[g11]

Just bought a Dual CS 503-1 turntable from ebay. Works fine, but
tending to run slightly fast. Had a look at, and cleaned, the belt and
any bits it runs round to no avail. My simple mind tells me that a worn
belt would tend to run slow. Any suggestions as to how I might fix this
problem would be much appreciated.

[Mark D. Zacharias]

g11 wrote:
Just bought a Dual CS 503-1 turntable from ebay. Works fine, but
tending to run slightly fast. Had a look at, and cleaned, the belt and
any bits it runs round to no avail. My simple mind tells me that a
worn belt would tend to run slow. Any suggestions as to how I might
fix this problem would be much appreciated.

If it's a DC motor (probably is, since it is a later Dual model) there is
probably internal speed adjustments. Usually these are arranged in pairs.
That is, one each for the 45 rpm speed and one for the 33 1/3 speed. Often
there are small holes in the bottom of the player to insert a SMALL!
adjusting screwdriver. A very light touch is required or you could end up
ruining the potentiometer. All of this assumes there are no user speed
adjustments on the top side of the table. There is also a chance that the
33/45 select switch is flaky.

Mark Z.

[Mike Coatham]

"Mark D. Zacharias" wrote in message
. com...
g11 wrote:
Just bought a Dual CS 503-1 turntable from ebay. Works fine, but
tending to run slightly fast. Had a look at, and cleaned, the belt and
any bits it runs round to no avail. My simple mind tells me that a
worn belt would tend to run slow. Any suggestions as to how I might
fix this problem would be much appreciated.

If it's a DC motor (probably is, since it is a later Dual model) there is
probably internal speed adjustments. Usually these are arranged in pairs.
That is, one each for the 45 rpm speed and one for the 33 1/3 speed. Often
there are small holes in the bottom of the player to insert a SMALL!
adjusting screwdriver. A very light touch is required or you could end up
ruining the potentiometer. All of this assumes there are no user speed
adjustments on the top side of the table. There is also a chance that the
33/45 select switch is flaky.

Mark Z.

The OP didn't say where he bought it, so the T/table may be from Europe with
a 50Hz motor and he's using it in USA or Canada where 60Hz is the norm??
This would explain the fast running. If the above scenario is correct he'll
likely need to change the pulley, motor or both.

[Mark D. Zacharias]

Mike Coatham wrote:
"Mark D. Zacharias" wrote in message
. com...
g11 wrote:
Just bought a Dual CS 503-1 turntable from ebay. Works fine, but
tending to run slightly fast. Had a look at, and cleaned, the belt
and any bits it runs round to no avail. My simple mind tells me
that a worn belt would tend to run slow. Any suggestions as to how
I might fix this problem would be much appreciated.

If it's a DC motor (probably is, since it is a later Dual model)
there is probably internal speed adjustments. Usually these are
arranged in pairs. That is, one each for the 45 rpm speed and one
for the 33 1/3 speed. Often there are small holes in the bottom of
the player to insert a SMALL! adjusting screwdriver. A very light
touch is required or you could end up ruining the potentiometer. All
of this assumes there are no user speed adjustments on the top side
of the table. There is also a chance that the 33/45 select switch is
flaky.

Mark Z.

The OP didn't say where he bought it, so the T/table may be from
Europe with a 50Hz motor and he's using it in USA or Canada where
60Hz is the norm?? This would explain the fast running. If the above
scenario is correct he'll likely need to change the pulley, motor or
both.

This would only apply if it were an older Dual model with an AC motor. The
OP's turntable is a later Dual model with a DC servo motor.

Mark Z.

[g11]

Mark D. Zacharias wrote:
Mike Coatham wrote:
"Mark D. Zacharias" wrote in message
. com...
g11 wrote:
Just bought a Dual CS 503-1 turntable from ebay. Works fine, but
tending to run slightly fast. Had a look at, and cleaned, the belt
and any bits it runs round to no avail. My simple mind tells me
that a worn belt would tend to run slow. Any suggestions as to how
I might fix this problem would be much appreciated.

If it's a DC motor (probably is, since it is a later Dual model)
there is probably internal speed adjustments. Usually these are
arranged in pairs. That is, one each for the 45 rpm speed and one
for the 33 1/3 speed. Often there are small holes in the bottom of
the player to insert a SMALL! adjusting screwdriver. A very light
touch is required or you could end up ruining the potentiometer. All
of this assumes there are no user speed adjustments on the top side
of the table. There is also a chance that the 33/45 select switch is
flaky.

Mark Z.

The OP didn't say where he bought it, so the T/table may be from
Europe with a 50Hz motor and he's using it in USA or Canada where
60Hz is the norm?? This would explain the fast running. If the above
scenario is correct he'll likely need to change the pulley, motor or
both.

This would only apply if it were an older Dual model with an AC motor. The
OP's turntable is a later Dual model with a DC servo motor.

Mark Z.

Thanks for the replies folk. From the dual reference website, the motor
is a "tacho-controlled DC Motor". Despite taking what I could of the
turntable apart, no closer to finding any internal speed adjustments.
Any idea where they are likely to be situated? Nothing obvious on the
bottom of the player either. The turntable didn't cost much, but it's a
bit frustrating as it's noticeably fast.

[Mark D. Zacharias]

g11 wrote:
Mark D. Zacharias wrote:
Mike Coatham wrote:
"Mark D. Zacharias" wrote in message
. com...
g11 wrote:
Just bought a Dual CS 503-1 turntable from ebay. Works fine, but
tending to run slightly fast. Had a look at, and cleaned, the belt
and any bits it runs round to no avail. My simple mind tells me
that a worn belt would tend to run slow. Any suggestions as to how
I might fix this problem would be much appreciated.

If it's a DC motor (probably is, since it is a later Dual model)
there is probably internal speed adjustments. Usually these are
arranged in pairs. That is, one each for the 45 rpm speed and one
for the 33 1/3 speed. Often there are small holes in the bottom of
the player to insert a SMALL! adjusting screwdriver. A very light
touch is required or you could end up ruining the potentiometer.
All of this assumes there are no user speed adjustments on the top
side of the table. There is also a chance that the 33/45 select
switch is flaky.

Mark Z.

The OP didn't say where he bought it, so the T/table may be from
Europe with a 50Hz motor and he's using it in USA or Canada where
60Hz is the norm?? This would explain the fast running. If the
above scenario is correct he'll likely need to change the pulley,
motor or both.

This would only apply if it were an older Dual model with an AC
motor. The OP's turntable is a later Dual model with a DC servo
motor.

Mark Z.

Thanks for the replies folk. From the dual reference website, the
motor is a "tacho-controlled DC Motor". Despite taking what I could
of the turntable apart, no closer to finding any internal speed
adjustments. Any idea where they are likely to be situated? Nothing
obvious on the bottom of the player either. The turntable didn't cost
much, but it's a bit frustrating as it's noticeably fast.

I would just have to see it, or at least see a service manual for that
model. There may be a speed control board external to the motor, or there
may be an adjustment potentiometer accessible through the bottom of the
motor itself - though I doubt that somewhat.

There is also a chance the belt could be riding up on the motor pulley.

It's not a quartz-locked type, so I'm pretty sure there's a speed adjustment
in there somewhere...

If you are able to take any digital pics - you can e-mail them to:



and reverse the domain name.


Mark Z.

[Serge Auckland]

g11 wrote:
Mark D. Zacharias wrote:
Mike Coatham wrote:
"Mark D. Zacharias" wrote in message
. com...
g11 wrote:
Just bought a Dual CS 503-1 turntable from ebay. Works fine, but
tending to run slightly fast. Had a look at, and cleaned, the belt
and any bits it runs round to no avail. My simple mind tells me
that a worn belt would tend to run slow. Any suggestions as to how
I might fix this problem would be much appreciated.
If it's a DC motor (probably is, since it is a later Dual model)
there is probably internal speed adjustments. Usually these are
arranged in pairs. That is, one each for the 45 rpm speed and one
for the 33 1/3 speed. Often there are small holes in the bottom of
the player to insert a SMALL! adjusting screwdriver. A very light
touch is required or you could end up ruining the potentiometer. All
of this assumes there are no user speed adjustments on the top side
of the table. There is also a chance that the 33/45 select switch is
flaky.

Mark Z.
The OP didn't say where he bought it, so the T/table may be from
Europe with a 50Hz motor and he's using it in USA or Canada where
60Hz is the norm?? This would explain the fast running. If the above
scenario is correct he'll likely need to change the pulley, motor or
both.
This would only apply if it were an older Dual model with an AC motor. The
OP's turntable is a later Dual model with a DC servo motor.

Mark Z.

Thanks for the replies folk. From the dual reference website, the motor
is a "tacho-controlled DC Motor". Despite taking what I could of the
turntable apart, no closer to finding any internal speed adjustments.
Any idea where they are likely to be situated? Nothing obvious on the
bottom of the player either. The turntable didn't cost much, but it's a
bit frustrating as it's noticeably fast.

Just a suggestion, but some DC motors used on cassette decks have an
adjustment hole on the motor itself. This is obviously more relevant for
a single speed, but it is possible that the motor is set up correctly at
one speed, and the other speed is done as a straight voltage ratio. Not
very likely, I accept, but possible.

S.

S.