[userlander]

I moved my shanling to be my desktop amp, and it's picking up a lot of noise from all the computers, monitors, routers/switches, etc. in the power strips. What's the best thing to get to filter out or suppress all that noise?


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Edit: I think now it's actually the USB dac. I tried all 4 USB ports on my motherboard, but they all caused the same noise. It does sound like some computer noise as opposed to electrical line noise. What can I do about it?
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gratuitous pic:

 

[fatcat28037]

I doubt a power conditioner will be much help. With the Amp on and wearing the phones I'd try rearranging equipment and listen to what happens. Just moving the amp away from the router may do the trick.

 

[MrGreen]

If wireless signals are a huge issue, you should be able to buy a faraday cage for your gear. Otherwise I'm not too sure.

 

[powerslave]

Which usb dac are you using, the vdac or hotusb1? I have a hotusb1 and never had any noise issues from either my desktop or laptop. Is this a desktop or laptop? I have heard of issues with laptop usb ports picking up noise from laptop power supplies. What are you using to play from your pc?

 

[userlander]

Quote:

Originally Posted by powerslave /img/forum/go_quote.gif Which usb dac are you using, the vdac or hotusb1? I have a hotusb1 and never had any noise issues from either my desktop or laptop. Is this a desktop or laptop? I have heard of issues with laptop usb ports picking up noise from laptop power supplies. What are you using to play from your pc?

It's the hotusb1 on a desktop pc. I didn't have time to hook up my v-dac and see if that also had noise, hopefully I can try that tomorrow. The hotusb worked perfectly with my laptop.

 

[powerslave]

Interesting, could be something with your desktop usb perhaps? What version of windows?

 

[userlander]

Quote:

Originally Posted by powerslave /img/forum/go_quote.gif Interesting, could be something with your desktop usb perhaps? What version of windows?

It's arch linux, actually.

But now I'm not so sure again. I plugged the headphones directly into the dac (duh - don't know why I didn't do that before) and there is no noise from there. Unless the amp is just amplifying it to more audible levels (it does increase with volume increase). But it's pretty black directly into the dac. So I guess it must be a line/power ground loop kind of problem. Totally annoying!

 

[powerslave]

Hmm, if i remember correctly, the hotusb1 doesn't have rca out's so you are using a mini to rca to connect to the shanling? Are you maxing the hotusb1 volume when you do this?

 

[userlander]

yes, mini to rca. hotusb1 has no volume control, so I guess it's maxed by default.

 

[powerslave]

Interesting. Not sure about linux but in windows you can control the volume using the windows volume slider. Is something similar possible with linux? I'm just trying to rule out that your driving the headphone out of the hotusb1 to max volume and then amping that with the shanling. That could conceivably cause distortion but not sure how audible that would be. When you just use the hotusb1, where do you control the volume?

 

[userlander]

Quote:

Originally Posted by powerslave /img/forum/go_quote.gif Interesting. Not sure about linux but in windows you can control the volume using the windows volume slider. Is something similar possible with linux? I'm just trying to rule out that your driving the headphone out of the hotusb1 to max volume and then amping that with the shanling. That could conceivably cause distortion but not sure how audible that would be. When you just use the hotusb1, where do you control the volume?

No, of course it's controlled by a software mixer. When you said the volume of the dac, I thought you meant a physical volume control like on the nuforce usb dac, for example. But I can move the PCM slider on the mixer up and down - no noise at all through the dac.

 

[powerslave]

Ok, and when you connect the dac to your amp, do you max that volume on the pc, or keep it lower and raise the volume on the amp?

 

[userlander]

Quote:

Originally Posted by powerslave /img/forum/go_quote.gif Ok, and when you connect the dac to your amp, do you max that volume on the pc, or keep it lower and raise the volume on the amp?

A little of both, actually, with the dac volume closer to maxed (80-90%), although technically I think you're supposed to max the source and use the amp to control volume.

And I see what you're getting at, so let me just say that with the dac volume very low *or even muted* the noise is still there. It now seems for sure to be coming from the amp.

It's a very weird almost static kind of sound, but a very "wide" static, like a soft crackling noise. And every few seconds there's a kind of more electronic sound. But since the dac is muted, I guess it can't be coming from the PC at all, right? It must be completely in the power line?

 

[powerslave]

Hmmm, try turning off that router and anything else that you think could cause interference, just leave on the pc, dac and amp. Also, is the amp plugged into the same outlet or strip? Do you get similar results if you use your laptop with the pc turned off? Just try different combo's to try to narrow down where your issue could be coming from.

 

[userlander]

Quote:

Originally Posted by powerslave /img/forum/go_quote.gif Hmmm, try turning off that router and anything else that you think could cause interference, just leave on the pc, dac and amp. Also, is the amp plugged into the same outlet or strip? Do you get similar results if you use your laptop with the pc turned off? Just try different combo's to try to narrow down where your issue could be coming from.

Lol - I have so much stuff plugged in there it's going to be a nightmare to figure out. There are two powerstrips and an APC battery backup with I think 6 outlets, all basically full with router, switches, cable modem, 2 monitors, 2 pcs, speaker amp, etc.

I've tried plugging the head amp into 1) the APC backup, 2) both powerstrips, and 3) the one empty wall socket left over from those 3 strips, all producing the noise.

Maybe tomorrow I'll run an extension cord from a totally different room and see if that works. I wonder if there's a grounding problem there instead of just all the stuff, because why would plugging directly into the other socket pick up that interference? Unless both sockets are affected by each other? (don't really know a lot about electrical stuff

)

thanks for the help - that gave me the idea to test the dac alone and then with the dac muted, which led me to at least figure out it's something to do with the amp power.