiring substantial interdisciplinary
expertise.

snip of irrelvant airplane stuff.

Good belt drive tables are at least as good as any direct drive table
and far cheaper to implement, and in practice are more likely to excel,
sonically, than direct drive.

The least speed deviation is from Direct drive turntables.

OTOH direct drive tables are more
satisfactory for DJing and "scratching".

They are more reliable, they don't require a belt replacement ever, when
done with a modicum of precision, they are easily better than belt drive
tables no matter what the mythology of the high end says.

Just as a QSC PA amp will
never really sound better when connected to efficient speakers in a
house than a well-built tube amp, a Technics SL1200 will never equal a
Merrill-modified AR or the admittedly overpriced Linn for sonics.

Just keep making it up as you go along.

If you ever find any actual evidence to prove any of your points we'll all
be surpised, instead you make sweeping statements that simply don't fit the
facts as known.

Just becuase you find somebody else who agrees with you doesn't make you
right.

If precision is what the LP lover wants the LP lover wants a direct drive
table.

"Bret Ludwig" wrote in message
ps.com...

Good belt drive tables are at least as good as any direct drive table
and far cheaper to implement,

Sure, rubber bands are cheap.

and in practice are more likely to excel,

Proof?

sonically, than direct drive.

I didn't think so.

OTOH direct drive tables are more
satisfactory for DJing and "scratching". Just as a QSC PA amp will
never really sound better when connected to efficient speakers in a
house than a well-built tube amp,

I don't suppose you even A/B'd the QSC against some other SS amp, or did
you?
And it's a certainty that you did no DBT to see if you really hear a
difference instead of working from your overactive imaginiation.

LOL. That's a prefernce but the fact is still that any decent and that's
most of them, SS amp can run circles around a tube amp in terms of accuracy.
If you want tube sound stick a 1 ohm resistor in line with the speakers.

a Technics SL1200 will never equal a
Merrill-modified AR or the admittedly overpriced Linn for sonics.

POut a decent arm on the Technics and a better bass and you have a turntable
that will be more accurate than any rubber band driven gizmo.

On Mon, 05 Dec 2005 18:54:25 GMT, wrote:

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

I think that you should keep whatever functioning table you have until it no
longer reasonable to do so. When it comes time for a new table get a proper
Direct Drive.

Or, heaven forbid, a CD player.

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers
and publications to properly educate their public.

Do you think audiophiles should abandon their highly
functional belt-drives

If you don't think its broken, don't try to fix it.

because someone might someday
market a direct-drive that fulfills this potential?

Please explain why you think that this is so?

Some myth-busting: direct-drive has greater potential,
but there aren't any products.

There aren't any direct-drive products?????

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables that
have problems with speed control have made their way
onto the market. However, the basic direct drive
technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers
and publications to properly educate their public.

Do you think audiophiles should abandon their highly
functional belt-drives

If you don't think its broken, don't try to fix it.

because someone might someday
market a direct-drive that fulfills this potential?

Please explain why you think that this is so?

Some myth-busting: direct-drive has greater potential,
but there aren't any products.

There aren't any direct-drive products?????

That "provide [more] excellent, long-lasting high performance than a
belt drive"?

Existing good direct-drives are roughly equivalent to good belt-drives.

Stephen

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

There's no doubt that el-cheapo direct turntables
that have problems with speed control have made
their way onto the market. However, the basic direct
drive technology has far greater potential to provide
excellent, long-lasting high performance than a belt
drive.

That these myths about turntable drive systems have
persisted so long and remain so wide spread is a
testimonial to the failure of high end manufacturers
and publications to properly educate their public.

Do you think audiophiles should abandon their highly
functional belt-drives

If you don't think its broken, don't try to fix it.

because someone might someday
market a direct-drive that fulfills this potential?

Please explain why you think that this is so?

Some myth-busting: direct-drive has greater potential,
but there aren't any products.

There aren't any direct-drive products?????

That "provide [more] excellent, long-lasting high
performance than a belt drive"?

The right ones do.

Existing good direct-drives are roughly equivalent to
good belt-drives.

Except for their obvious failings.

In article ,
"Arny Krueger" wrote:

That "provide [more] excellent, long-lasting high
performance than a belt drive"?

The right ones do.

There's the Rockport. What else do you have in mind?

Existing good direct-drives are roughly equivalent to
good belt-drives.

Except for their obvious failings.

Which are as theoretical as the "advantages" of direct-drive.

Stephen

"MINe 109" wrote in message

In article ,
"Arny Krueger" wrote:

That "provide [more] excellent, long-lasting high
performance than a belt drive"?

The right ones do.

There's the Rockport. What else do you have in mind?

How about that Rockport? Would it have superior performance
with idler or belt drive?

Existing good direct-drives are roughly equivalent to
good belt-drives.

Except for their obvious failings.

Which are as theoretical as the "advantages" of
direct-drive.

The advantages of direct drive are mainfest, not purely
theoretical.

Follow the logic - people who buy turntable are
retro-technology fanciers, traditionalists. Belt drive is
more traditional than direct drive. Therefore, other than
turntablist turntables, whose sales numerically dominate the
LP player marketplace, most turntables are highly
traditionalist, retro technology designs. IOW, belt drive.
It's all about perception amongst people who don't want
things to change from how they were in the 60s and 70s.

On Tue, 6 Dec 2005 11:51:12 -0500, "Arny Krueger"
wrote:

Existing good direct-drives are roughly equivalent to
good belt-drives.

Except for their obvious failings.

Which are as theoretical as the "advantages" of
direct-drive.

The advantages of direct drive are mainfest, not purely
theoretical.

Follow the logic - people who buy turntable are
retro-technology fanciers, traditionalists. Belt drive is
more traditional than direct drive. Therefore, other than
turntablist turntables, whose sales numerically dominate the
LP player marketplace, most turntables are highly
traditionalist, retro technology designs. IOW, belt drive.
It's all about perception amongst people who don't want
things to change from how they were in the 60s and 70s.

Follow THIS logic - you buy a 15 year-old belt drive turntable instead
of a new direct drive turntable that can be had for about the same
price. Therefore, you have now shown yourself to be a Luddite who
doesn't want things to change from how they were in the 60s and 70s.
IOW, you've just a base reftro-technology fancier.

Good for you, Arnold. You are making progess.

"paul packer" wrote in message
...
On Mon, 05 Dec 2005 18:54:25 GMT, wrote:

Do you think audiophiles should abandon their highly functional
belt-drives because someone might someday market a direct-drive that
fulfills this potential?

I think that you should keep whatever functioning table you have until it
no
longer reasonable to do so. When it comes time for a new table get a
proper
Direct Drive.

Or, heaven forbid, a CD player.

Only if you care about hearing the most accurate playback possible.

Arny Krueger wrote:
The mythology that direct drive turntables are inherently
prone to problems with "cogging" is much more about
perception than fact. It is largely based on the myth that a
rubber belt does a superior job of reducing speed
variations.


The only thing I think about with direct drives, is all the ones I ever
used had
poor mechanical isolation. Some were so poor, that I could hear myself
walk across the room. I went through at least two direct drives myself
in the late 70's.
The first one had this wonderfull add, about how good the construction
was, and the use of concrete (it was really plastic with some kind of
ingrdient). This was was
absolutly horrible, a BSR. My second direct drive was a Sony, a little
better.
My introduction to cheap DJ setups in the 80's showed the usage of some
cheap Technics
turntables. The belt drives had good isolation, but the direct drive
still had worse
isolation than the belt counterpart. Perhaps the direct drives had a
bad
rap due to cheapness of some units. I think the record should be placed
on a stationary
platter inside a vacuum, and a Laser can scan the record. There would
be no bearing noise, induced feedback , or resonance.

greg

wrote in message
oups.com
Arny Krueger wrote:
The mythology that direct drive turntables are inherently
prone to problems with "cogging" is much more about
perception than fact. It is largely based on the myth
that a rubber belt does a superior job of reducing speed
variations.


The only thing I think about with direct drives, is all
the ones I ever used had
poor mechanical isolation.

Highly isolated turntables incorporating direct drive have
been made.

This appears to be a good example of a highly isolated DD
turntable:

http://stereophile.com/turntables/258/

A lot of current DD models are DJ turntables, which tend to
be stiffly-sprung so that the LPs can be manipulated.

In article , "Arny Krueger" wrote:
wrote in message
roups.com
Arny Krueger wrote:
The mythology that direct drive turntables are inherently
prone to problems with "cogging" is much more about
perception than fact. It is largely based on the myth
that a rubber belt does a superior job of reducing speed
variations.


The only thing I think about with direct drives, is all
the ones I ever used had
poor mechanical isolation.

Highly isolated turntables incorporating direct drive have
been made.

This appears to be a good example of a highly isolated DD
turntable:

http://stereophile.com/turntables/258/

A lot of current DD models are DJ turntables, which tend to
be stiffly-sprung so that the LPs can be manipulated.

Some of the DJ stuff I saw in the 80's, the floors would jump, and the
turntables had to be special. I double isolated them. When I
first used a CD player, I had to physically hold the player, so it would not skip!

greg