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david correia david correia is offline
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Default Dual 621 turntable fix

I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com
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Fred[_13_] Fred[_13_] is offline
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Default Dual 621 turntable fix


"david correia" wrote in message ...
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com


If it's like most other Duals, there's a pin coming down from the tone arm that
moves the arm when a platform comes up underneath it and moves sideways,
moving the pin and therefore the arm. There is a little rubber cup on the bottom
of that pin that wears out, and then the platform doesn't put enough pressure on
the pin to make it move with the platform. You'll have to find or make some kind
of a substitute for that cup as Dual is gone and replacements are unobtanium.
Playing with different lubricants and amounts of lube for the upper side of the
platform can also yield results. There needs to be some lube or the rubber cup
will wear out in short order, but if it's too slippery the arm won't move. There
may also be a way to adjust the height of the platform when in the up position -
too low and the arm won't move for lack of pressure on the pin; too high and it
jams the pin and the arm won't move. Duals are finicky. Very finicky.

HTH,

Fred


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Reinhard Zwirner[_2_] Reinhard Zwirner[_2_] is offline
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Default Dual 621 turntable fix

david correia schrieb:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??


Maybe you can find something helpful he

http://wegavision.pytalhost.com/dual.html

("Anleitung" = user manual, "Service" = service manual)

Unfortunately, the service manual for just the 621 isn't provided, but I
think it's highly propable to find the manual for a comparable type.

HTH

Reinhard
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Scott Dorsey Scott Dorsey is offline
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Default Dual 621 turntable fix

david correia wrote:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??


It's probably not anywhere near as bad as the older idler-drive duals where
everything was mechanical. They were just a horrible nightmare. The direct
drive ones aren't so bad; I would first check the contacts and make sure the
control board knows where the arm is. Get the service manual, they are out
there!

Note that these do have audible cogging and some arm issues; Paul Stamler's
putty trick might help.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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PStamler PStamler is offline
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Default Dual 621 turntable fix

On Jan 18, 1:43*pm, (Scott Dorsey) wrote:

Note that these do have audible cogging and some arm issues; Paul Stamler's
putty trick might help.


With the arm, not the cogging!

For those who haven't encountered it, the putty trick is to wrap a
thin donut of Mortite, 3M Strip-Calk, or plumber's stainless putty
around the tonearm's shaft. If you do one halfway down the shaft and
another 1/3 of the way from the headshell to the pivot, it helps damp
down nasty resonances. You don't need much putty; if you make the
donut from a piece of unstretched Mortite (about 4mm in diameter)
then, once it's on the arm, flatten it out, you'll be fine. Of course,
the added weight will mean you need to reset the tracking force.

This won't be necessary on a really good tonearm, but on a less
stellar one it can help a lot with damping nasty resonances.

Peace,
Paul


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William Sommerwerck William Sommerwerck is offline
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Default Dual 621 turntable fix

...the putty trick is to wrap a thin donut of Mortite, 3M
Strip-Calk, or plumber's stainless putty around the
tonearm's shaft.


Better make sure it can't fall off while the record's playing...


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Harry Lavo Harry Lavo is offline
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Default Dual 621 turntable fix


"Scott Dorsey" wrote in message
...
david correia wrote:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??


It's probably not anywhere near as bad as the older idler-drive duals
where
everything was mechanical. They were just a horrible nightmare. The
direct
drive ones aren't so bad; I would first check the contacts and make sure
the
control board knows where the arm is. Get the service manual, they are out
there!

Note that these do have audible cogging and some arm issues; Paul
Stamler's
putty trick might help.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."


Actually, if you like the TT but don't want to bother with the fix, look for
a 701 or a 601. The 701, Dual's first and flagship Direct Drive, had a
massive platter that overcame cogging, and a better, extra-long tonearm.
The 601 featured moderately-heavy platter and a belt drive, and if
well-mainained is an excellent turntable. Both are semi-automatic
turntables and therefore are simpler than automatic Duals. However, be
forewarned that almost all Duals will need some attention to their
auto-mechanisms sometimes during their lifetime.


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Default Dual 621 turntable fix

Harry Lavo wrote:
Actually, if you like the TT but don't want to bother with the fix, look for
a 701 or a 601. The 701, Dual's first and flagship Direct Drive, had a
massive platter that overcame cogging, and a better, extra-long tonearm.
The 601 featured moderately-heavy platter and a belt drive, and if
well-mainained is an excellent turntable. Both are semi-automatic
turntables and therefore are simpler than automatic Duals. However, be
forewarned that almost all Duals will need some attention to their
auto-mechanisms sometimes during their lifetime.


Attention that will probably involve an incinerator or trash compactor....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Default Dual 621 turntable fix

On Jan 18, 3:36*pm, "William Sommerwerck"
wrote:
...the putty trick is to wrap a thin donut of Mortite, 3M
Strip-Calk, or plumber's stainless putty around the
tonearm's shaft.


Better make sure it can't fall off while the record's playing...


As long as it's a closed ring with the ends firmly joined together,
and the ring is pressed firmly against the shaft and flattened out, it
won't fall off. At least, the ones I've put on never have, and one of
them's been in place for 15 years.

If you're really paranoid put the gap at the bottom of the ring; then
you'll have some help from gravity. But you won't need it.

Peace,
Paul
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Default Dual 621 turntable fix

Dana subota, 15. siječnja 2011. u 00:12:52 UTC+1, korisnik david correia napisao je:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com


Hi David, did you have any luck in fixing this... coz I have a same problem.
Unfortunately the Service Manual that I found on the net is in German.

Kres


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Default Dual 621 turntable fix

Dana subota, 15. siječnja 2011. u 00:12:52 UTC+1, korisnik david correia napisao je:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com


LOL, no! It's just my broken English

Kres
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Chuck[_11_] Chuck[_11_] is offline
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Default Dual 621 turntable fix

On Thu, 7 Feb 2019 13:51:09 -0800 (PST), wrote:

Dana subota, 15. sije?nja 2011. u 00:12:52 UTC+1, korisnik david correia napisao je:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com

Hi David, did you have any luck in fixing this... coz I have a same problem.
Unfortunately the Service Manual that I found on the net is in German.

Kres

There is a plate that moves back and forth under the arm assembly. A
pin with a rubber boot presses against the plate. That boot can wear
out. Back in the day, I repaired thousands of Duals but I have no idea
where you could obtain the boot today. If the boot is still there you
could try cleaning the bottom of it and the top of the sliding plate.
Put a thin layer of GC Phonolube on the plate and let it cycle for
awhile. If you are lucky, it will begin working again.
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Default Dual 621 turntable fix

Dana subota, 15. siječnja 2011. u 00:12:52 UTC+1, korisnik david correia napisao je:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com


Chuck,
I posted one picture on my facebook page (coz I didnt find way to post it directly here), here is the link...
https://www.facebook.com/photo.php?f...type=3&theater
Can you tell me is this pin marked with number 206 pin you are talking about?
Maybe there is a way to make such a rubber cap, or something else that would work as well.
Anyhow thank you for your answer.
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Default Dual 621 turntable fix

Dana subota, 15. siječnja 2011. u 00:12:52 UTC+1, korisnik david correia napisao je:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com


Or maybe after 40 years is time for the new turntable


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Scott Dorsey Scott Dorsey is offline
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Default Dual 621 turntable fix

wrote:

Hi David, did you have any luck in fixing this... coz I have a same proble=
m.=20
Unfortunately the Service Manual that I found on the net is in German.


These things are horrible abominations that need to die, but they are really
not difficult to work on if you think about the mechanics. Everything is
controlled by the big yellow brain cam and if something is moving or not moving
it is likely because whatever the brain cam is supposed to be shifting is not
moving.

What is useful about the service manual are the tear-down diagrams, the text
is really not useful anyway. Turn the thing on the side and watch what
happens as you set the lever into play... see how the brain cam turns and
what it's moving. It may not be in the right position or one of the gadgets
that follows it may be cracked or broken.

But really, the whole idea of stacking records and autochanging is a bad
one if you care about your records.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Chuck[_11_] Chuck[_11_] is offline
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Default Dual 621 turntable fix

On Fri, 8 Feb 2019 11:57:26 -0800 (PST), wrote:

Dana subota, 15. sije?nja 2011. u 00:12:52 UTC+1, korisnik david correia napisao je:
I got a mint Dual 621 turntable with a Grado cartridge that sounds fine.
The tone arm is supposed to be fully automatic. But it no longer moves
over to the beginning of the record when starting it, nor does it move
back to the right when it lifts at the end of a record. It will just go
up and down. It plays as a manual TT, but I want it fully automatic
again.

How much of a pita is this to fix??




David Correia
www.Celebrationsound.com

Chuck,
I posted one picture on my facebook page (coz I didnt find way to post it directly here), here is the link...
https://www.facebook.com/photo.php?f...type=3&theater
Can you tell me is this pin marked with number 206 pin you are talking about?
Maybe there is a way to make such a rubber cap, or something else that would work as well.
Anyhow thank you for your answer.

Yes, It is the cap on 206 and one cleans and lubes the top of the
right end of 183. If the cap is missing, something else might work. I
worked for one of the largest U.S. Dual dealers so I had a ready
source of parts so I never had to experiment. Good luck.
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Edi Zubovic Edi Zubovic is offline
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Default Dual 621 turntable fix

On Fri, 08 Feb 2019 11:05:34 -0600, Chuck wrote:

Hi David, did you have any luck in fixing this... coz I have a same problem.
Unfortunately the Service Manual that I found on the net is in German.

Kres

There is a plate that moves back and forth under the arm assembly. A
pin with a rubber boot presses against the plate. That boot can wear
out. Back in the day, I repaired thousands of Duals but I have no idea
where you could obtain the boot today. If the boot is still there you
could try cleaning the bottom of it and the top of the sliding plate.
Put a thin layer of GC Phonolube on the plate and let it cycle for
awhile. If you are lucky, it will begin working again.



Hello R.A.P. after a long long time, Hello Scott and other members.

-- Yes this is a known problem with Dual changers, go to German Ebay
and search for "Dual Steuerpimpel".

Best,

Edi Zubovic, Crikvenica, Croatia
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[email protected] kbosnar18@gmail.com is offline
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Default Dual 621 turntable fix

Thx Edi
There tones of it, all kind... for every Dual model.
Tell me Edi do you have maybe repair shop?
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On Sun, 10 Feb 2019 08:06:42 -0800 (PST), wrote:

Thx Edi
There tones of it, all kind... for every Dual model.
Tell me Edi do you have maybe repair shop?



--Well not an "official" one, but I do have a well equipped shop.

Best, Edi Zubovic, Crikvenica, Croatia


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Edi,
da li bi se Vi privatili servisiranja mog gramofona, uz naravno neku razumnu nadoknadu.
Vidim da ste stručnjak a ja sam po tom pitanju totalni diletant.
Gramofon je kod mene već skoro 40 godina i nikad nije bio otvaran do prije neki dan. Trebalo bi ga generalno podmazat i sredit to automatsko startanje i gašenje.
Jedino što je novo na njemu je igla. Zvučnica isto nije nikada dirana al mi se čini da je ok.
Ako ste zainteresirani slobodno me nazovite na
091 940 8975.
Živim u Gorskom kotaru a radim na Urinju u rafineriji tako da mi nije problem doći do Crikvenice.
Pozdrav
Krešimir Bosnar.
P.S.
Ta plastična kapica se raspala
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On Sun, 10 Feb 2019 15:25:48 +0100, Edi Zubovic edi.zubovic[rem
1 wrote:

Dual Steuerpimpel


Thanks for this information. If I can find a source for the idlers, I
might start repairing these again.
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On Sun, 10 Feb 2019 11:15:12 -0600, Chuck wrote:

On Sun, 10 Feb 2019 15:25:48 +0100, Edi Zubovic edi.zubovic[rem
1 wrote:

Dual Steuerpimpel


Thanks for this information. If I can find a source for the idlers, I
might start repairing these again.



--You're wellcome. Idler wheels are scarce. I don't know who makes the
new ones or refurbishes their old rubber. Here or there they appear
either as used or (rarely) NOS at Ebay. Try Dual Treibrad at German
Ebay. Usually they aren't so problematic unless they are very worn
out or they somehow remained pressed against drive shaft.

Oh yes! Antiskating wheels can be easily found as well. These can be
often found cracked.


Best, Edi Zubovic, Crikvenica, Croatia


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Edi Zubovic edi.zubovic[rem wrote:

--Now I've been thinking about this a bit, if the turtable was mint
there shouldn't be any problem with the "Steuerpimpel" unless it is
cracked due to hardened plastic over the time. I doubt that.

If I faintly remember, Dual changers may get out of synch after
transport.


They get out of synch ALL THE TIME. You don't need to transport them,
you can just flip the levers in the wrong directions while it's doing
something and get it out of synch.

This is why I say... look at the brain cam and see that it's turning
and watch what it's moving around. If it's not moving the right things
either the things are broken or they aren't in the right position or
the cam isn't in the right position.

keeping the start lever in "on" position, try rotating the platter by
hand a whole cycle and see if it changes something -- don't try too
hard.


This is a useful thing to do, but watch underneath while you're doing it.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Default Dual 621 turntable fix

Chuck wrote:
On Sun, 10 Feb 2019 15:25:48 +0100, Edi Zubovic edi.zubovic[rem
1 wrote:

Dual Steuerpimpel


Thanks for this information. If I can find a source for the idlers, I
might start repairing these again.


The last I saw, PRB still had idlers available for these things. If not,
Dave Dintenfass will occasionally put together a group buy on the Ampex
Mailing List to have new pinch rollers fabbed up... whoever he has doing
that can probably make you Dual idlers too.

The nice thing about the Dual idlers is that there are only a couple
different sizes for all their models.

But really.... the whole autochanger idea is so wrong...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
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Default Dual 621 turntable fix

Dana nedjelja, 10. veljače 2019. u 19:13:04 UTC+1, korisnik Scott Dorsey napisao je:
Chuck wrote:
On Sun, 10 Feb 2019 15:25:48 +0100, Edi Zubovic edi.zubovic[rem
1 wrote:

Dual Steuerpimpel


Thanks for this information. If I can find a source for the idlers, I
might start repairing these again.


The last I saw, PRB still had idlers available for these things. If not,
Dave Dintenfass will occasionally put together a group buy on the Ampex
Mailing List to have new pinch rollers fabbed up... whoever he has doing
that can probably make you Dual idlers too.

The nice thing about the Dual idlers is that there are only a couple
different sizes for all their models.

But really.... the whole autochanger idea is so wrong...
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."


I just have to correct you a bit Scott. The problem has got nothing with autochanger, Dual 621 doesn't even has this option. Problem is with automatic start so you don't have to manually put the needle on the record. And second, the needle won't get on starting position once it reach the end section of the record.
But I agree with you that autochanger is not friendly to records
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Default Dual 621 turntable fix

On 11/02/2019 5:13 am, Scott Dorsey wrote:
Chuck wrote:
On Sun, 10 Feb 2019 15:25:48 +0100, Edi Zubovic edi.zubovic[rem
1 wrote:

Dual Steuerpimpel


Thanks for this information. If I can find a source for the idlers, I
might start repairing these again.


The last I saw, PRB still had idlers available for these things. If not,
Dave Dintenfass will occasionally put together a group buy on the Ampex
Mailing List to have new pinch rollers fabbed up... whoever he has doing
that can probably make you Dual idlers too.

The nice thing about the Dual idlers is that there are only a couple
different sizes for all their models.

But really.... the whole autochanger idea is so wrong...


So is the idea of idler wheels on manual turntables. :-(
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