# Turntable Interference (power problem? please help!)



## Jemsic

I'm hearing interference (an electric hum) while listening to my Gemini TT-02 turntable. I can't figure out what my problem is, but I suspect it has to do with the power - as the interference sounds like an electric hum. It's grounded to the ground pin on the amp, and that reduces the hum considerably - but its still present.

 One noticeable thing is that when certain lights throughout the house are turned on, the hum increases. Some lights don't do a thing, while other lights GREATLY increase the hum.

 Please help me diagnose and fix this, guys. I LOVE listening to my vinyl, but this hum makes listening almost unbearable.


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## trains are bad

Try wiggling, cleaning or tightening the little wire clamps that go on the cartridge pins.


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## 65535

Get a filter for your turntable. (inline power filter)


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## Jemsic

Hmm, a power filter sounds like the kinda thing I need.

 Any recommendations on what I should use? I have no idea what to look for. I did some google searches and became quickly confused at all the different kinds they have.


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## Jemsic

Update:

 I bought 2 of these
http://www.radioshack.com/product/in...entPage=search

 they don't seem to do a thing. But then, I just read a customer's review of it and they said that the specs suck, and it doesn't filter out the line of typical noise.

 Do I need a better one, or something entirely different? - because these didn't fix the problem.


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## Vul Kuolun

You're entirely on the wrong track.

 Using a line filter does nothing than filtering the power that drives the motor, which doesn't have the slightest effect on the music signal.
 Edit: Not too sure about that one anymore, as i saw that particular tt seems so be some kind of all-in-one-swiss-pocket-knife-kinda-thing.

 But first, make sure all your connections are correct. Then make sure all your components are plugged in the same outlet.
 BTW, what kind of phono-preamp are you using? 
 Are there any transformers (Halogen-lights or other components) nearby (the cartridge or the pre)?
 You can also try to use another ground, for example connecting the ground wire to a radiator or water supply line.

 Is there a tuner or tv connected to your setup? Try disconnecting the antenna(s).


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## Jemsic

I am using the phono preamp that is built into my receiver (model listed in my sig). 
 All my connections are correct, and I double-checked the cartridge connections to the headshell (they seem to be perfectly clean and strongly connected). 
 All my components (the TT and receiver) are plugged into the same outlet. 
 There are halogen lights nearby, yet none of them are on.
 I tried grounding it to many different sources - all giving me the same result.
 There is a tuner built into my receiver, yet that option is not selected and there is currently no antenna attached.

 Thanks so much for your replies! 
	

	
	
		
		

		
			




 I'm going to try moving the whole setup to a different location in the house to see if anything has changed.


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## Vul Kuolun

Damn. Good luck then.


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## Jemsic

Well, I lugged all that equipment all over the house... and no luck.
 I tried it in the living room, the kitchen, my room upstairs, and the bathroom upstairs... nothing.

 From what I can tell, it gives the same amount of hum in every room of the house.

 I'm starting to get really discouraged 
	

	
	
		
		

		
		
	


	




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 Any more suggestions?


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## Jemsic

Update:

 I'm currently thinking that the standard rca (left, right, ground) cable that came with my turntable is causing the problem. If I move it around, I get different levels of interference. I'm going to see if I can find (or build) a better-shielded cable.


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## Jemsic

SUCCESS!!!!!!!! 
	

	
	
		
		

		
		
	


	










 My dad (old radio expert) soldiered up a coax cable with rca ends for me. It's heavily shielded, and now I can turn the volume up all the way without getting any hum whatsoever!!!

 Ahh, words can't describe how happy I am right now 
	

	
	
		
		

		
		
	


	




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## infinitesymphony

Great! I'm anticipating a similar tonearm cable upgrade for my own recently-purchased turntable. Where did he buy the cable, and how did he incorporate the ground connector?


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## Jemsic

I have no idea where he bought the cable, he just had it left over from probably 30 years ago. He said its just a coaxial cable (I'm new to all this so he's teaching me). I watched him cut the end off and soldier the inside wire to the inside, and the outside wire to the outside piece (I don't know if I'm describing this right, but a coax cable has a separate shielded cable outside of an inner one). Maybe they're not exactly RCA plugs, I don't know if they are or not. But I'm sure that they fit into the standard RCA plugs on all consumer electronics. The plugs are all heavy and gold-plated.

 He didn't incorporate the ground into the cable, but made a separate ground with those little hook ends crimped on.

 I just listened for a little more than an hour, and MAN does it sound good! No more interference! I recommend this type of cable for ANYBODY.


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## infinitesymphony

Hmm, good idea... I guess the ground cable could be separate.

 Consider yourself a "cable believer."


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## Jemsic

That's what the cable looks like. I really love this cable, but you'd probably be surprised to find out that they're dirt cheap. I've found coax cable online for as low as 15 cents/ft. Don't spend alot on store-bought cables, make your own!


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## infinitesymphony

Thanks for the picture / diagram.

 To what was he soldering the outer braid? I've never seen the guts of a modern turntable before, so I wonder how difficult it was to solder the cable inside. I don't s'pose you have a sequence of pictures detailing the whole process...?


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## Jemsic

No, he didn't soldier anything to the turntable. He just soldiered plugs onto some coax cable.

 Here's a diagram I made to help:





 Now of course, he didn't soldier them to the outside of the plug where the lines I drew point - but on the inside, on the reverse side of the plug that you can't see.

 I hope this helps!


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## infinitesymphony

Oh, okay, so really it was just a matter of making some new cables. Most turntables have the coaxial cables wired/soldered directly to the tonearm instead of having female RCA-type outputs on the back. It's probably nice to have the option of just throwing on a different set of cables.


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## Jemsic

Ah, well if your turntable has the cables wired directly to the turntable then they are probably at least coax. The cables that came with my turntable were just cheap chinese wire, like the kind used to makes the cords in $10 headphones. That's why they picked up so much interference.


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## Fitz

If you think RG59 is "heavily shielded", you should check out RG6 quad.


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## Jemsic

heh, well I'm not sure what mine is. That picture is just what I found on wikipedia, its not mine.

 All I know about mine is that I can turn the volume on the amp all the way up without hearing any interference whatsoever.

 EDIT: well, when the volume gets to its highest, I can start to hear a VERY faint amount of the interference I mentioned... but I could never listen that loud. I would surely blow out my headphones if I tried to play any audio with the volume that high.


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## infinitesymphony

There are interconnects that are better for audio transfer (better conductor, shield, construction, etc.), and if you stick around this website long enough, you'll probably be interested in some. Any decent cable should avoid interference and hum, but better cables will give you improved frequency response. Obviously uber-expensive cables aren't really worthwhile for most setups; my personal limit is ~$35 for a pair of LC-1s from Blue Jeans Cable.

 But let's not turn this into a cable discussion.


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## Jemsic

Fair enough 
	

	
	
		
		

		
		
	


	




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