Technics direct drive turntables
 

On Fri, 14 Jan 2011 12:18:19 -0000, Arny Krueger wrote:

"Bob Latham" wrote in message

In article ,
David Looser wrote:


Granted the devotees of the Linn go far more OTT than
you (the Linn isn't just a turntable, it's a magical
machine that turns any third-rate audio system into a
music machine to satsfy the gods, or so they tell me).

So sorry, simply better. :-)

Unfortunately, unquantifiably so in any technical sense.

The TD125 was a far better product.



I too believe this to be true. I acquired mine from a local Hi-Fi shop in
the late 70s as a motorboard kit (sans tone arm and plinth), electing to
make my own "Chinese Copy" of the original plinth as pictured in the HiFi
Year book of '75 using 1 cm thick perspex and fitting an SME2009 MK2 tone
arm fitted with an ADC XLM cartridge.

I still use it (off and on) today to digitise my modest collection of
vinyl. When I built the deck, I included a phono pre-amp to provide line
out levels and allow a headphone driver amp to be included. This makes it
a standalone music source in the same way that a tape deck provides an
already equalised line out source, neatly addressing the issues of noise
and hum loops (it just seemed stupid to connect the very weak cartridge
signals over an external cable run into the phono input on a seperate
amplifier box, after all, the same isn't done with the signals from a tape
replay head).

I've seen the (presumably later) TD160 model and its cost cutting plastic
platter hub which didn't impress me as being an improvement over the all
metal design of the TD125.

The only downside to belt drive is the durability of the belts themselves
but the one used in the thorens design seems to be made from very durable
materials and is still going strong after more than 30 years. I'm not sure
but I think I bought a replacement belt about ten years back as a
precaution. I might even have swapped the original out (but only to give
it a respite, not because it had failed or was causing trouble).

If I was to do one more "mod", it would be to provide a crystal
controlled 50Hz reference for the neon strobe. The mains source shows too
much short term drift for my liking.

--
Regards JB Good

Technics direct drive turntables
 

In article op.vqpwj2uikd9x7s@fred, Johny B Good
wrote:


I've seen the (presumably later) TD160 model and its cost cutting
plastic platter hub which didn't impress me as being an improvement
over the all metal design of the TD125.

Perhaps the 'plastic' has/had higher internal vibration loss, so might
reduce unwanted vibrations compared with the metal? No idea, never used or
examined either.


If I was to do one more "mod", it would be to provide a crystal
controlled 50Hz reference for the neon strobe. The mains source shows
too much short term drift for my liking.

How do you know its is the "mains" that is drifting and not what you are
comparing with?

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Technics direct drive turntables
 

On Fri, 11 Feb 2011 09:09:03 -0000, Jim Lesurf
wrote:

In article op.vqpwj2uikd9x7s@fred, Johny B Good
wrote:


I've seen the (presumably later) TD160 model and its cost cutting
plastic platter hub which didn't impress me as being an improvement
over the all metal design of the TD125.

Perhaps the 'plastic' has/had higher internal vibration loss, so might
reduce unwanted vibrations compared with the metal? No idea, never used
or
examined either.


If I was to do one more "mod", it would be to provide a crystal
controlled 50Hz reference for the neon strobe. The mains source shows
too much short term drift for my liking.

How do you know its is the "mains" that is drifting and not what you are
comparing with?

Slainte,

Jim


That's a good question Jim. I suppose I must have arrived at that
assumption simply because it mimicked the same flavour of drift as
displayed by the hum bar on a colour TV at "The End of The Broadcasting
Day"[1] before the transmitter was shutdown.

Of course, I'd have to actually do the mod before I could say with
absolute certainty that the variations were (almost) entirely due to the
mains alone.

[1] Ah, those were the days.

--
Regards JB Good

Technics direct drive turntables
 

In article op.vqqx05iukd9x7s@fred, Johny B Good
wrote:
On Fri, 11 Feb 2011 09:09:03 -0000, Jim Lesurf
wrote:


If I was to do one more "mod", it would be to provide a crystal
controlled 50Hz reference for the neon strobe. The mains source shows
too much short term drift for my liking.

How do you know its is the "mains" that is drifting and not what you
are comparing with?


That's a good question Jim. I suppose I must have arrived at that
assumption simply because it mimicked the same flavour of drift as
displayed by the hum bar on a colour TV at "The End of The Broadcasting
Day"[1] before the transmitter was shutdown.

The question occurred to me because your comment made me recall a
conversation with someone else years ago. He was using a 'direct drive' TT
whose strobe (so he told me) worked from the same clock as the actual TT,
yet showed variations in TT speed. Now, ignoring the distinction between
phase and frequency lock that struck me as a weird idea because if the
clock ran fast or slow you'd never know from the strobe display as the TT
would simply 'track the strobe'. :-)

Of course, I'd have to actually do the mod before I could say with
absolute certainty that the variations were (almost) entirely due to the
mains alone.

IIRC There is a webpage that shows the recent variations in UK mains
frequency. It is regularly updated and provided by the people who operate
the grid IIRC. You could use that to see if what you get with your TT
follows what it shows. Alas, I can't recall the URL, so you'd need to
search for it, or have someone else post the address.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Technics direct drive turntables
 

On Fri, 11 Feb 2011 16:51:18 +0000 (GMT), Jim Lesurf
wrote:

In article op.vqqx05iukd9x7s@fred, Johny B Good
wrote:
On Fri, 11 Feb 2011 09:09:03 -0000, Jim Lesurf
wrote:


If I was to do one more "mod", it would be to provide a crystal
controlled 50Hz reference for the neon strobe. The mains source shows
too much short term drift for my liking.

How do you know its is the "mains" that is drifting and not what you
are comparing with?


That's a good question Jim. I suppose I must have arrived at that
assumption simply because it mimicked the same flavour of drift as
displayed by the hum bar on a colour TV at "The End of The Broadcasting
Day"[1] before the transmitter was shutdown.

The question occurred to me because your comment made me recall a
conversation with someone else years ago. He was using a 'direct drive' TT
whose strobe (so he told me) worked from the same clock as the actual TT,
yet showed variations in TT speed. Now, ignoring the distinction between
phase and frequency lock that struck me as a weird idea because if the
clock ran fast or slow you'd never know from the strobe display as the TT
would simply 'track the strobe'. :-)

Of course, I'd have to actually do the mod before I could say with
absolute certainty that the variations were (almost) entirely due to the
mains alone.

IIRC There is a webpage that shows the recent variations in UK mains
frequency. It is regularly updated and provided by the people who operate
the grid IIRC. You could use that to see if what you get with your TT
follows what it shows. Alas, I can't recall the URL, so you'd need to
search for it, or have someone else post the address.

Slainte,

Jim

I have seen a site that provides a graph, but this one is quite nice
for an instantaneous reading.

http://www.dynamicdemand.co.uk/grid.htm#

d

Technics direct drive turntables
 

"MiNe 109" wrote in message
...
In article ,
"Iain Churches" wrote:

"MiNe 109" wrote in message
...

The labels also didn't like
independent pressing plant operators for a variety of reasons: dodgy
business practices ("breakage" quotas), etc.


I can't recall ever hearing the term "breakage quota" (ever tried to
break an LP ? :-) In the UK, "rejects" (usually due to misaligned
stampers) were at a low set percentage. Any press man worth his
salt could set the stamper with accuracy, and stopped the press at
regular intervals to check the geometry.

There was talk of independent factories "selling from the back door"
but this was quickly corrected by the insistance that "run ups" (that
should have been recycled) were pressed with blank white labels,
and by keeping tight control on the number of labels and sleeves
supplied to the plant.

In the UK, independent plants turned out a high
quality product.

The "breakage" was contractual! Artists were paid for 90% of units
pressed assuming 10% loss.

Ahaa! I see. It was the artist being penalised on sales, not
an independent plant charging the record company for breakage?
That's a litte suspect I would have thought, but if it was part of
the contract which the artist signed then there was nothing to
say afterwards.

The "assumed loss" figure is also very high, it seems to me, expecially
as it was common to punch out the label, shred rejects, and run-ups
and put them back into the vinyl hopper. A mis-aligned stamper was
not something one could charge the client for or make deduction.

Whether those "broken" lps went out the back
door benefitting the pressing plant or the front door benefitting the
record label I'm not sure.

Probably not unheard of:-)

Iain







Stephen

Technics direct drive turntables
 

"David Looser" wrote in message
...
"Iain Churches" wrote


I find it surprising that you should make such a sweeping statement
without
even knowing of the existence of Verdier, and without knowing that SME
make what are widely considered to be the finest turnable and pick up
arms in the world.

You must have missed the bit where I said I was familier with SME arms :-(


If you want to make a comparison, you simply pick those that
were considered the best at that time.The audition that I attended,
organised by the local section of the AES, picked Garrard 401,
EMT and a Telefunken 600, a Transcriptors.and couple of
others the names of which I no longer recall, plus an SME
and a Verdier. We had a panel of a dozen or so people.
Verdier was the tuntable of choice.

Was that "audition" conducted according to the requirementrs of a
listening test?, or did you all sit around listening together and in full
knowledge of what you were listening to? Because if the later the
"audition" has no value.

:-))


It was conducted at a broadcast facility. The panel participants
were all professionals and AES members

The turntables (which had been set up by broadcast
technical service) were in the control room, and the
listeners were in the studio area, with a drawn curtain
over the window between studio and control room.
There were nine turntables in all, so it was decided to
divide them into three groups of three, with the winner
of each group taking a place in the fourth session.

Levels were matched using the Decca test LP
ZAL 16234 -3F which I provided.

We were able to obtain three pressings of each piece of music
(classical, MOR, jazz) all with the same dash number.

None of us knew which TT we were listening to.
The control-room op switched sources

Would it not be more valuable to you to get up out
of that comfy armchair and do your own tests, and
reach your own conclusions?

What would my own tests prove?

You wouold at least have made an (albeit short)
acquaintance with some top of the range turntables,
and have something to to tell your children/grandchildren :-)

no more than your personal anecdotes do.

Perhaps you don't get invited to listening tests,
so given the medium in which we discuss here,
personal anecdotes are the best one can do.

I listen to vinyl so rarely that the relative merits of expensive TTs is
of little interest to me.

Yes. I understand that. It is the fact that people listen to
and enjoy music that is important, not the machine which
reproduces it.

Unlike Keith, apparently, (and in company with a very large proportion of
the population) I find vinyl irritating rather than "gripping" and only
use when there is no alternative.

Is the irritation due to the fact that your records are
in poor condition, and your TT not in good shape?.

I played two sides of Decca GOS 628-30
Bach: St John Passion. Choir of King's College
Cambridge/Lndon Philharmonia, late late last night on my
EMT 948 before turning in. It's a remarkable performance
I have played this boxed set many many times in the thirty
years I have owned it -Light surface here and there, but
no ticks, plops or scratches, and certainly none of the
"rifle shots" that Jim complains of.

It was indeed a pleasing experience.


I guess you don't watch British TV.

A busy schedule means that I don't have
the time to watch much TV at all. I try to
watch BBC World News and something
on the BBC HD channel as and when I can.

The Nordic satelite has 300 stations, some of them
from the UK.

There was a recent series called "Turn Back Time" in which the TV
production company took over some empty shops in the centre of Shepton
Mallet, set them up as shops from a particular era in the past and brought
in volunteer retailers to run them as shops of that era. The first era was
the 1870s, the last the 1970s (via Edwardian, 1930s, wartime and 1960s).

Yes I know of that series, - not the installment with the shops,
but modern familes going back to a 1950s home and lifestyle.
Most interesting.

In the 1970 era one shop was set up as a 1970s record shop and the
volunteer "owner" was required to sell recorded music 1970s style, ie on
vinyl. He didn't do well, the population of Shepton Mallet didn't make a
bee-line to his door demanding to buy LPs, quite the contrary. On the
other hand the woman who ran a 1970s style clothes shop did very well.

The number of turntables in Shepton Mallet can probably
be counted on the fingers of one hand. One needs customers
from a much greater catchment area. The wife of a colleague
of mine in the UK works as a volunteer in a charity shop.
They have boxes of vinyl, good bad and ugly, all at UKP1.
People, especially youngsters, come from miles around to
browse.

Did they have a 1970's style pub? 1950's would be better. A public
bar, a lounge bar and a snug. No TV or karaoke, but a billiard table,
a good dartboard, snacks on the counter, and in addition to best keg
bitter, also mild and brown ale not from bottles but on tap:-)

Regards
Iain

Technics direct drive turntables
 

"Iain Churches" wrote in message
...

"David Looser" wrote in message
...
"Iain Churches" wrote


Was that "audition" conducted according to the requirementrs of a
listening test?, or did you all sit around listening together and in full
knowledge of what you were listening to? Because if the later the
"audition" has no value.

:-))

It was conducted at a broadcast facility. The panel participants
were all professionals and AES members

I The turntables (which had been set up by broadcast
technical service) were in the control room, and the
listeners were in the studio area, with a drawn curtain
over the window between studio and control room.
There were nine turntables in all, so it was decided to
divide them into three groups of three, with the winner
of each group taking a place in the fourth session.

Levels were matched using the Decca test LP
ZAL 16234 -3F which I provided.

We were able to obtain three pressings of each piece of music
(classical, MOR, jazz) all with the same dash number.

None of us knew which TT we were listening to.
The control-room op switched sources

So you went some way towards making it a properly controlled test, but not
far enough. It seems that the panel knew that they were listening to
turntables and that everyone listened together, both very definite no-nos in
subjective testing. Was the order in which the turntables were heard varied
for each cycle? was the same turntable used twice as if it was a switch?
What were the voting arrangments? and how statistically significant were the
results?


You wouold at least have made an (albeit short)
acquaintance with some top of the range turntables,
and have something to to tell your children/grandchildren :-)

LOL! I've plenty of things to tell my children (and grandchildren if I ever
get any, my children don't seem in any hurry to provide them :-( ) far more
interesting than a nodding acquaintance with top of the range turntables.
Frankly my children couldn't care less about such things. As long as the
right sound comes out when they press the button that's all they care about
the technical aspects of sound eproduction.

no more than your personal anecdotes do.

Perhaps you don't get invited to listening tests,
so given the medium in which we discuss here,
personal anecdotes are the best one can do.

For 5 years my job consisted solely of providing technical support for
subjective tests. Granted these tests were for voice communications
equipment, not HiFi equipment, but the principles, particularly with regard
to eliminating bias, are exactly the same. Personal anecdotes are worth
precisely nothing.

I listen to vinyl so rarely that the relative merits of expensive TTs is
of little interest to me.

Yes. I understand that. It is the fact that people listen to
and enjoy music that is important, not the machine which
reproduces it.

So why are you spending so much time trying to persuade me of the merits of
overpriced turntables?

Unlike Keith, apparently, (and in company with a very large proportion of
the population) I find vinyl irritating rather than "gripping" and only
use when there is no alternative.

Is the irritation due to the fact that your records are
in poor condition, and your TT not in good shape?.

The irritation starts with the awkward size of the records and the short
playing time per side. It goes on with the careful handling needed to ensure
they don't get damaged, the need to check periodically for stylus wear etc.

Then there is the fact that even the most expensive and carefully set-up
turntable cannot totally eliminate the distortions inherent in the vinyl
medium. Distortions that a small, easily handled, CD does not have even when
played on a low-cost player.


I played two sides of Decca GOS 628-30
Bach: St John Passion. Choir of King's College
Cambridge/Lndon Philharmonia, late late last night on my
EMT 948 before turning in. It's a remarkable performance
I have played this boxed set many many times in the thirty
years I have owned it -Light surface here and there, but
no ticks, plops or scratches, and certainly none of the
"rifle shots" that Jim complains of.

*Any* LP will have "light surface" from beginning to end, and I don't think
I've ever met an LP that didn't have ticks at least even when brand new.

It was indeed a pleasing experience.

Fair enough. I can also enjoy listening to LPs that I've owned for years,
the pleasure I get from music outweighs the technical shortcomings of the
medium. I do, however, regard it as perverse that some people are still
recording LPs which others will buy at inflated prices when better
technologies have been around for over a quarter of a century.

David.

Technics direct drive turntables
 

In article , David Looser
wrote:
"Iain Churches" wrote in message
...


It was conducted at a broadcast facility. The panel participants
were all professionals and AES members

I The turntables (which had been set up by broadcast
technical service) were in the control room, and the listeners were in
the studio area, with a drawn curtain over the window between studio
and control room. There were nine turntables in all, so it was decided
to divide them into three groups of three, with the winner of each
group taking a place in the fourth session.

Levels were matched using the Decca test LP ZAL 16234 -3F which I
provided.

We were able to obtain three pressings of each piece of music
(classical, MOR, jazz) all with the same dash number.

None of us knew which TT we were listening to. The control-room op
switched sources

So you went some way towards making it a properly controlled test, but
not far enough. It seems that the panel knew that they were listening to
turntables and that everyone listened together, both very definite
no-nos in subjective testing. Was the order in which the turntables were
heard varied for each cycle? was the same turntable used twice as if it
was a switch? What were the voting arrangments? and how statistically
significant were the results?

Slightly different questions occur to me from reading the above.

How was it arranged to use the same cartridge and shift this from one 'TT'
to another? Or were ones assumed to be 'similar' used? Ditto for the arms.
Indeed, what cartridge and arms were used? I ask because my own experience
is that a change of cartridge etc (or a change of setup like tracking
geometry) makes a measurable difference. Hence the question is really, how
was it established that it was the "turntable" that made any detected
difference rather than something else.

How often was the test redone with the choice of individual LP swapped
around? Ditto for 'similiar' cartridges or arms.

Did the 'group' all sit and make their decisions together - or individually
with no chance to influence each other? If the test was as a group then
statistically there was essentially only 'one participant'. Not a group of
individual 'participants'.

Has this been published, or is there any other way for someone else to
examine the results and the methods?

The core problem is the common one for many 'audio tests'. How does anyone
establish that the 'reason(s)' put forward for what people perceived are
the genuine cause? i.e. How can anyone establish that the 'conclusion'
actually stands up?


I played two sides of Decca GOS 628-30 Bach: St John Passion. Choir of
King's College Cambridge/Lndon Philharmonia, late late last night on
my EMT 948 before turning in. It's a remarkable performance I have
played this boxed set many many times in the thirty years I have owned
it -Light surface here and there, but no ticks, plops or scratches,
and certainly none of the "rifle shots" that Jim complains of.

*Any* LP will have "light surface" from beginning to end, and I don't
think I've ever met an LP that didn't have ticks at least even when
brand new.

I have encountered some. Oddly enough, more often amongst the LPs that
companies sent to Armstrong that they knew we might use in Shows. :-) That
said, EMI generally still didn't seem to notice such matters.

The reality, though, was that for classical LPs I bought back in the 1970s
*most* had obvious manufacturing defects or faults like clicks. And as I've
pointed out in the past - there were also many articles and letters on the
topic from *retailers* as well as record listeners at the time. In some
cases giving detailed statistics.

Perhaps that has been one reason why I've tended to regard fussing about
choice of TT as being a 'displacement acitivity'. My experience is that
choice of cartridge and setup of that matters far more unless the TT really
is lousy. However I'd agree from my experience that clicks were less likely
to be audible with pop/rock material as the level of the music tended to be
high enough to mask them. Maybe they were called 'pop' music because of the
way the loudness concealed the 'pops'. ;-

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Technics direct drive turntables
 

"Iain Churches" wrote in message


I played two sides of Decca GOS 628-30
Bach: St John Passion. Choir of King's College
Cambridge/Lndon Philharmonia, late late last night on my
EMT 948 before turning in. It's a remarkable performance
I have played this boxed set many many times in the thirty
years I have owned it -Light surface here and there, but
no ticks, plops or scratches, and certainly none of the
"rifle shots" that Jim complains of.

Effective proof that Iain's ear's have subnormal HF response, and not by a
little.

I've never ever heard a LP that lacked audible surface noise unless
digitally processed. I've visited the homes of vinylphiles and heard their
hand-selected system, and I've auditioned some of the most highly regarded
high end audio shows in the world.

I am currently under the impression that some vinylphiles have the ability
to willfully enter a semi-conscious state where the usual audbile vinyl
grunge is not perceived by them.