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Dual 1019 weak channel

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Dual 1019 weak channel

Postby bobdual » 23 Mar 2012 14:14

Appreciate your help with this: The bottom RCA OUT jack appears to have very weak output. The side that plays sounds great. Also tried two diff records. I have tried the player on two different amps and reversed the RCA IN on both tests with results pointing to the Dual. I removed and inspected the cartridge holder and gently bent the four contacts up to ensure good contact. The cartridge says "audio technica" but no model number that I see. My dad left me a Shure M55E cartridge also. Any thoughts? Thanks in advance.
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Re: Dual 1019 weak channel

Postby burlybryan » 24 Mar 2012 18:04

You're on the right track. On my 1019, I've had a flakey channel a few times. Once it was a bad solder joint at the RCA out (I soldered in some new ones) and every other time it was the contacts on the headshell. Bending them a bit helps (but don't break the little plastic tab!), but they also need to be cleaned with contact cleaner and either rubbed with an eraser or fine sandpaper to make them shiny bright. Also, if you haven't tried swapping in the Shure, it's a good way to eliminate the AT cart being the issue.
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Re: Dual 1019 weak channel

Postby mosin » 24 Mar 2012 21:43

The Dual 1019 is different from most turntables because it breaks the signal from the cartridge when the arm is not in the playing position. This is done by actuating contacts underneath the top plate. Unfortunately, it is a source of signal loss.

You most likely have dirty contacts at that point. Lift the turntable up, or flip it over, so you can see the contacts. Clean them with an appropriate contact cleaner, and you should be set for awhile. I would place the odds at 90% on this being the problem.
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Re: Dual 1019 weak channel

Postby Doug G. » 25 Mar 2012 17:09

No, the table doesn't break the signals from the cartridge during a cycle. It shorts the signals out. So a signal loss will never be caused by those contacts being dirty or pitted.

The only thing that will happen is that the signals will still be active if the contacts are bad.

It would be a poor design to rely on contacts to pass the signals during play.

On a 1019, by far the most common problem with signal dropout is the contacts in the headshell and cartridge clips being oxidized on the inside surfaces. If the problem proves not to be the cartridge or the cables, those are the things on which to concentrate.

Doug
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Re: Dual 1019 weak channel

Postby bobdual » 25 Mar 2012 22:12

Thanks gentlemen. I changed out the cartridge. Played fine except the weak channel problem continues. How liberal or not should I be with contact cleaner? I assume this is a spray I can get at Radio Shack. I noticed that the clips that attach to the cartridge pins need cleaning. Are they fair game? I'll remove the cartridge before cleaning the contacts on the cartridge holder. And what about the contacts on the tonearm? I assume I have to spray "up" to get at them. Even if I c**k the entire deck on its back edge it appears awkward. Any hints to contact cleaning etiquette? Also, should I use the cleaner on the RCA jacks? Thanks much.
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Re: Dual 1019 weak channel

Postby gg383 » 26 Mar 2012 07:43

Bob, there is one main thing, BE CAREFUL, if you mess up one of the little wires or break a contact off a headshell you just created a new set of problems. Radio Shack does have a couple of sprays 64-4315 Contact-Control Cleaner & Lube and 64-4345 Precision Electronics Cleaner, that has a removable brass brush on the spray outlet. Last time I bought 'em was a few years ago and they were about $12.00 each then. I do prefer the 64-4315 that used to be called TV Tuner Cleaner back in the old days of the barrel TV Tuners. First can of that I bought was $1.99. It's a little cleaner than the second one that seems a little oily . You might want to try an eraser first tho, lot cheaper. Auto parts stores might have products that give you more for your money too, both Shack products are in cans that are less than 6 oz. If you get the spray I'd spray all contact areas, just put some old rags around or under things to protect the paint and finish, remove the stylus and then you don't have to take the cartridge off the headshell carrier, just cover the stylus end of it. On the Dual output and the pre-amp receiver input clean the connections too. Spray it on Q-Tips to work grungy areas. If the center pins on the RCA plugs are grungy or pitted junk them. If they're RCA on both ends they're dirt cheap, or more depending what you want. If they're the 4mm clips on the Dual end then they're pricy for sure. Good Luck, Glenn
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Re: Dual 1019 weak channel

Postby Doug G. » 26 Mar 2012 23:13

Another thing. The contacts and cartridge clips on old Duals are silver plated and it turns black and becomes nonconductive. Spraying with cleaner will do nothing to fix it. You have to physically remove the oxide coating with fine abrasive to restore conductivity.

The spray cleaners are fine for removing dirt and gunk from contacts but don't help with oxidation.

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