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» 8mm Forum   » 8mm Forum   » GS1200 Capacitor - A winner !

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Author Topic: GS1200 Capacitor - A winner !
Lance Alspaugh
Expert Film Handler

Posts: 151
From: Los Angeles, Ca
Registered: Jun 2003


 - posted February 05, 2005 06:54 PM      Profile for Lance Alspaugh   Email Lance Alspaugh   Send New Private Message       Edit/Delete Post 
Fellow Collectors and S8 Buffs,

Mr. Elmo has supplied us with the ingredients for a 100 % improvement in magnetic sound recording quality on the GS 1200. The Capacitor works, works, works. For those of you who remix the audio on S8 prints, replacing the Capacitor that has been discussed here on the forum gives the sound quality a dramatic improvement on the Main and Balance track. Not a difficult change out and worth the time to do it. The capacitors are available in the United States from many electronic stores and online companies. Thanks Kevin for the research and information on making the hobby another cut above the norm.

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Paul Adsett
Film God

Posts: 4846
From: USA
Registered: Jun 2003


 - posted February 05, 2005 07:32 PM      Profile for Paul Adsett     Send New Private Message       Edit/Delete Post 
Kev,
Could you post a photo of where this capacitor is located in the GS1200, and also the specs for the replacement cap?

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

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Dimitrios Kremalis
Expert Film Handler

Posts: 129
From: Athens - Greece
Registered: Oct 2004


 - posted February 06, 2005 01:20 AM      Profile for Dimitrios Kremalis   Email Dimitrios Kremalis   Send New Private Message       Edit/Delete Post 
quote:
Kev,
Could you post a photo of where this capacitor is located in the GS1200, and also the specs for the replacement cap?

That would be indeed very interesting to see!

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Craig Hamilton
Jedi Master Film Handler

Posts: 501
From: Luton
Registered: Sep 2004


 - posted February 06, 2005 01:48 AM      Profile for Craig Hamilton   Email Craig Hamilton   Send New Private Message       Edit/Delete Post 
Kev, why not go one better and finish your website! Could prove very popular. [Wink]

Craig

--------------------
I dream of becoming a dealer!!!!!!
Is Perry's Movies for Sale.

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003


 - posted February 06, 2005 05:54 AM      Profile for Kevin Faulkner         Edit/Delete Post 
I will get a pic on here for you to see. Ummm! the web site!!! Time has been the problem where this is concerned. If there is anyone in the UK who is good at web site building then I could really do with some help! (Craig?)
This Cap change is looking like it needs to be done as a matter of course on these machines and I suspect that its because it sits above a large wattage resistor which runs hot when in the record mode. Heat does deteriorate capacitors. Naughty Elmo [Frown]
Glad it sorted your prob out Lance [Smile]

Kev. [Smile]

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GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003


 - posted February 06, 2005 07:23 AM      Profile for Ugo Grassi   Email Ugo Grassi   Send New Private Message       Edit/Delete Post 
These are "original Kevin Faulkner photos"
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The capacitor is behind the board (on the right)

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To arrive to the capacitor you have to disassemble the lid where the vu meters are.

[ February 06, 2005, 12:04 PM: Message edited by: Ugo Grassi ]

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Bye
Ugo

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003


 - posted February 06, 2005 08:33 AM      Profile for Kevin Faulkner         Edit/Delete Post 
Thanks, Ugo. Please note that the capacitor soldered in place on the board was there to test the theory out in the first place so should be ignored.
The capaictor must be 3300pf and rated at 600V DC. If a capacitor of lower voltage is used it will fail due to overheating. The cap has to put up with a very peaky wave form.
Its better if possible to use a 1 or 5% tolerance capacitor and it should be of the polystyrene (pref) or polyester type.
This is the board that lies behind the meters. There are 2 screws in the back of the machine which hold the cover in place and another along the front edge behind the drop down side cover which will also have to be removed.
The cap can be changed without the need for circuit board removal.

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Craig Hamilton
Jedi Master Film Handler

Posts: 501
From: Luton
Registered: Sep 2004


 - posted February 06, 2005 11:31 AM      Profile for Craig Hamilton   Email Craig Hamilton   Send New Private Message       Edit/Delete Post 
Kev, regarding your website, lets go for it. Geraldine would love a website for her business and we can both learn from our mistakes. I have a couple of programs capable of pulling this off so the HTML code should not be a problem along with the graphical layout. When it comes to Domain names, web hosting and all the other malarkey, then it’s down to you buddy. Great excuse to get together and run a few reels for inspiration and research. [Wink]

Craig

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I dream of becoming a dealer!!!!!!
Is Perry's Movies for Sale.

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Chris Quinn
Master Film Handler

Posts: 372
From: England, Bedfordshire.
Registered: Nov 2003


 - posted February 06, 2005 06:30 PM      Profile for Chris Quinn   Email Chris Quinn   Send New Private Message       Edit/Delete Post 
WARNING!!!
Changing this capacitor will change your life. You will want to re record everything you have. [Big Grin]
Chris.

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The other half thinks i'm up to something. Shes right of course.

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Ugo Grassi
Jedi Master Film Handler

Posts: 506
From: Avellino (Italy)
Registered: Dec 2003


 - posted February 06, 2005 06:49 PM      Profile for Ugo Grassi   Email Ugo Grassi   Send New Private Message       Edit/Delete Post 
quote:
Changing this capacitor will change your life. You will want to re record everything you have
ahahahaha [Big Grin] [Big Grin] [Big Grin] [Big Grin]
Right! the GS has a quality recording better than every other machine!

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Bye
Ugo

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Steve Klare
Film Guy

Posts: 6820
From: Long Island, NY, USA
Registered: Jun 2003


 - posted February 06, 2005 07:38 PM      Profile for Steve Klare   Email Steve Klare   Send New Private Message       Edit/Delete Post 
I have an ELMO ST-800 which is a pretty poor performer recording wise (massive fluctuations in recording level, with bursts of "too loud" mixed in with "not loud enough"). I am wondering if this capacitor is common to the ST-800's recording circuitry and if a swap out will help.

What is the sound improvement this change usually brings?

Also, what is the circuit function of this cap? (Coupling? Filtering?.....)

Thanks!

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All I ask is a wide screen and a projector to light her by...

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Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005


 - posted February 06, 2005 09:32 PM      Profile for Jan Bister   Email Jan Bister   Send New Private Message       Edit/Delete Post 
I was just going to ask the same thing! What, exactly, does this capacitor swap improve (and how much)?

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Call me Phoenix. *dusts off the ashes*

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003


 - posted February 07, 2005 04:43 AM      Profile for Kevin Faulkner         Edit/Delete Post 
This capacitor is the main cap which controls the frequency that the recording oscillator runs at. This is about 60Khz I think in the GS machines. As this drifts higher in value the frequency then drifts and will eventually go out of range to the point that the oscillator will stop running and you will no longer be able to record anything. Before it gets to this point you notice that the playback levels from your own recordings get lower and lower and a lack of Bass response is noticeable. Eventually you even start to get a sort of whistleing noise through the speakers when recording because the cicuits to filter the oscillator frequency out no longer do so because the frequency has driftef so much.
Hope that all makes sense. It certainly would if you put an oscilloscope on the heads and watched what was happening.
All the Elmo's use the same type of circuit for the record oscillator going right back to the early ST1200's so yes there could be problems with other machines such as the ST800.
I dont have a circuit diagram for that model so cant tell you what exactly the capacitor is etc.
It will be fairly similar though to the GS but really the problem with the GS is that Elmo have a high wattage resistor under the capacitor. This resistor get quite hot when in the record mode as it's there to lower the voltage to the red led that indicates you are recording on that track. This slowly cooks the capacitor with the result that it eventually gives up the ghost.
The problem you have with bad variable recordings could be down to head wear or maybe you have the ALC circuit switched in? I think the ST800 has that swichable?
The cap in question wouldnt give variable results but consistantley bad results.

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005


 - posted February 07, 2005 09:19 PM      Profile for Jan Bister   Email Jan Bister   Send New Private Message       Edit/Delete Post 
So in short, the capacitor swap restores the correct bias current that's mixed with the sound signal to be recorded before they're sent to the magnetic heads (all tape recorders use this principle, adding an extremely high-frequency current to the sound signal for proper EQ as well as recording of very low frequencies = bass). Am I right?

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Call me Phoenix. *dusts off the ashes*

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003


 - posted February 08, 2005 10:53 AM      Profile for Kevin Faulkner         Edit/Delete Post 
Jan, That sums it all up very well. Spot on. [Smile]

Kev [Smile]

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Jan Bister
Darth 8mm

Posts: 2629
From: Ohio, USA
Registered: Jan 2005


 - posted February 08, 2005 09:14 PM      Profile for Jan Bister   Email Jan Bister   Send New Private Message       Edit/Delete Post 
Thanks. Woohoo. [Big Grin]

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Call me Phoenix. *dusts off the ashes*

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Robert Aragon
Master Film Handler

Posts: 264
From: Carlsbad
Registered: Mar 2004


 - posted February 16, 2005 02:49 PM      Profile for Robert Aragon   Email Robert Aragon   Send New Private Message       Edit/Delete Post 
Would you believe I REPLACED the capcitor all by my lil' self! THANKS KEV!!!!!!!!
YEAH!!!!!!!

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Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003


 - posted February 16, 2005 05:05 PM      Profile for Kevin Faulkner         Edit/Delete Post 
Good Rob, I'm glad it worked out OK. See I told you it wasnt too difficult to do.
In every case so far this cap change has worked and cured many recording problems. [Smile]

Kev.

--------------------
GS1200 Xenon with Elmo 1.0...great combo along with a 16-CL Xenon for that super bright white light.

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Tony Milman
Phenomenal Film Handler

Posts: 1326
From: United Kingdom
Registered: Jun 2003


 - posted February 16, 2005 05:29 PM      Profile for Tony Milman   Author's Homepage   Email Tony Milman   Send New Private Message       Edit/Delete Post 
Now if only I thought of soldering it on the back of the board instead of taking the whole flippin thing apart [Eek!]

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Tony

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Dimitrios Kremalis
Expert Film Handler

Posts: 129
From: Athens - Greece
Registered: Oct 2004


 - posted February 17, 2005 05:47 AM      Profile for Dimitrios Kremalis   Email Dimitrios Kremalis   Send New Private Message       Edit/Delete Post 
Any link of a web shop in Europe offering these capacitors?
I asked Conrad, Germany's largest electro-provider and he didn't have it in his product list [Frown]

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Burton Sundquist
Master Film Handler

Posts: 270
From: Burnaby, B.C. Canada
Registered: Feb 2017


 - posted January 13, 2019 02:49 PM      Profile for Burton Sundquist   Email Burton Sundquist   Send New Private Message       Edit/Delete Post 
I have an issue Recording through Aux in on My GS-1200.
1. Spot rec switch on
2. Both left/right switches set to normal record
3. input levels both set so meters both peak at zero
4. both record switches depressed
5. forward switch activated.
Upon playback, left channel ( main stripe ) audio level quite low with volume set to halfway point and meter barely moving.
Right channel very good volume only at 1/3 point. It has better bass and treble too! meter moving to peak at zero.
I have tried on other test reels to eliminate stripe being the cause so it is a recording issue. My question is other that the recording capacitor, is there another component that may be the cause of the poor Recorded Audio on the main track? I would add that pre-recorded prints PLAY just fine on my unit.
Thanks in advance for any reply.

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