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Turntable Susceptibility to RFI

Audiofire

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Does residential radio-frequency interference cause audible problems for a turntable setup, especially with a WiFi router or mobile phone a few meters away? The cartridge and tonearm would be places that are affected if there is any issue, especially with a sensitive moving coil cartridge. Would it make sense to use aluminum foil on top of the whole dust cover?

For turntable noise, it has been considered elsewhere that WiFi and cell phones can be a significant problem:
"Noise can be injected either via magnetic induction or from electric fields. And not just into the phonostage; noise can be coupled into cables, tonearm, or the cartridge itself.
"Try to isolate the phonostage. Remove all WiFi routers, tablet, laptops, and cell phones that were nearby."

"Position the turntable at least a few feet away from electronic devices - especially high power electronics and devices with wireless transmitters. TVs, routers, cordless phones, and even light dimmers are common culprits."

So how paranoid do you think one should be about this, and specifically how relevant it is to equip a turntable with a kind of suspecting tinfoil hat in the form of aluminum foil shielding that covers the transparent lid?
 

Balle Clorin

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1.Never use A lid on A turntable .. when playing .. catchtes and amplifies and inject vibrations into the turntable.
2 Never use Grado cartridges
3. Keep phonoleads and RIAA amp away from any transformer.

Then you avoid noise
 
OP
Audiofire

Audiofire

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Well it should be easy to find out if there is interference. Play a record at normal volume. Stop the turntable or lift the arm. Then turn on these new age components and see if the background noise changes.
Yes, I was interested to know about experiences from others.

1.Never use A lid on A turntable .. when playing .. catchtes and amplifies and inject vibrations into the turntable.
And what are experiences others have had with this? I believe that the miniscule air vibrations from the microgrooves will have no audible impact on the cartridge, except for systems that are not worthy to be called hi-fi.

Vibrations transmitted through the floor is another matter, so I use enough layers of rubber mats to remove excessive vibration mostly caused by loudspeakers.

This thread is for sharing personal experiences with audible problems from RFI, and by now for microphony caused by dust covers.
 
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Doodski

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I have not experienced RF interference like you ask about although I have had a turntable/bad amp that picked up aviation radio chatter. The fault was the amplifier. Replaced the amp and the issue went away. :D
 

antennaguru

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IME the biggest phono RFI culprit is typically interference from the smartphone in your own pocket due to your own smartphone's close proximity to your turntable and phono stage when you're putting on or flipping a record - if you're home is far away from the nearest cell site. OTOH if your home happens to be pretty close to the nearest cell site then your smartphone, which continually is updating apps and operates under loop transmit power control dictated by the cell site so that all smartphones on that cell site sector are received at the same amplitude, will be operating at very low transmit power which is unlikely to cause phono RFI. The best cure for most people is to keep your smartphone far from your phono system (or live very near a cell site).

The wires that connect the phono cartridge to the tonearm wiring are both typically exposed and unshielded. They make a great antenna for receiving RFI.

Sometimes a phono stage can be susceptible as well, depending upon how it's constructed.

When there is a fire or police station near your home, or your home is along a flight path, then the high power transmitters at the ground station or in the various vehicles passing by can affect your phono system as well. This is primarily because a phono system is amplifying the extremely low amplitude signal from the phono cartridge - just under 5mV from a high output cartridge, and under 0.5 mV from a low output cartridge.

It goes without saying that any wireless router should be positioned well away from your phono equipment.
 

Blumlein 88

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I don't know about the TT itself as much as the phono stage as it is where the gain is. In one case a friend started having intermittent issues with his phono. He was using a tubed phono stage which may have made it more prone to picking up RFI. Even though it was enclosed on all sides by the aluminum case with a vented cover having small holes for ventilation. I ended up attaching third pin ground to some foil taped to a notepad. Found a place that stopped the problem. He had moved some stuff around, and was using a Mac Mini for some music. It was sitting on an adjacent shelf about 1 foot away. The old ones had an internal power supply and that was apparently the issue. The grounded foil placed between them stopped the phono problems. He later moved his gear around placing the Mini 6 feet away where it was no problem.

As for dust covers, you can put a record not spinning on, drop the needle, and play music from another source. Record the phono output and hear faintly such music. This with no dust cover. If you do the same, with a dust cover it is worse. Is it enough to be audible? Don't know. I've done this with some well made very well isolated TT setups.
 

JeffS7444

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Yes, I was interested to know about experiences from others.

And what are experiences others have had with this? I believe that the miniscule air vibrations from the microgrooves will have no audible impact on the cartridge, except for systems that are not worthy to be called hi-fi.

Vibrations transmitted through the floor is another matter, so I use enough layers of rubber mats to remove excessive vibration mostly caused by loudspeakers.

This thread is for sharing personal experiences with audible problems from RFI, and by now for microphony caused by dust covers.
There's no need to speculate, you can hook up the turntable to a real time analyzer, lower the stylus onto a stationary groove, and see for yourself what effect the dust cover and isolation products have. Chances are, it will be pretty obvious!
 

watchnerd

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I have a WiFi mesh access point about 4.5 feet from my TT, and about 2 feet from the phono inputs on my amp.

No issues.
 
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Audiofire

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There's no need to speculate, you can hook up the turntable to a real time analyzer, lower the stylus onto a stationary groove, and see for yourself what effect the dust cover and isolation products have. Chances are, it will be pretty obvious!
I will set up an experiment, just wanted to collect some information first to know how paranoid one should be about such things (and this thread obviously confirmed that there is possibly a significant problem).
 
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