MONO GROOVE CHARACTERISTICS

[dondaben]

Lately I've been fascinated by the sonics of the GE VR II mono
cartridge. I am rediscovering lost dimensions hidden in old 50's era
LPs. But I have also been concerned about playing mono albums pressed
after the late 60's. My question is: did the monophonic groove change
around the time that stereo records became the industry standard? Were
the pressings of the past 40 years cut with a stereo groove yet had a
mono output? I don't want to damage my newer records by playing them
with an incompatible pick-up. Any help would be appreciated.

[Olafur Gunnlaugsson]

Þann 05/01/2010 23:06, dondaben skrifaði:
> Lately I've been fascinated by the sonics of the GE VR II mono
> cartridge. I am rediscovering lost dimensions hidden in old 50's era
> LPs. But I have also been concerned about playing mono albums pressed
> after the late 60's. My question is: did the monophonic groove change
> around the time that stereo records became the industry standard? Were
> the pressings of the past 40 years cut with a stereo groove yet had a
> mono output? I don't want to damage my newer records by playing them
> with an incompatible pick-up. Any help would be appreciated.

Yes and no, stereo groves are thinner, not a huge notable difference
with a good line contact stylus, but very noticeable with a conical one.

Mono standard grooves are 25um, stereo are 18, but in the 50s LPs were
often cut wider, up to 28um, later even in some third world countries,
this is not a problem in this instance really since a mono stylus should
be cut for 25, can be a minor problem if you are using a stereo stylus.
I have not heard of thinner mono grooves, but that is a possibility but
not a concern, the smaller grooves of even the 18um stereo records can
be played by a wider stylus without any harm, it simply sticks out of
the groove a bit and surface contact is ever so slightly less than optimal.

Mono cartridges do sound a lot better for playing mono material, lots of
small reasons for this that make up a noticeable difference, but I would
try something more modern than the GE, and I would check and double
check the stylus under a microscope before using it.

[Bob Eld]

"Olafur Gunnlaugsson" > wrote in message
...
> Þann 05/01/2010 23:06, dondaben skrifaði:
> > Lately I've been fascinated by the sonics of the GE VR II mono
> > cartridge. I am rediscovering lost dimensions hidden in old 50's era
> > LPs. But I have also been concerned about playing mono albums pressed
> > after the late 60's. My question is: did the monophonic groove change
> > around the time that stereo records became the industry standard? Were
> > the pressings of the past 40 years cut with a stereo groove yet had a
> > mono output? I don't want to damage my newer records by playing them
> > with an incompatible pick-up. Any help would be appreciated.
>
> Yes and no, stereo groves are thinner, not a huge notable difference
> with a good line contact stylus, but very noticeable with a conical one.
>
> Mono standard grooves are 25um, stereo are 18, but in the 50s LPs were
> often cut wider, up to 28um, later even in some third world countries,
> this is not a problem in this instance really since a mono stylus should
> be cut for 25, can be a minor problem if you are using a stereo stylus.
> I have not heard of thinner mono grooves, but that is a possibility but
> not a concern, the smaller grooves of even the 18um stereo records can
> be played by a wider stylus without any harm, it simply sticks out of
> the groove a bit and surface contact is ever so slightly less than
optimal.
>
> Mono cartridges do sound a lot better for playing mono material, lots of
> small reasons for this that make up a noticeable difference, but I would
> try something more modern than the GE, and I would check and double
> check the stylus under a microscope before using it.

I think the OP's question is more one of vertical compliance than groove
dimension. The GE cartridges were very poor in vertical compliance and could
allegedly damage stereo recordings because the stylus does not move well in
the vertical direction. The question is: are later mono records cut on
stereo equipment and therefore do they have a vertical component to their
grooves? Or, are they truly lateral recordings with only horizontal motion?
If so, the GE cartridge should not damage them. But, if there is a vertical
component, they could be damaged by a mono cartridge.

I don't have the answer, but I would guess that at least some modern mono
recordings were cut on stereo equipment and may have a vertical component to
their grooves. In other words, one should use a cartridge with vertical
compliance to play all modern recordings just to be safe.

[Olafur Gunnlaugsson]

Þann 10/01/2010 16:20, Bob Eld skrifaði:
> "Olafur > wrote in message
> ...
>> Þann 05/01/2010 23:06, dondaben skrifaði:
>>> Lately I've been fascinated by the sonics of the GE VR II mono
>>> cartridge. I am rediscovering lost dimensions hidden in old 50's era
>>> LPs. But I have also been concerned about playing mono albums pressed
>>> after the late 60's. My question is: did the monophonic groove change
>>> around the time that stereo records became the industry standard? Were
>>> the pressings of the past 40 years cut with a stereo groove yet had a
>>> mono output? I don't want to damage my newer records by playing them
>>> with an incompatible pick-up. Any help would be appreciated.
>>
>> Yes and no, stereo groves are thinner, not a huge notable difference
>> with a good line contact stylus, but very noticeable with a conical one.
>>
>> Mono standard grooves are 25um, stereo are 18, but in the 50s LPs were
>> often cut wider, up to 28um, later even in some third world countries,
>> this is not a problem in this instance really since a mono stylus should
>> be cut for 25, can be a minor problem if you are using a stereo stylus.
>> I have not heard of thinner mono grooves, but that is a possibility but
>> not a concern, the smaller grooves of even the 18um stereo records can
>> be played by a wider stylus without any harm, it simply sticks out of
>> the groove a bit and surface contact is ever so slightly less than
> optimal.
>>
>> Mono cartridges do sound a lot better for playing mono material, lots of
>> small reasons for this that make up a noticeable difference, but I would
>> try something more modern than the GE, and I would check and double
>> check the stylus under a microscope before using it.
>
> I think the OP's question is more one of vertical compliance than groove
> dimension. The GE cartridges were very poor in vertical compliance and could
> allegedly damage stereo recordings because the stylus does not move well in
> the vertical direction. The question is: are later mono records cut on
> stereo equipment and therefore do they have a vertical component to their
> grooves? Or, are they truly lateral recordings with only horizontal motion?
> If so, the GE cartridge should not damage them. But, if there is a vertical
> component, they could be damaged by a mono cartridge.
>
> I don't have the answer, but I would guess that at least some modern mono
> recordings were cut on stereo equipment and may have a vertical component to
> their grooves. In other words, one should use a cartridge with vertical
> compliance to play all modern recordings just to be safe.
>
>

compliance is not a problem, in this instance