[easycure]

Hi, newbie question here: anyone knows a good way to shield desktop headphone amp from picking interference from monitor? I am hearing cracks and pops, digitally sounding noises - when I'm maximizing or moving a window on screen. I'm also picking hard drive spin noises. My amp is situated about 50cm from monitor and computer. Is moving the amp away from the desk the only option?

 

[jordanross]

Google Faraday cage...

 

[easycure]

Ok - faraday cage....faraday cage... maybe putting my amp inside microwave oven will do the trick?

 

[Testament]

yeah i think a faraday cage is the best bet. But for me i thought i was getting interference in my amp, but it was actually the tubes burning in. they sounded crackly after putting a new power tubes, then mellowed out after a week or two.

 

[Golden Monkey]

Quote:

Originally Posted by easycure /img/forum/go_quote.gif Ok - faraday cage....faraday cage... maybe putting my amp inside microwave oven will do the trick?

LOL...yup, that'd do the trick. Just don't make popcorn at the same time.

One serious question though...is your amp and computer pluegged into the same outlet or power strip? If so, try moving one or the other, or getting some sort of power conditioner and see if that helps.

 

[Dept_of_Alchemy]

Most likely it's your tubes picking up the interference, a pair of mil-spec tubes (like the Mullard M8100) often will solve the problem.

 

[easycure]

I have bought military spec mullards a couple of days ago. Still waiting for them to arrive. If they will help than this will be the simple solution im looking for. Thanks for advice guys!

 

[hohum]

Out of curiousity, are you connecting the amp directly to the analog out of your soundcard? If so then that's probably why, I had the same issue myself (although I don't have the same amp). I bought a DAC in the end to get around the problem.

 

[easycure]

I have an usb DAC (well sort of... Native Instruments Audio Kontrol). When i connect the headphones directly to it there is no audible interference.

 

[hohum]

Yeah, I had the same issue pretty much:

1. Connect headphones directly to soundcard = no audible interference
2. Connect soundcard to headphone amp = audible noise when moving mouse, resizing windows, etc

Really annoying. I guess using an amp just makes the noisy power circuitry within the PC environment more apparent (i.e. amplifies it to an audible level, shocker!

) Using optical out to external DAC resolved it for me, purely down to the electrical isolation. Anyway, see how you get on with your new tubes first... don't be too upset if they don't help, though.

 

[easycure]

I think its the amp. I also use that DAC to feed sound to active monitor speakers and they dont pick anything at very loud amplification level - they must be shielded pretty good i guess.

 

[Golden Monkey]

See my earlier post...are they plugged in at the same location?

 

[easycure]

All is plugged into the same power strip... i will try plugging the amp somewhere else and will let you know if that helped.

 

[LeBuLLeT]

golden monkey I was wondering about your previous post. I know if you put a computer and audio equipment in the same power strip it will decrease audio quality because of DC in the line or something like that. Well I don't know if this makes sense but as you may know there are 2 outlets from one socket(white box) in a typical home. What if I was to change all my audio equipment to the bottom outlet and then my other electrical equipment to the top one? Would that help or do I have to move it to a different socket or just different room to get the best out of my equipment?

 

[Golden Monkey]

I've noticed noise when I share a dual outlet, yes, but it depends on ther way the outlet is constructed, I think. They share the same incoming AC, but the outlets should be separate from each other. I had a dedicated line installed to our home office for the PC from the electrical panel, and it's a quad outlet. I have the UPS for the PC plugged into one of the outlets, and on the other pair I have my audio equipment's power conditioner plugged in. Everything in my audio chain is powered from the Furman conditioner, and this way I've got no line noise or interference. Going old skool (lol) I've shared outlets with a computer and audio equipment in the past, and yes, I've definitely heard noise like easy's mentioned. Before I had any power conditioning or fancy power lines run, switching to separate outlets pretty much took care of the problem. I still had noise if I had all audio on one outlet and all PC on the other in a dual outlet, like you mentioned, but the wiring and electrical stuff in genereal at that apartment was pretty old and cheap, so I'm not suprised.