[clarinetman]

Well, my computer sucks, basically.
 
 
When I plug my DAC into the USB port on my laptop, the tube amp my DAC is plugged into picks up the processor noise, which is very disruptive to anything I happen to be listening to. Any ideas on how to fix this?

 

[Dynobot]

http://opticisolator.com/opticusb.html

 

[Uncle Erik]

It's not just the processor making noise. The switching power supply, fans and drives all throw out a lot of radio frequency interference (RFI) that gets fed into audio. The best solution is to use an external DAC, so the signal processing happens outside the computer case.

 

[clarinetman]

Quote:

http://opticisolator.com/opticusb.html

Thanks. That's awfully expensive though. Do you think if I bought some inexpensive snap-on ferrite beads, it would work the same way?


 
Quote:

It's not just the processor making noise. The switching power supply, fans and drives all throw out a lot of radio frequency interference (RFI) that gets fed into audio. The best solution is to use an external DAC, so the signal processing happens outside the computer case.

I am indeed using an external DAC, which is kind of confusing to me why it would be picking anything up.

 

[ROBSCIX]

You did try another port if you have it?
If this doesn't help you can try something like this isolator here: USB isolator
This unit allows you to remove the power from the system and add a clean external supply such as a battery or a adapter.
You can look around for other ones, but the best models allow external power input.
Should fix you right up.

 

[leeperry]

you need an ADuM4160 dongle, the cheapests I've seen on google were $40 or so

 

[clarinetman]

Quote:

You did try another port if you have it?

Sure did. Same stupid problem.
 
Oddly, I've observed that the static noise goes in and out. When it disappears and I touch the RCA input jacks on the cable, the static comes back. Don't think it's the cable though. I tried another one and it was the same thing.
 
Time for a new computer?

 

[clarinetman]

Quote:

You did try another port if you have it?
If this doesn't help you can try something like this isolator here: USB isolator
This unit allows you to remove the power from the system and add a clean external supply such as a battery or a adapter.
You can look around for other ones, but the best models allow external power input.
Should fix you right up.

Very cool! So it uses an AC adapter or....? How would I go about using a battery with it?
 
Almost 500 posts and still naive.

 

[leeperry]

the models w/ external PSU can have problems intializing(it's explained on the circuit@home site), I think the cheapest you can get that doesn't require an external PSU(it supports it, though) is on  http://www.olimex.com/dev/usb-iso.html

 

[ROBSCIX]

 
Quote:

Very cool! So it uses an AC adapter or....? How would I go about using a battery with it?
 
Almost 500 posts and still naive.

Yes, you can just get an external adapter, I use an external battery with a jack that connects right up.  Works great.
 
Is your laptop and DAC plugged into same power outlet? -or are you using a self powered type of USB unit.

 

[clarinetman]

Quote:

 

Yes, you can just get an external adapter, I use an external battery with a jack that connects right up.  Works great.
 
Is your laptop and DAC plugged into same power outlet? -or are you using a self powered type of USB unit.

Where could I get one of the batteries?
 
At the moment I'm using the crappy DAC on my XM5 portable which is self-contained. An Aune MK2 is on its way though which will need external power.
 

 

[ROBSCIX]

Quote:

Where could I get one of the batteries?
 
At the moment I'm using the crappy DAC on my XM5 portable which is self-contained. An Aune MK2 is on its way though which will need external power.
 

I just used a normal 9Volt battery with a connector that has a barrel that connects to the device.  I can give you a link if you are planning on going this way.