[GuffMorgan]

Okay, so last night whilst listening to music I noticed static/fuzz/whatever you want to call it. I thought maybe it was just one recording, so I tried another, and another. Then I thought maybe I didn't rip the ogg's correctly (still new to it), so I tried my 320kbps mp3's, still there. Then I tried different headphones (switching from the Senn's to the Grado's) but it was still there. So then I thought that maybe it was the IC's, unfortunately I couldn't find another pair, so I just switched them over to my DVD player and played a cd through that, and the static was gone. So I'm thinking it's somewhere between my computer and the Firestone Audio Fubar II USB DAC.

Any one know of anything else I need to check on to help me diagnose the problem? Thanks.

 

[dan1son]

Is it a low hiss? popping noise? static on bass mainly? background noise?

There are so many possibilities here it's hard to say. The most obvious one might be the ICs are too close to your PC and are getting some interference from it. It could also be noise from the computer going into a cheap surge bar and back into the PSU for the DAC, same thing could be possible for your amp if it's plugged in.

 

[fjf]

May be a ground loop. The only way to avoid it is to connect all equipment to the same grounding point, trying to avoid ground connections between them. Hard to do, with the DAC and the computer connected with the usb cable. That's why a glass toslink cable is preferred between DAC and computer.

1-Unplug everything.
2-Disconnect the DAC ground power cable from the plug
3-Connect the dac and the computer with a thick copper cable (using screws on both metal boxes)
4-Make shure the computer is grounded!
5-Now plug and try.

This way the grounding of the DAC goes through the computer.

 

[GuffMorgan]

Quote:

Originally Posted by dan1son Is it a low hiss? popping noise? static on bass mainly? background noise? There are so many possibilities here it's hard to say. The most obvious one might be the ICs are too close to your PC and are getting some interference from it. It could also be noise from the computer going into a cheap surge bar and back into the PSU for the DAC, same thing could be possible for your amp if it's plugged in.

Eh, it's kind of like... hmm... well, you know when you have a bad recording and you have to turn it up loud and there's the background noise (noise that's kind of linked to vinyl a lot)? That's what it is, but it's on everything.

My main curiosity is why it's come out of nowhere, it hasn't been doing it for the entire time that I've had it all setup (about a month now), it only started last night.

Quote:

Originally Posted by fjf May be a ground loop. The only way to avoid it is to connect all equipment to the same grounding point, trying to avoid ground connections between them. Hard to do, with the DAC and the computer connected with the usb cable. That's why a glass toslink cable is preferred between DAC and computer. 1-Unplug everything. 2-Disconnect the DAC ground power cable from the plug 3-Connect the dac and the computer with a thick copper cable (using screws on both metal boxes) 4-Make shure the computer is grounded! 5-Now plug and try. This way the grounding of the DAC goes through the computer.

Well, I wanted to use the USB just for simplicity sake (which it has been, simple). But all of that's hard to try when I don't have a thick copper cable, I just have the standard ones. The computer is grounded, though.

 

[dan1son]

Hmm a background hiss?

I would check to see if you have it running through the windows audio junk. Maybe try Foobar 2000 with Kernel Streaming or ASIO see if that elminates it. Also if you have it going through a software EQ of any kind (winamp... etc) that could add some hiss. Maybe other software based effects.

You want the audio to go out of the USB port completely unaltered by any software. If your windows volume settings and stuff change the volume or add-reduce bass it's being modified.

 

[chych]

Sorry to bring up an old thread, but better than creating a new one.

I'm having the same issues outlined in this thread. I have figured these things out:

1) It is not a software problem, it is definitely some sort of ground-loop problem with the USB.
2) The Fubar DAC is not grounded to wall (no ground pin on wallwart), the chassis isn't even conductive (and the circuit ground isn't connected to it), it cannot be used as a general ground point. In my setup, computer and amplifier are grounded, and plugged into the same power strip.
3) When the DAC is plugged into my laptop, there are no hums and everything is awesome. My laptop does not have a ground pin on its AC adapter. However the moment I plug my firewire cable from my desktop to laptop (creating a ground loop), the DAC loses signal lock (replugging it in fixes it).
4) When connected to my desktop, all hell breaks loose. I get the same static background as mentioned by GuffMorgan. This static can be removed if I unplug & replug the usb cable, however the static returns after a few minutes (randomly). Occasionally it is even worse, the DAC loses its lock and all you hear is static (and often startles me when I have a loud song going).
5) When connected to my desktop, I get a 60hz hum from my amplifier only when the USB cable is connected (does not exist on my laptop). However if I jump the ground pin of the USB cable to the ground of the amplifier, this hum is removed. There still is locking error with the computer, however it may be less severe (it's hard to quantify). I can also remove this hum if I lift the amplifier from ground, but locking issues are still prominent.

What to do, what to do... I'm thinking I should connect all grounds of everything - computer chassis, DAC circuit ground, amplifier ground - together and hope for the best. However suggestions from more experienced people would be great.

 

[KevC]

Quote:

Originally Posted by chych Sorry to bring up an old thread, but better than creating a new one. I'm having the same issues outlined in this thread. I have figured these things out: 1) It is not a software problem, it is definitely some sort of ground-loop problem with the USB. 2) The Fubar DAC is not grounded to wall (no ground pin on wallwart), the chassis isn't even conductive (and the circuit ground isn't connected to it), it cannot be used as a general ground point. In my setup, computer and amplifier are grounded, and plugged into the same power strip. 3) When the DAC is plugged into my laptop, there are no hums and everything is awesome. My laptop does not have a ground pin on its AC adapter. However the moment I plug my firewire cable from my desktop to laptop (creating a ground loop), the DAC loses signal lock (replugging it in fixes it). 4) When connected to my desktop, all hell breaks loose. I get the same static background as mentioned by GuffMorgan. This static can be removed if I unplug & replug the usb cable, however the static returns after a few minutes (randomly). Occasionally it is even worse, the DAC loses its lock and all you hear is static (and often startles me when I have a loud song going). 5) When connected to my desktop, I get a 60hz hum from my amplifier only when the USB cable is connected (does not exist on my laptop). However if I jump the ground pin of the USB cable to the ground of the amplifier, this hum is removed. There still is locking error with the computer, however it may be less severe (it's hard to quantify). I can also remove this hum if I lift the amplifier from ground, but locking issues are still prominent. What to do, what to do... I'm thinking I should connect all grounds of everything - computer chassis, DAC circuit ground, amplifier ground - together and hope for the best. However suggestions from more experienced people would be great.

Good info. I'm kinda afraid of my Fubar II having this issue (in the mail). Anyone know how to get rid of this ground loop?

Does getting the Supplier change anything?