RF Noise

 

Bronze Member
Username: Snapcat

Post Number: 58
Registered: Oct-07
I've been struggling with what seems to be a Radio Frequency (RF) pop noise triggered by various electical switches in our home (determined after many helpful emails with the Bryston folks). One is the HVAC, another the refrigerator. The pops were loud thru the Bryson until I moved it and used a different outlet. It still exists thru the Bryston and thru an Outlaw Audio M2200 used for a center channel (fairly quiet now).
I had a Rotel HT amp before and experienced no such pop noises ever. It was in the same location/outlet as the Bryston when bad pops occurred.
I have been using unbalanced (RCA) connections for all.

Question: Are fully balanced amps, which are connected in an unbalance setup, more susceptible to RF than unbalanced amps?
I understand that the Rotel has balanced connections but isn't fully balanced....
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 12734
Registered: May-04
.

Unbalanced operation of the line level signals shouldn't cause a problem with RF compared to balanced lines. The Bryston might not have the same RF filtration in its power supply that was designed into the Rotel. Give Bryston a call and discuss the issue with them.
 

Platinum Member
Username: Nuck

Post Number: 10377
Registered: Dec-04
Wrap arouns RF suppressors or ferrite rings from Rat Shack might quell the noise.
 

Bronze Member
Username: Snapcat

Post Number: 59
Registered: Oct-07
Thanks Jan and Nuck,

I'll continue to pursue discussions with Bryston. They've suggested that I move to balanced connections - and I plan to do that. Mainly, I'm reallly curious why the Rotel never did it.

I'll be poking around the Radio Shack also - thanks.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 12738
Registered: May-04
.

The Rotel HT receiver was a mass market product designed to minimize user problems where possible. Some manufacturers install RF/EM filters in their power supply to keep customers from bringing back components that really have no problems, just problems in that particular installation. As you move to companies like Bryston the manufacturer might assume you have your own form of filtration and doesn't care to double up since filters aren't always a good thing for sound quality. Moving to balanced lines will minimize common mode noise such as line noise caused by a motor running. What I unuderstand you are hearing is the switching noise as the motor starts up. Balanced operation may take that noise down a notch but I don't see it removing the problem, however, Bryston knows their product better than I do.


The best way to resolve the issue, IMO, is to have an electrician install dedicated lines to your listening room.




.
 

Silver Member
Username: Magfan

USA

Post Number: 255
Registered: Oct-07
Dedicated power is a very good idea.

PS Audio sells a line of outlets.
I have the Soloist on its own 20amp breaker feeding the power amp and sub only.
The Soloist is a single duplex outlet fitted into a double box and can be installed by any competent electrician.
 

Bronze Member
Username: Snapcat

Post Number: 60
Registered: Oct-07
Thanks Jan and leo.

I can definitely get a dedicated line with a separate breaker. Any further suggestions there? 20amp sounds good for future flexibility.

All that I've read about RF indicates that you can't really block it, that you need to eliminate the source. This is not the classic RF that I've read about - it is a switching pop from other electrical items. It is very slight in volume now. It made the dog jump before.

I've not heard it thru the NAD either, but it's never been on the 'bad' outlet.
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 12740
Registered: May-04
.

The "pop" you are hearing is more likely EMI - electromotive interference. This sort of noise is distributed through the electrical system of your house and every house tied onto the transformer out back on the pole. There are devices to mount on the refrigerator to minimize noise but they are not cheap. The HVAc is more of a problem due to the excessive amount of current that starts everything going.
 

Platinum Member
Username: Nuck

Post Number: 10381
Registered: Dec-04
Have a look in your home and be sure the mains are gounded properly to the water supply pipe and the gas lines. Also bond to a large copper pipe.
 

Bronze Member
Username: Snapcat

Post Number: 63
Registered: Oct-07
Thanks all. Will do.
« Previous Thread Next Thread »



Main Forums

Today's Posts

Forum Help

Follow Us