I was interested in how heavily modulated vinyl could be, so I popped
an old record (Long Hot Summer Night, Jimi Hendrix, Track Records
1968) under the microscope for a look. And what did I find? Two
adjacent grooves clearly broken into each other:

http://81.174.169.10/odds/grooves.jpg

Was this a really common back then, or is this kind of thing a rarity?

d

The worst I've encountered is the very audible signal from the adjacent turn
so to speak.
I wonder what your sample had been played on though.
Brian

--
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Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
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Don Pearce wrote in message news:4992beba.108434515@localhost...
I was interested in how heavily modulated vinyl could be, so I popped
an old record (Long Hot Summer Night, Jimi Hendrix, Track Records
1968) under the microscope for a look. And what did I find? Two
adjacent grooves clearly broken into each other:

http://81.174.169.10/odds/grooves.jpg

Was this a really common back then, or is this kind of thing a rarity?

d

On Wed, 04 Feb 2009 17:10:13 GMT, "Brian Gaff"
wrote:

The worst I've encountered is the very audible signal from the adjacent turn
so to speak.
I wonder what your sample had been played on though.
Brian

Just my own system and I have always been careful. I have a few vinyl
LPs that start loudly, and the opening chord is distinctly audible one
revolution before the actual start.

d

I often used to wonder about the out of phase effects on some records,
because in theory, these make the groove deeper and shallower, I'd imagine.
As for grooves actually intersecting, this would surely have shown up on the
master, I'd think. I had some issues in the 70s with that Pye plant pressing
records with bits of paper clearly poking out in some places. So much for
quality control of recycled Vinyl.
Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
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Don Pearce wrote in message news:4994cd6c.112197171@localhost...
On Wed, 04 Feb 2009 17:10:13 GMT, "Brian Gaff"
wrote:

The worst I've encountered is the very audible signal from the adjacent
turn
so to speak.
I wonder what your sample had been played on though.
Brian

Just my own system and I have always been careful. I have a few vinyl
LPs that start loudly, and the opening chord is distinctly audible one
revolution before the actual start.

d

"Brian Gaff" wrote in message
m...
I often used to wonder about the out of phase effects on some records,
because in theory, these make the groove deeper and shallower, I'd
imagine. As for grooves actually intersecting, this would surely have
shown up on the master, I'd think. I had some issues in the 70s with that
Pye plant pressing records with bits of paper clearly poking out in some
places. So much for quality control of recycled Vinyl.

Left and right channels out of phase will cause vertical groove modulation,
making the groove deeper and shallower. If you ever looked at stereo on an
oscilloscope in x-y mode, which pretty much displays the motion of the
stylus (if you're using a stylus ;-) you will see that the stylus moves in
all directions with normal stereo. The audio looks like a cotton ball on the
screen. In x-y mode, L=R (in phase) is normally a diagonal line going up to
the right; L=-R (out of phase) is normally a diagonal line going up to the
left.

Fortunately, long wavelengths and large excursions are mostly in the low
frequencies, which tend to have minimal out of phase characteristics (which
is why subwoofers are practical). But just in case, I do believe that record
cutters did blend left and right channels in the low frequencies, to reduce
the risk of the cutter leaving the surface entirely.

I have seen grooves intersect on records that I own, but the stylus rides a
long ways below the surface, so it is really only a problem if the *bottoms*
of the grooves overlap. Then the stylus would have a "choice" wouldn't it?
That would be bad...

"Karl Uppiano" wrote in message
...



Fortunately, long wavelengths and large excursions are mostly in the low
frequencies, which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).


More to the point as far as subwoofers are concerned, the ability of human
hearing to determine the direction of a sound source becomes less effective
as the wavelength lengthen, becoming pretty well non-existent at frequencies
of 50Hz and below. So not only does it not matter if these frequencies are
presented in mono, but it doesn't matter much where the subwoofer is in
relation to the subs either.

David.

On Feb 5, 11:23*pm, "Karl Uppiano" wrote:
Fortunately, long wavelengths and large excursions are
mostly in the low frequencies,

Uh, I would hope long wavelengths are mostly at low
frequencies. :-)

which tend to have minimal out of phase characteristics
(which is why subwoofers are practical).

I assume you mean "single" or "mono" subwoofers here.

I have seen grooves intersect on records that I own,
but the stylus rides a long ways below the surface,
so it is really only a problem if the *bottoms*
of the grooves overlap. Then the stylus would have
a "choice" wouldn't it?
That would be bad...

I have such a record in my collection. It's an old RCA
release of (I believe) Toscanini conducting Dukas'
Sorcerer's Apprentice. At the final orchestral crash
before the concluding section, on playing you hear
the final bars before that note leading up to it and
then, ... nothing but reverb tail. By adjusting the
anti-skating a little on the high side, it would play
just fine. I looked at it with a microscope once and,
indeed, there was a lot of confused grooves for about
2 revolutions.

On 2/4/2009 9:10 AM Brian Gaff spake thus:

The worst I've encountered is the very audible signal from the adjacent turn
so to speak.
I wonder what your sample had been played on though.

What you're describing has nothing to do with vinyl; you're talking
about "print-through", which is an artifact of the tape mastering
machine feeding the cutter, where you can hear signals from adjacent
lengths of tape.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair

David Nebenzahl wrote:
On 2/4/2009 9:10 AM Brian Gaff spake thus:

The worst I've encountered is the very audible signal from the
adjacent turn so to speak.
I wonder what your sample had been played on though.

What you're describing has nothing to do with vinyl; you're talking
about "print-through", which is an artifact of the tape mastering
machine feeding the cutter, where you can hear signals from adjacent
lengths of tape.

I've heard it a number of times over the years on first play of a vinyl
record, on both 33 and 45 rpm discs, and the pre-echo has always been
*exactly* one revolution ahead of the peak, both on the lead-in and
between tracks or in quiet passages. I'd put it down as an artifact of
either the material of the master deforming slightly while being cut, or
distortion of the plastic while the hot record was cooling after coming
out of the mould. Unless, of course, the feed reel on the tape deck
being used just happened to rotate at the same speed as the turntable.

--
Tciao for Now!

John.

On 2/4/2009 10:49 AM John Williamson spake thus:

David Nebenzahl wrote:

On 2/4/2009 9:10 AM Brian Gaff spake thus:

The worst I've encountered is the very audible signal from the
adjacent turn so to speak.
I wonder what your sample had been played on though.

What you're describing has nothing to do with vinyl; you're talking
about "print-through", which is an artifact of the tape mastering
machine feeding the cutter, where you can hear signals from adjacent
lengths of tape.

I've heard it a number of times over the years on first play of a vinyl
record, on both 33 and 45 rpm discs, and the pre-echo has always been
*exactly* one revolution ahead of the peak, both on the lead-in and
between tracks or in quiet passages. I'd put it down as an artifact of
either the material of the master deforming slightly while being cut, or
distortion of the plastic while the hot record was cooling after coming
out of the mould. Unless, of course, the feed reel on the tape deck
being used just happened to rotate at the same speed as the turntable.

The latter is much more likely. Can't see how the vinyl could deform
that much and still retain an accurate image from the mold.


--
Personally, I like Vista, but I probably won't use it. I like it
because it generates considerable business for me in consulting and
upgrades. As long as there is hardware and software out there that
doesn't work, I stay in business. Incidentally, my company motto is
"If this stuff worked, you wouldn't need me".

- lifted from sci.electronics.repair