[groovizintheheart]

  I've recently started to notice an RF noise at all dB levels which is really annoying.  Has anybody come across issues with RFI with this amp? what did you do to resolve it. Thanks.

 

[john57]

It depens on what kind of noise you are getting like hiss, hum or buzz are caused by differnt things. I did have RF interface that was coming from the computer sound card DAC and only when the driver for the sound card gets loaded.

 

[feifan]

No, never had this problem. Have you tried a different outlet in a different room? Is there another power supply (from other equipment) close to the Phonitor? Please keep us posted on this problem.

 

[feifan]

No, never had this problem. Have you tried a different outlet in a different room? Is there another power supply (from other equipment) close to the Phonitor? Please keep us posted on this problem.

 

[.Sup]

I have Auditor and its dead silent (balanced cables- XLR)

 

[groovizintheheart]

Quote:

No, never had this problem. Have you tried a different outlet in a different room? Is there another power supply (from other equipment) close to the Phonitor? Please keep us posted on this problem.

Yes, my guess is the noise might be seeping from the power source at the wall.  I have tried outlets farthest away from the outside wall but have had no luck.   Is it possible the headphone cord might be acting as an antenna?  I bought ferrite chokes to attenuate this noise.   I will post the results with this solution. 

 

[groovizintheheart]

So, a quick update here... the interference wasn't coming from the power.  I bought a ferrite choke and put it close to the unit to no avail.  I do see the noise attenuate when I touch the headphone connector at the amp input so my best guess is the noise is being picked up at the headphone cable (AKG cable is very thin, probably doesn't have very good shielding).
 
I received an e-mail from who I believe to be SPL's CEO.  He was kind enough to give me a quick explanation of how they were unable to fix a problem they've observed in a studio where a short wave radio station was close by and caused the RF interference.  He suggested either using a Faraday cage or moving someplace else...  I will have to try switching cables on the 702 as this seems to be where the noise is picked up.

 

[khaos974]

Try another headphone? try it with another wall socket? in another room? at your workplace? with balanced inputs?
That should at least help you isolate the origin of the problem.

 

[John Buchanan]

I had an intermittent soft crackly-like sound - drove me crazy. Finally changed the headphone extension cable from the Beyerdynamic to a Mogami Gold Ext 10 and the problem disappeared.

 

[feifan]

I had an intermittent soft crackly-like sound - drove me crazy. Finally changed the headphone extension cable from the Beyerdynamic to a Mogami Gold Ext 10 and the problem disappeared.

John, thanks for this solution. Another option for those experiencing this problem. My Phonitor (model 2730) is still running beautifully with no problems. I have it linked to a PSA Digital Link III DAC. My heaphones are Sennheisers: HD650 and HD800.

 

[John Buchanan]

I had an intermittent soft crackly-like sound - drove me crazy. Finally changed the headphone extension cable from the Beyerdynamic to a Mogami Gold Ext 10 and the problem disappeared.

I was wrong - the problem reappeared, but became less frequent when a neighbour moved out (we live in a block of townhouses). I now suspect the Phonitor may be sensitive to wireless router frequencies.

 

[John Buchanan]

I was wrong - the problem reappeared, but became less frequent when a neighbour moved out (we live in a block of townhouses). I now suspect the Phonitor may be sensitive to wireless router frequencies.

On advice, I also tried placing a ferrite snap-on bead as close to the wall AC 3 pin plug as possible. It's a very cheap, easy and reversible solution. It appears to have succeeded in controlling the soft crackly noises, that intermittently accompanied the music, completely so far. Previously, I'd had them at the IEC plug end without much success - live and learn. I'll update if this intermittent fault reappears, however. That Phonitor really is a great headphone amp.

 

[bvhme]

I have recently bought a Phonitor X and it works swell.

However I have a Beyerdynamic XLR audiophile cable, and it has this crazy interference as well! I'm guessing it is the same cable as yours!

I love that Beyerdynamic cable though, sad it behaves this way.

I've recently started to notice an RF noise at all dB levels which is really annoying. Has anybody come across issues with RFI with this amp? what did you do to resolve it. Thanks.

Did time introduce another solution or does this cable just not work with the Phonitor?

 

[feifan]

bvhme, thanks for this insight. To those having this RFI/EMI problem: You might want to check out these potential sources:
Cellular networks
Wi-Fi and Bluetooth devices
Power supplies
Electric motors and generators
Transmitters
Transformers
Electric blankets
Electric bug killers
Baby monitors
Microwaves
Heaters
Lamps

 

[bvhme]

bvhme, thanks for this insight. To those having this RFI/EMI problem: You might want to check out these potential sources:
Cellular networks
Wi-Fi and Bluetooth devices
Power supplies
Electric motors and generators
Transmitters
Transformers
Electric blankets
Electric bug killers
Baby monitors
Microwaves
Heaters
Lamps

Thanks Feifan! I have this problem with no other cable or amp combinations, so I'm afraid it's not just one of those. Also changing the cable position didn't change the interference, making me doubt it's the cable acting as an antenna in the first place.