ETA 7750 Vs. ETA 2892 with Chronograph module

[horol]

So I was recently looking at a Girard-Perregaux Square Cambered REF.
24990. I found out that the movement in there (gp 022C0) was actually
an ETA 2892 with a Chronograph module. It seems that the 2892 is a
great movement (from what I have seen), but why would Girard-perrgaux
decide to use that movement over a ETA 7750 or similar movement? What
are the advantages/disadvantages? Is one movement "better" then the
other? How exactly do modules attach to movements?

Thanks,
w0den

[Jack Denver]

Disadvantages - module sits on top of the base movement so pushers are not
in line with crown. Unless base movement is in very good condition, it will
not have the torque to drive the module, so the whole thing will need
service more often than usual. Modules are not considered watchmaker
serviceable and generally must be returned to manufacturer for exchange.
Overall thickness tends to be large. Calendar remains in the base movement
and has to be viewed thru a "tunnel" cut in the module.

Advantages - maker can continue to use and service their usual base
movement. Base movement may be of higher quality than 7750 which was
originally designed as low cost movement with plastic parts.

"horol" <w_o...@hotmail.com> wrote in message
news:1169665759.3...@l53g2000cwa.googlegroups.com...

[Revision]

A little info on Dubois-Depraz equipped 2892.

http://www.doxacms.com/movement.htm

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Posted via a free Usenet account from http://www.teranews.com

[Bruce Markowitz]

The biggest problem is that, depending on the design, the crown can dig into
your wrist, making the watch unwearable. This happened to me on an Omega
Speedy Pro reduced, had to return it.

"horol" <w_o...@hotmail.com> wrote in message
news:1169665759.3...@l53g2000cwa.googlegroups.com...

[Alan Dye]

I own an Omega Dynamic based on the 2892 with the Dubois Depraz
chronograph module and a few others with the 7750.

Both are fine movements, and will (with appropriate maintenance) last a
lifetime.

One bit of a draw back I've noticed about each one.

The 7750 has a rather heavy auto-winding rotor and with a flick of the
wrist you can get that thing really spinning which creates a noticeable
wobble of the watch on the wrist. It is subtle, but noticeable. Also,
there are plastic parts in the watch. I'm not particularly bothered by
this as the 7750 put chrono's in the sub $1000 price range and in order
to get in at that price point, some design choices had to be made to
keep price down and eliminate the column wheel. Plastic parts in
various cams are the result. Other than the mental aspect, you
shouldn't know or care about plastic parts as they remain functional.
(for that matter, Patek Phillipe is now putting silicon escapement
components in their watches...)

The 2892 w/DD module has a bit of what I could only describe as slop in
the drive train. When you are setting the watch, the movement hacks or
stops, you set the watch ahead 1 minute, wait until the time source
matches and then push in the crown. On most watches, the minute hand
starts moving right away, but with the DD, the watch goes about 45
seconds before the slop in the drive is taken up and the minute hand
starts moving. Since I'm a stickler for having the minute hand line up
with the markers when the second hand passes zero, I have to engage in a
bit of guessing in putting the minute hand ahead about 45 seconds so
that when the slop is taken up, the hand matches up on the seconds.

Both are fine however and should work well. If you want to consider a
higher end chronograph, maybe look at the Zenith El Primero or one of
the Omega watches with their 3313 movements.

Cheers,

Alan

[Richard Sexton]

In article <1169665759.3...@l53g2000cwa.googlegroups.com>,

I looked fairly seriously at a GP (4900, I think) once and
IF (and it might be a big if) I remember correcly, they
use an in house chrono module (if not it'll be the DD one).

Using a 2892 base caliber makes a lot of sense. They're not
expensive, quite accurate, a sturdy mechanical sign, anybody
can work on them and parts are available.

7750 is a built to cost movement and the would require too
much modification to bring it up to GPs statdards.

--
Need Mercedes parts? http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home pages: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net

[Richard Sexton]

In article <7PUth.37227$Gr2....@newssvr21.news.prodigy.net>,
Alan Dye <ala...@pacbell.net> wrote:

>horol wrote:
>The 7750 has a rather heavy auto-winding rotor and with a flick of the
>wrist you can get that thing really spinning which creates a noticeable
>wobble of the watch on the wrist. It is subtle, but noticeable. Also,
>there are plastic parts in the watch. I'm not particularly bothered by
>this as the 7750 put chrono's in the sub $1000 price range and in order
>to get in at that price point, some design choices had to be made to
>keep price down and eliminate the column wheel. Plastic parts in
>various cams are the result.

The LWC5100 has plastic parts too - and they're ok. But the plastic
parts in cal 7750 have been seen to warp.

[recommendation snipped]

Look at the GP Laureato with the in house chrono movement, too.

[Revision]

>
> I looked fairly seriously at a GP (4900, I think) once and
> IF (and it might be a big if) I remember correcly, they
> use an in house chrono module (if not it'll be the DD one).

I read somewhere that ETA has a 2894 that includes a chronometer
movement, and started thinking maybe that was in-house as well, but
really, if someone made a chrono module I think we would hear about it,
and that the GP and ETA modules are both Dubois-Depraz.

[Richard Sexton]

In article <45b997ad$0$24434$8826...@free.teranews.com>,

Revision <tsre...@nojunkr.net> wrote:
>>
>> I looked fairly seriously at a GP (4900, I think) once and
>> IF (and it might be a big if) I remember correcly, they
>> use an in house chrono module (if not it'll be the DD one).
>
>I read somewhere that ETA has a 2894 that includes a chronometer
>movement, and started thinking maybe that was in-house as well, but
>really, if someone made a chrono module I think we would hear about it,
>and that the GP and ETA modules are both Dubois-Depraz.

My undsetanding is they take the dd module apart, modify it
then put it back together. Similat to Omega's mopdificaitons
of chrono calibers. Ie a Lemania 1873 is one thing, Omega cal 861 is
more highly finished and adjusted to two positions (or something like
that)

[horol]

> Look at the GP Laureato with the in house chrono movement, too.

I really like the GP Laureato, but I had two problems with it:
1) out of my price range :(
2) I found the Chrono very hard to read. there are no markers for the
first 5 seconds, the minute hand sweeps, rather then jumps, so, since
there are no markers for the first 5 seconds, there are also no markers
for the first 5 minutes! It is somewhat difficult to even figure out
how many minutes have passed (with just a quick glance anyway).

Unfortunately I can't seem to find anyone who has the Square Cambered
in stock in NYC. A bunch of places are willing to order it if I put
down a deposit, but that is a lot of money to lay down to see a watch.
Oh well.

There are a couple of other watches I am looking at, one is the Omega
speedmaster day-date. How do you guys think it's quality compares to
that of the Square Cambered? It is a hell of a lot cheaper, and i like
the look a lot (even though it is totally different than that of the
square Cambered)?

Thanks for all your thoughts and help.