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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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5th Jun 2017, 12:15 am | #1 |
Hexode
Join Date: Jun 2012
Location: Aabenraa, Denmark.
Posts: 262
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Dual 1218 missing sound
Hey everyone, everything is mounted fine in the turntable but something are causing it to completely lose audio on the right channel side. What's the cause? the little switch thing is my suspect, its because the sound is really thin and you hear some humming going on, yet the left audio channel is fine, how can i work around it? im not great at soldering.
Last edited by Nic-15fl; 5th Jun 2017 at 12:38 am. |
5th Jun 2017, 1:45 am | #2 |
Heptode
Join Date: Dec 2016
Location: Sheffield, South Yorkshire, UK.
Posts: 539
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Re: Dual 1218 missing sound
Have you eliminated the cartridge as a cause?
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5th Jun 2017, 3:37 am | #3 |
Hexode
Join Date: Jun 2012
Location: Aabenraa, Denmark.
Posts: 262
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Re: Dual 1218 missing sound
Yes, I have isolated the cause, it's not the cartrigde, because it worked fine last weekend.
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5th Jun 2017, 9:05 am | #4 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,844
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Re: Dual 1218 missing sound
Is this one of the ones with a removable headshell/cartridge carrier? These can cause no end of problems.
See this thread about a similar-ish Dual: https://www.vintage-radio.net/forum/...d.php?t=126757 |
5th Jun 2017, 11:55 am | #5 |
Heptode
Join Date: Dec 2016
Location: Sheffield, South Yorkshire, UK.
Posts: 539
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Re: Dual 1218 missing sound
The best way is to use the buzz test. You connect it up to the amp and work backwards. Touching the Right hand channel audio circuit with either a screw driver or your finger. As long as you don't touch power supplies you will be fine. The circuit should buzz if it's working. You should hear a buzz from the amp's pre-amp circuit first. That proves it's working inside the amp. If you don't have a buzz there, then there's nothing wrong with the turntable and you have a faulty pre-amp inside your amp. This will NOT affect any other part of the amp, such as the radio if it has one.
The buzz test can be used on that switch you mentioned. If one side buzzers and the other doesn't when closed, then the switch has gone. Just to make certain you have not got a weak connection to the cartridge, take the right channel connection off. Then buzz test it. If it does buzz then either the connection is bad or even though it was working "last weekend" it ain't now! Famous last words that all technicians here that... "It was working..." My favourite quote is from one of the TV magazines. "It was working fine till it blew up". |
5th Jun 2017, 5:07 pm | #6 |
Hexode
Join Date: Jun 2012
Location: Aabenraa, Denmark.
Posts: 262
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Re: Dual 1218 missing sound
I did something close to that, doing the buzzing test and it was gone in the right channel.
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5th Jun 2017, 9:46 pm | #7 |
Dekatron
Join Date: Nov 2008
Location: Whittlesey, near Peterborough, Cambridgeshire, UK.
Posts: 3,761
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Re: Dual 1218 missing sound
Swap the red (R+) and white (L+) cartridge wires over and try again. If the right hand channel now works, but the left is dead, then your cartridge is faulty. No need to swap the two negatives (black and green), as they are joined at the terminal block anyway.
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6th Jun 2017, 7:13 am | #8 |
Hexode
Join Date: Jun 2012
Location: Aabenraa, Denmark.
Posts: 262
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Re: Dual 1218 missing sound
Well, its completely gone on that little mounting point, the cartrigde itself is ok.
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6th Jun 2017, 2:33 pm | #9 |
Dekatron
Join Date: Nov 2008
Location: Whittlesey, near Peterborough, Cambridgeshire, UK.
Posts: 3,761
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Re: Dual 1218 missing sound
What has gone, and what little mounting point?
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6th Jun 2017, 2:41 pm | #10 |
Hexode
Join Date: Jun 2012
Location: Aabenraa, Denmark.
Posts: 262
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Re: Dual 1218 missing sound
I was trying to talk about at the meeting point with that metal part on the tone arm where the pin meets, its noting to do with the cartrigde, i get no sound when doing the buzzing test on the right channel, only a thin sound with a noitcebel humming, i need to bypas the wire, wich im terrible at..
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6th Jun 2017, 4:01 pm | #11 |
Heptode
Join Date: Dec 2016
Location: Sheffield, South Yorkshire, UK.
Posts: 539
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Re: Dual 1218 missing sound
Would this help the problem?
Head shell on Amazon I am still concerned that the loss of sound might be before the 4 pin link. Just do a buzz test on where the 4 pins go in. If you hear no buzz on the right then the problem is before the headshell. |
6th Jun 2017, 5:46 pm | #12 |
Hexode
Join Date: Jun 2012
Location: Aabenraa, Denmark.
Posts: 262
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Re: Dual 1218 missing sound
Thats what i would hope for, because im talking about this mounting point.
Last edited by AC/HL; 6th Jun 2017 at 7:34 pm. Reason: Image uploaded |
10th Jun 2017, 11:53 am | #13 |
Hexode
Join Date: Jun 2012
Location: Aabenraa, Denmark.
Posts: 262
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Re: Dual 1218 missing sound
I can clearly mark out its not the amplifier, and it is the dual itself haveing audio trouble, i tested with another stereo player i have and that one is in stereo.
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