8mm Forum: Goko RM-8008, tune-up help needed

8mm Forum

my profile | my password | search | faq | register | forum home

next oldest topic

next newest topic

»	8mm Forum » 8mm Forum » Goko RM-8008, tune-up help needed

UBBFriend: Email this page to someone!

Author

Topic: Goko RM-8008, tune-up help needed

Jan Bister
Darth 8mm

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

posted July 01, 2006 10:35 AM

Email Jan Bister

Send New Private Message

Edit/Delete Post

I've only mentioned this in passing recently... but I'm the proud owner of a Goko RM-8008 stereo recording editor these days. It works very well - have cleaned the entire film path, demagnetized the soundheads, and done some test viewings w/ sound playback followed by actual recording tests. (Hooray for pre-striped Kodak home movies!)
The sound quality upon playback is absolutely fantastic. [Smile]

[Smile]

The problem is there is extreme flutter in the sound... no wow, just flutter. Can't quite figure this out as everything is clean, speed settings are correct (I've also turned all the dials all the way up and down several times for self-cleaning, including the pitch control). When I played back a Roger Rabbit cartoon (stereo Derann print) sound was rock-steady, but my own recordings suffer from flutter. Could this have to do with the different film stock I used for recording? The stripe itself? Or do I need to replace the belts inside the machine (I did notice the motor drives the flywheel directly via a belt - it seems to look OK but ya never know - also the belt from the motor to the take-up pulley does have a slight kink in it)...

Jean-Marc, I need you. [Smile]

[Smile]

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted July 01, 2006 11:05 AM

Edit/Delete Post

Jan, I too have one of these units but I must confess that I have not done any recording on it.

Is the flutter on both tracks or is it on the balance stripe only. The reason i ask is that I get flutter on the GS with Ceratin Derann striped film. Its because the stripe is a little wider than it should be and is interupted slightly by each sprocket hole resulting in a level drop at each sprocket hole. This of coures gives rise to a flutter sound.

On the goko like most editors there is no intermitant movement to the film so you should never get flutter....wow yes but not flutter.

My Goko does a reasonable job or playing back sound but the balance track is much lower level than the main stripe. I think the heads on mine need replacing. I have 2 sets of GS heads and I was going to try a set in this unit but not got round to it. The goko mainly gets used for film cleaning etc these days.

Kev.

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

| IP: Logged

Jan Bister
Darth 8mm

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

posted July 01, 2006 11:24 AM

Email Jan Bister

Send New Private Message

Edit/Delete Post

Well... I recorded on pre-striped Kodachrome 40 film (someone else's home movies I ended up with)... Should probably test whether the flutter was recorded or only occurred during playback. Good point about the balance stripe, I'll give it a listen again on the main stripe only and see if it's OK. The Roger Rabbit cartoon played back perfectly... will have to tinker with it again I guess. (For now I'm back to the two Sankyos, though... sometimes I go through several patients a day on my lab examination table.) [Big Grin]

[Big Grin]

BTW - using an RM-8008 for playback/cleaning only? What else do you do, drive a Ferrari on Sundays in a 30km/h zone? [Big Grin]

[Big Grin]

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted July 01, 2006 06:40 PM

Edit/Delete Post

No. I do that with the Ninja! Oh such great fun!

Kev

[Smile]

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

| IP: Logged

Jan Bister
Darth 8mm

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

posted July 02, 2006 12:01 AM

Email Jan Bister

Send New Private Message

Edit/Delete Post

WOW!

[Eek!]

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

Jean-Marc Toussaint
Film God

Posts: 2392
From: France
Registered: Oct 2004

posted July 02, 2006 03:30 AM

Author's Homepage

Email Jean-Marc Toussaint

Send New Private Message

Edit/Delete Post

OMG! The spools are upside down!!!! [Wink]

[Wink]

Cool ride, Kev.

--------------------
The Grindcave Cinema Website

| IP: Logged

Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted July 02, 2006 05:22 AM

Edit/Delete Post

Thanks Guy's. [Smile]

[Smile]

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

| IP: Logged

Jean-Marc Toussaint
Film God

Posts: 2392
From: France
Registered: Oct 2004

posted July 02, 2006 05:52 AM

Author's Homepage

Email Jean-Marc Toussaint

Send New Private Message

Edit/Delete Post

We've got quite OT. Sorry, Jan.
I have noticed the same thing regarding the 8008 balance track (it's much weaker than the main one). But then again, the sound head might be at fault. Genrally speaking, playback is very powerful. I haven't tried recording yet (I have a Grassi Special 1200 for that purpose).
That flutter issue... Could that be associated with the fact that the film and the stripe aren't pressed properly against the head? I had a very similar problem with a GS - only detectable when recording, never in PB prerecorded prints - which was solved by adjusting the whole pinch assay and changing that "pinned black cube" that's pressing the stripes onto the sound heads.

--------------------
The Grindcave Cinema Website

| IP: Logged

Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted July 02, 2006 06:34 AM

Edit/Delete Post

I think agree with you Jean marc. Because the film drives straight through on the editor, unlike a projector with its stop and start movement, you shouldnt get flutter. Its either something like bad stripe or it could be the little head pressers are worn allowing some form of vibration as the film passes through the sound block.

Kev.

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

| IP: Logged

Jan Bister
Darth 8mm

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

posted July 02, 2006 06:56 AM

Email Jan Bister

Send New Private Message

Edit/Delete Post

All good points, just one problem... how could it be a mechanical issue when playing back pre-recorded sound film results in NO flutter whatsoever whereas the Goko's own recordings do? Doesn't make sense to me. Also I can't say I'm having any issues with the balance track being softer than the main track, they both come through equally loud (and record the same way), both sound great and neither exhibit any dropouts. It's just the flutter that's the problem (more like a really fast wow, but without any discernible rhythm to it).

Does either of you know how to properly disassemble the front of the editor? i.e. get beneath all the controls and down where the motor gears and belts are? They're unreachable from behind...

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

Alan Rik
Film God

Posts: 2211
From: New York City, NY, USA
Registered: Jun 2003

posted July 02, 2006 08:30 AM

Email Alan Rik

Send New Private Message

Edit/Delete Post

I had a Goko for a little bit and the re-recorded sound was perfect. No wobbly bits at all. The first was prestriped K40 from the 80's and the other was a commercial film. The Snowman I think I tried. Sound was perfect with very smooth highs. If I could of got that to synch up it would have been as good if not better than the GS recordings.

| IP: Logged

Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted July 02, 2006 05:42 PM

Edit/Delete Post

Well I think I have to say Jan, that I'm at loss on this one. I cant think of any reason why your own recordings would exhibit this effect but no sign of it at all on playback of comercial stuff.

Wrotg remembering though that any slight problem will be magnified 2 fold when recording and playing back.

To strip the unit down you must remove the front plate by undoing the 2 tiny screws and then removing all the knobs etc. You can also remove the back by undoing 6 screws, one on each side, 2 on the bottom, and 2 at the rear near the mains connector etc.

Hope that helps, Kev.

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

| IP: Logged

Jean-Marc Toussaint
Film God

Posts: 2392
From: France
Registered: Oct 2004

posted July 04, 2006 12:19 PM

Author's Homepage

Email Jean-Marc Toussaint

Send New Private Message

Edit/Delete Post

Jan, as said in my previous post, there's a slight chance that this incident can't be detected with prerecorded sound film. The exact same thing happened on my GS.

If you look at the Goko, remove the plastic part that covers the whole sound head assay, just pull on the command knob and pull on the cover.

Put the knob back and switch it to the "play" position. You will see a plastic white cube with 4 pins lowering itself on top of the sound heads. The pins covering the recording heads might be worn out and they are much less tolerant than the one covering the playback heads.

Then, it's a matter of recutting the pins with an Xacto knife, in order to make them sharper and find a way to make the cube go like a fraction of a millimeter lower. This might solve your issue.

--------------------
The Grindcave Cinema Website

| IP: Logged

Jan Bister
Darth 8mm

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

posted July 04, 2006 12:46 PM

Email Jan Bister

Send New Private Message

Edit/Delete Post

Good idea, thanks. [Smile]

[Smile]

I'll give this a shot. BTW, there is only one soundhead for both playback AND recording (not counting the erase head of course), but you (& Kevin) would be right in that it could be a problem not noticeable during playback of pre-recorded sound.
I'm also a bit concerned about the supply reel friction (which gently brakes the reel) as it seems a little bit too high. But of course I'm not going to mess with that until I try the most obvious things first.
As always, more to come...

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

Jan Bister
Darth 8mm

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

posted July 08, 2006 10:34 AM

Email Jan Bister

Send New Private Message

Edit/Delete Post

Have successfully removed the front of the unit... and it's got to be the belts. They don't really run true, seems they went out of shape from the machine sitting unused for so long. I can see a "hiccup" everytime the belt runs once around the pulleys. And gently lifting the pressure pins off the soundhead does nothing, either (other than muffling the sound). [Roll Eyes]

[Roll Eyes]

I heard somewhere that belts can be put in hot water for a while to make them go back to their circular shape and restore elasticity. Is this true? How hot should the water be, and how long to soak the belt?

EDIT: Nevermind, the belt just BROKE while I was making another recording [Frown]

[Frown]

[ July 08, 2006, 12:01 PM: Message edited by: Jan Bister ]

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

Kevin Faulkner
Film God

Posts: 4071
From: Essex UK
Registered: Jun 2003

posted July 08, 2006 03:48 PM

Edit/Delete Post

That was a little unfortunate. Dont know where you get the belts from for these. Maybe you might need to ney some of that belting material where you melt the ends together one cutting to the correct length.

Lets hope that sorts the problem.

Kev.

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

| IP: Logged

Jan Bister
Darth 8mm

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

posted July 08, 2006 06:02 PM

Email Jan Bister

Send New Private Message

Edit/Delete Post

Just my luck, huh? And to think I just ordered a bunch of cans from Larry Urbanski - if I'd known I was going to need belt material too, I could've saved me the shipping for a separate order. Sigh [Frown]

[Frown]

But in any case, I pretty much found the cause of the whole fluttering problem...

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

Jan Bister
Darth 8mm

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

posted August 13, 2006 05:18 PM

Email Jan Bister

Send New Private Message

Edit/Delete Post

Have I ever mentioned that I'm hearing-disabled?

Well, I don't usually wear my hearing-aid at home when tinkering with stuff, and I learned yesterday that was a mistake! When I did have it on and was working on the Goko editor again, I heard a fast rhythmic click-click-click-click-click whenever the motor was running. I'd never heard it before and was going crazy not being able to figure out what was causing the sound flutter! DOH!!!

Just a strange story I thought I should share with everyone... Remember, when you tinker with gear, listen to it. [Roll Eyes]

[Roll Eyes]

[Razz]

[Big Grin]

--------------------
Call me Phoenix. *dusts off the ashes*

| IP: Logged

All times are Central

Move Topic

Delete Topic

next oldest topic

next newest topic

Printer-friendly view of this topic

Visit www.film-tech.com for free equipment manual downloads. Copyright 2003-2019 Film-Tech Cinema Systems LLC

UBB.classic^TM 6.3.1.2