[Bill Noble[_2_]]

"
First, Im norwegian, pardon my english.
Like Joanas, i have a sad cartridge story involving a Clearaudio Aurum and
a
Thorens TD126MkIII
Last weekend I had some friends over, there were drinks... and I broke the
rule
I have about not playing LP's while partying. The next morning, well,
around
noon, I got into the living room and found my turntable still turning,
with
the cartridge well into the inner groove of Rush's Caress Of Steel..(yeah,
I
know..)
There were foul language and gnashing of teeth.
After two days i finally had the guts to test the cartridge, and it seems
it
has survived! There is no lack in detail in high or low frequencies. How
is
this possible?
___________
Digiman

your english is excellent - pardon my lack of ability to speak any of the
Nordic languages....

you will do no damage to a stylus by letting it run in the end grooves of a
record for a very long time - the surface velocity is low, your tip is
diamond - don't worry about it. Damage occurs by dropping, bending, or
other physical abuse - the older all metal stylus or sapphire stylus might
actually wear out but as the advertizement says "diamonds are forever"
(well, nearly forever - I suppose if you let it run in the end groove for
ten or 20 years you could see wear on it)

let's try a calculation - 331/3 RPM, 4 inch diameter, so you travel 4 X pi X
331/3 X60 /12*5280 miles per hour - let's see (gets out calculator) - just
under four miles (or if you prefer, about 6 1/3 km) each hour. so in your
say 10 hours of not noticing while you slept, your stylus might have
traveled 40 miles or 63 km.

If you play one record, say 30 minutes on a side and the outer groove is 12
inches and the inner groove is 4 inches, we can pick an "average" diameter
of 8 inches and do the same calculation - conveniently 8 is twice 4, so your
one record goes about the same as one hour in the end groove - so the total
wear you put on your stylus is about the same as playing ten sides of a
typical LP.

so, don't worry, be happy.

[Digiman]

"Bill Noble" wrote in message
...
"
First, Im norwegian, pardon my english.
Like Joanas, i have a sad cartridge story involving a Clearaudio Aurum
and
a
Thorens TD126MkIII
Last weekend I had some friends over, there were drinks... and I broke
the
rule
I have about not playing LP's while partying. The next morning, well,
around
noon, I got into the living room and found my turntable still turning,
with
the cartridge well into the inner groove of Rush's Caress Of
Steel..(yeah,
I
know..)
There were foul language and gnashing of teeth.
After two days i finally had the guts to test the cartridge, and it seems
it
has survived! There is no lack in detail in high or low frequencies. How
is
this possible?
___________
Digiman

your english is excellent - pardon my lack of ability to speak any of the
Nordic languages....

you will do no damage to a stylus by letting it run in the end grooves of
a
record for a very long time - the surface velocity is low, your tip is
diamond - don't worry about it. Damage occurs by dropping, bending, or
other physical abuse - the older all metal stylus or sapphire stylus might
actually wear out but as the advertizement says "diamonds are forever"
(well, nearly forever - I suppose if you let it run in the end groove for
ten or 20 years you could see wear on it)

let's try a calculation - 331/3 RPM, 4 inch diameter, so you travel 4 X pi
X
331/3 X60 /12*5280 miles per hour - let's see (gets out calculator) - just
under four miles (or if you prefer, about 6 1/3 km) each hour. so in your
say 10 hours of not noticing while you slept, your stylus might have
traveled 40 miles or 63 km.

If you play one record, say 30 minutes on a side and the outer groove is
12
inches and the inner groove is 4 inches, we can pick an "average" diameter
of 8 inches and do the same calculation - conveniently 8 is twice 4, so
your
one record goes about the same as one hour in the end groove - so the
total
wear you put on your stylus is about the same as playing ten sides of a
typical LP.

so, don't worry, be happy.


I appreciate all the insightfull answers, but I must mention that my main
concern
was the much debated friction heat. When going round in the same groove over
and over again, wont' there be a buildup of heat in that particular groove
that heats up the stylus and also the cartridge to way over normal
temperature?
___________
Digiman

[Sonnova]

On Sat, 13 Dec 2008 13:10:15 -0800, Digiman wrote
(in article ):

"Bill Noble" wrote in message
...
"
First, Im norwegian, pardon my english.
Like Joanas, i have a sad cartridge story involving a Clearaudio Aurum
and
a
Thorens TD126MkIII
Last weekend I had some friends over, there were drinks... and I broke
the
rule
I have about not playing LP's while partying. The next morning, well,
around
noon, I got into the living room and found my turntable still turning,
with
the cartridge well into the inner groove of Rush's Caress Of
Steel..(yeah,
I
know..)
There were foul language and gnashing of teeth.
After two days i finally had the guts to test the cartridge, and it seems
it
has survived! There is no lack in detail in high or low frequencies. How
is
this possible?
___________
Digiman

your english is excellent - pardon my lack of ability to speak any of the
Nordic languages....

you will do no damage to a stylus by letting it run in the end grooves of
a
record for a very long time - the surface velocity is low, your tip is
diamond - don't worry about it. Damage occurs by dropping, bending, or
other physical abuse - the older all metal stylus or sapphire stylus might
actually wear out but as the advertizement says "diamonds are forever"
(well, nearly forever - I suppose if you let it run in the end groove for
ten or 20 years you could see wear on it)

let's try a calculation - 331/3 RPM, 4 inch diameter, so you travel 4 X pi
X
331/3 X60 /12*5280 miles per hour - let's see (gets out calculator) - just
under four miles (or if you prefer, about 6 1/3 km) each hour. so in your
say 10 hours of not noticing while you slept, your stylus might have
traveled 40 miles or 63 km.

If you play one record, say 30 minutes on a side and the outer groove is
12
inches and the inner groove is 4 inches, we can pick an "average" diameter
of 8 inches and do the same calculation - conveniently 8 is twice 4, so
your
one record goes about the same as one hour in the end groove - so the
total
wear you put on your stylus is about the same as playing ten sides of a
typical LP.

so, don't worry, be happy.


I appreciate all the insightfull answers, but I must mention that my main
concern
was the much debated friction heat. When going round in the same groove over
and over again, wont' there be a buildup of heat in that particular groove
that heats up the stylus and also the cartridge to way over normal
temperature?
___________
Digiman


I doubt it. Diamond is not a great conductor of heat and it dissipates
rapidly through the vinyl anyway. One might see some physical groove
distortion, but since there's no information in a lead-out groove anyway, who
cares?

[Greg Wormald[_2_]]

In article , "Digiman"
wrote:
I appreciate all the insightfull answers, but I must mention that my main
concern
was the much debated friction heat. When going round in the same groove over
and over again, wont' there be a buildup of heat in that particular groove
that heats up the stylus and also the cartridge to way over normal
temperature?
___________
Digiman

While heat is certainly a real issue for the immediate surface of the
groove, the LP itself is pretty large, and a reasonable heat-sink. So
while the repeated playing of the lead-out track has probably stuffed
that track due to over-wear and the (debatable) problems with quickly
repeated playings, I wouldn't be worrying about the stylus or the
cartridge.

Greg

[[email protected]]

On Dec 13, 7:35 pm, Sonnova wrote:
On Sat, 13 Dec 2008 13:10:15 -0800, Digiman wrote
(in article ):
I appreciate all the insightfull answers, but I must
mention that my main concern was the much
debated friction heat. When going round in the
same groove over and over again, wont' there be
a buildup of heat in that particular groove that
heats up the stylus and also the cartridge to way
over normal temperature?
I doubt it. Diamond is not a great conductor of heat
and it dissipates rapidly through the vinyl anyway.

Uh, no, it is precisely the opposite.

Diamond, in fact, has an extraordinarily high thermal
conductivity, one of the highest of any known substances,
and vinyl is, being an insulator, not very good.

Diamond has a thermal conductivity of 1800 W/mK,
let's assume an aluminum cantilever, with aluminum
having a thermal conductivity of around 250 W/mK.

Compare that to the thermal conductivity of vinyl,
at 0.19 W/mK.

The diamond has nearly 10,000 times the thermal
conductivity of the vinyl in the record.

[Arny Krueger]

"Digiman" wrote in message

I appreciate all the insightfull answers, but I must
mention that my main concern
was the much debated friction heat.

The heat is there, but as those of us who know the facts say, there is no
heating of the entire stylus, just a some microscopic spots on the stylus.

When going round in
the same groove over and over again, wont' there be a
buildup of heat in that particular groove that heats up
the stylus and also the cartridge to way over normal
temperature?

No, the only thing affected are the microscopic contact areas.

Here are the relevant calculations:

Please check my work as I currently have a massive sinus infection and my
head hurts

From Barlow, “The limiting tracking weight of gramophone pickups for
negligible groove damage”, J. of Audio Eng. Soc. 1958, p.216

"A 0.5 mil tip presents a side contact area of 23.4 square microns."

A micron is the same as a micrometre, a unit of length in the metric system:
one millionth of a metre.

A mil is one thousandth of an inch.

A stylus tip might be 0.5 mil, or 0.5 thousandth of an inch.

An inch is about 1/39.4 of a meter

The difference of these two measures is about 12,500 : 1

Now, think of a solid copper ball that is 12,500 inches or about 100 feet in
diameter.

Think of the contact patch as being 25 square inches or an area about 5
inches by 5 inches.

OK, so now lets do a thought experiment. I have a solid copper ball (diamond
is very conductive of heat) that is 100 feet in diameter. I obtain two very
large propane blow torches and apply one to each side of the copper ball,
each heating 25 square inches (approximately 5" x 5") of the copper ball to
well over 500 degrees.

How hot does the entire 100 foot diameter copper ball get due to the two
propane torches?

Barely noticable. temperature change over-all. If the ball were in a vacuum
and dissipated no heat, we could probably calcuate its slow heating. But the
air will carry almost all of the heat away. And, our thought experiment
does not consider the cooling effects of the vinyl heat sink that is in
intimate contact with the heated patch.