[MaMMa]

I just purchased the APC H10 and hoped it would get ride of the dial up modem like noise I hear, it didn't.

In the manual it says, "All outlets provide power surge protectionn, voltage regulation and noise filtering."

What am I doing wrong or is this a different type of noise?

I pluged it right into a wall outlet. I am listening to music on my laptop. The laptop is plugged into the H10. When I unplug the charger from the laptop and its running on battery, pure silence.


TIA,
MaMMa

 

[hardnrg]

That would indicate that the source of the noise is not coming from the mains, but either from the ac/dc power supply, or from the external power / charging circuit inside the laptop...

 

[Sovkiller]

The switiching power supplies are notorious for the noise, get a better PSU with more filtering...or use a linear one, but be very careful it has to be regulated...the noise is definitelly not form AC, return the APC it will do nothing...

 

[MaMMa]

This sucks, I got it off ebay.

 

[Cosmid]

I have the same problem. Can anyone suggest a specific budget product that should work? I will appreciate it. Thanks.

 

[catachresis]

Quote:

Originally Posted by MaMMa /img/forum/go_quote.gif This sucks, I got it off ebay.

One possibility might be to get another power supply specific to your laptop -- then you could test whether it was the supply causing the problem.

Another possibility could be to get an external dac and connect the music on your hard drive with digital usb to the analogue out on the dac -- eliminating the noise generated by the fans, power supply, etc.

 

[sum]

I am having a similar problem with my bedroom setup right now. The noise isn't generally audible, only with the headphone output of my mini-dac all the way up or with my Corda Aria level all the way up and no music playing. There is a bit of noise along with some cyclical noise added in. I've found that the cyclical component is being caused by the USB connection. If I move to an optical connection, it's gone. The other noise however is definitely mains contamination. I'm certain because when I move it into my living room and go through my Furman voltage regulator and isolation transformer, all noise is eliminated. Unfortunately there is no way I'm putting 80 lbs / $2500 worth of power conditioning hardware in my bedroom. C'est la vie.

 

[Cosmid]

Quote:

Originally Posted by catachresis /img/forum/go_quote.gif Another possibility could be to get an external dac and connect the music on your hard drive with digital usb to the analogue out on the dac -- eliminating the noise generated by the fans, power supply, etc.

To me it did not work. My iPod has Rockbox. I linked it to laptop and used USB as power source. I can hear the same noise from iPod if the laptop was connected to AC adaptor, and no noise from iPod if the laptop was run from battery. I thought about getting a standalone USB soundcard, but doubt if it could help. I am wondering if a power conditioner could help. At least I hope so.

 

[MaMMa]

Quote:

Originally Posted by catachresis /img/forum/go_quote.gif One possibility might be to get another power supply specific to your laptop -- then you could test whether it was the supply causing the problem. Another possibility could be to get an external dac and connect the music on your hard drive with digital usb to the analogue out on the dac -- eliminating the noise generated by the fans, power supply, etc.

When you say "Digital USB" thats just normal USB right?

 

[catachresis]

Quote:

Originally Posted by MaMMa /img/forum/go_quote.gif When you say "Digital USB" thats just normal USB right?

Right. But the thread above that mentions the use of a digital cable for direct digital out/digital in (at dacside) would be superior to the USB cable that combines data stream and power.

 

[MaMMa]

Quote:

Originally Posted by catachresis /img/forum/go_quote.gif Right. But the thread above that mentions the use of a digital cable for direct digital out/digital in (at dacside) would be superior to the USB cable that combines data stream and power.

So there is a digital USB cable and a normal USB cable for your "normal" computer use?

Sorry, but I have never heard of another type of USB or USB type cable.

 

[catachresis]

Quote:

Originally Posted by MaMMa /img/forum/go_quote.gif So there is a digital USB cable and a normal USB cable for your "normal" computer use? Sorry, but I have never heard of another type of USB or USB type cable.

"Digital Out" comes in two flavors: one kind is terminated with rca connectors, and looks like a single interconnect. It's specially formulated to transfer digital signals (as pulses of light). Another similar kind of digital-out cable is terminated with a little squarish adapter at both ends (and I forget what the specification term for this adapter is). Both these kinds of digital cables transfer the information -- and that's it. Because they don't also transfer power from the pc to the external device (usually a dac) they don't transmit much power-generated noise from the powered, noisy computer to the quiet external device.

USB cables transfer digital information (like photos from your digital camera) but they also transmit electrical power (so when you hook a flash card reader or a flash memory thumb drive to your USB port, the external devices get powered). So, the argument goes, distortion created by power goes from the pc to whatever is connected by usb (though how much distortion - I don't know). USB cables tend to be cheap, while decent digital cables are more expensive and built to a higher spec. Will this make a difference -- I cannot say for sure.

People here have lots of experience with particular external devices that use digital cables sometimes and USB cables others -- talk to them about their experiences and they'll be happy to help. I myself am stuck on two-channel separate audio systems -- I don't want to listen to music played out of my computer at all. Hard drives are where I store decent mps for cheap and cheerful mp3-players. That's my angle.

Good luck.

 

[imported_Matt_Carter]

Well this one's simple. Interference from your laptop charger....

All you need is a usb transit with tos out.

Here ya go,
http://www.m-audio.com/products/en_us/Transit-main.html
Haven't accually used this, but should do the trick.

Remeber use Toslink

 

[catachresis]

Quote:

Originally Posted by Matt_Carter /img/forum/go_quote.gif Well this one's simple. Interference from your laptops charger.... Everyone get a usb soundcard, transit, or processor, with tos out. Will solve the problem.

There you go. What he said.

 

[Nebby]

Quote:

Originally Posted by Matt_Carter /img/forum/go_quote.gif Well this one's simple. Interference from your laptop charger.... All you need is a usb transit with tos out. Here ya go, http://www.m-audio.com/products/en_us/Transit-main.html Haven't accually used this, but should do the trick. Remeber use Toslink

x2 on this. I had the same issue with noise when the laptop was plugged in, however the line out from my usb soundcard was silent even with the laptop plugged in; my guess is that it has decent power filtering....