[amature101]

I have a portable amp which i let it charge from the desktop usb port all the time. However when i use it, i am lazy to disconnect it's charging cable and end up it's hissing a lot. Is there any product that can clean the power from usb port to allow cleaner energy which will make my amp reduce the hissing sound.

 

[ProtegeManiac]

OK, first off...just how far is the rear panel of the amplifier to make you too lazy to unplug the cable on the amp end? I mean the only reason to leave a USB cable totally plugged in is if you're also using it to send a digital audio signal to a DAC-HPamp unit, in which case, portables like Ibasso products have a switch to disable drawing power through there.
 
Now if you really need Wall-E to come and unplug it for you, but since we don't have Wall-E yet, you can just use the Schiit Wyrd. Make sure to read the product blurb and the thread here.
http://schiit.com/products/wyrd
http://www.head-fi.org/t/724519/schiit-decrapifier-released-usb-power-isolator

 

[Wiljen]

Other options would be an audioquest jitterbug, a hifimediy USB Isolator, or a USB Decrappifier.   All are made to clean up usb.   The other options are buy a good 5V power supply and just run the amp off that instead of using a PC port since you are not using the cable for data transfer.  Or and I kinda have to agree with Maniac the cheap and obvious solution of unplug it.

 

[ProtegeManiac]

Quote:

Originally Posted by Wiljen /img/forum/go_quote.gif

Or and I kinda have to agree with Maniac the cheap and obvious solution of unplug it.

 

Apart from it being free, in the absence of a charge switch, it keeps the battery from a constant charge-discharge cycle while in use, reducing wear and tear due to the cycles and heat build up (because I'm cheaper than I am lazy).

 

[Michgelsen]

  I have a portable amp which i let it charge from the desktop usb port all the time. However when i use it, i am lazy to disconnect it's charging cable and end up it's hissing a lot. Is there any product that can clean the power from usb port to allow cleaner energy which will make my amp reduce the hissing sound.

 
There probably are various products on the market that claim to do this, however you're most likely to pay way to much for something that may not work at all (because of point 3).
There are three options I can give you:
1. There this device from Aqvox, which separates usb power delivery and data transmission at the plug. Don't know how much this costs I'm afraid.
2. Charge with a higher quality external 5V charger. The folks over at Grace Design tested and measured a whole lot of external usb chargers and are selling what they found to be the best/quietest one for a very reasonable price here (bottom of page), to go with their m9xx. I don't know whether this could work for you, because you don't mention what amp your have. It could be that usb power and data go over the same cable, in which case an external charger cannot be used.
3. Alternatively, the hissing could be to a ground loop. I know this because I have acquired the above mentioned Grace m9xx a short while ago, and had noise problems via the usb connection, that sounded totally different from any grounding problem I had ever encountered. Still, proper grounding solved the issue completely, which surprised me. What proper grounding is all about, is making sure that every device in the audio chain is grounded at one point only. Remember that usb cables and RCA cables or other audio cables connecting various devices also connect their grounds together. So if your computer is grounded, make sure that none of the audio devices is grounded via its power plug, because that way your amp will be connected to ground at two points: via its audio cables via another device such as pc, and via its own power plug. In such a case, you can't disconnect the ground on the audio cables, meaning that you must lift the ground at the power plug.
 
If you give more information about your setup, we may be able to help you better.

 

[Wiljen]

Here is a thought, why not make your own USB cable and pull the power off the connector and run it to a 5V regulated wall wart.   You should be able to use about any Cell phone charger as the power supply and trace the two leads.  Strip the casing off a usb cable for about 6 inches at the end that plugs into the computer being careful not to cut or nick the wires internally.   cut the black and red leads at the connector and bend the wires away from the body of the cable.  You can use heat-shrink tubing to re-cover the remaining two wires (white(Data-) and green(Data+)).   To complete the power circuit, connect the red wire to the Positive lead from the charger and black to ground.    A bit of heat-shrink tape to make it look good and you're done.  This would completely remove the computers 5V supply and any problems it might introduce and should be little more than the cost of some heat shrink tubing.

 

[amature101]

  Here is a thought, why not make your own USB cable and pull the power off the connector and run it to a 5V regulated wall wart.   You should be able to use about any Cell phone charger as the power supply and trace the two leads.  Strip the casing off a usb cable for about 6 inches at the end that plugs into the computer being careful not to cut or nick the wires internally.   cut the black and red leads at the connector and bend the wires away from the body of the cable.  You can use heat-shrink tubing to re-cover the remaining two wires (white(Data-) and green(Data+)).   To complete the power circuit, connect the red wire to the Positive lead from the charger and black to ground.    A bit of heat-shrink tape to make it look good and you're done.  This would completely remove the computers 5V supply and any problems it might introduce and should be little more than the cost of some heat shrink tubing.

That's so not efficient, i could simply get a wall plug and connect my usb cable to the wall plug and draw power from the wall socket. The problem is that i dont have enough wall socket so i am charging my amplifier from my laptop usb port and using it at the same time. However for some reason, when my laptop usb port is charging my amplifier, my amplifier will detect a lot of hissing and transmit to my earphone.

 

[Wiljen]

  That's so not efficient, i could simply get a wall plug and connect my usb cable to the wall plug and draw power from the wall socket. The problem is that i dont have enough wall socket so i am charging my amplifier from my laptop usb port and using it at the same time. However for some reason, when my laptop usb port is charging my amplifier, my amplifier will detect a lot of hissing and transmit to my earphone.

 
efficient would be unplug it when in use as most everyone has stated.
 
Your options are:
1.) get a different power supply for the device
2.) unplug the device from the computer during use.
3.) buy a USB conditioner to remove any noise that is being introduced.
 
All three have been discussed already so it now is up to you to choose a course of action.

 

[Michgelsen]

Except that the noise may simply stop flowing when you properly ground your set-up, if applicable. Check that first, it could be a free solution.

 

[darkforce]

Maybe you just need a good quality USB Hub, like those seven ports models with 5V/4A external power adapter.

 

[ProtegeManiac]

  Maybe you just need a good quality USB Hub, like those seven ports models with 5V/4A external power adapter.

 
If the amp doesn't have a charging toggle switch there's still the continuous charge-discharge cycle on his battery while it's plugged in.