usb power surge

soundcard just got very noisy

hey guys
i know this isnt realted directly to ntrack but was hoping someone could shed some light

i’m usisng the edirol ua-20 usb soundcard on my laptop, but everytime i plug it in i get a waring message “power surge on usb hub click here to reset” or stg to that effect, so i click reset and thats fine, cept for the fact that now my card is very noisy, whenever i move the mouse when the hard drive is searching etcetc

but heres the interesting thing, when i plug the laptop out of the wall and it runs on batteries, the soundcard is very very quiet and seems not to pick up any of that noise at all.

i dont remember it always being this way, i think it might be an issue with sp2, if anyone else has encountered this and has a solution or any suggestionis i would really appreciate it

thanks… james

There is a specified current limit (500mA?) that a USB device may draw from a port in place of using its own power supply.

Sometimes peripherals and a PC’s ports can be marginal on what they draw & supply and that gives problems - the device attempts to draw more current from the port than the port can supply. This may be what you are seeing.

I’m surprised though that unplugging the laptop’s PSU causes the problem to go away… I’d expect it to be the other way round.

Sometimes a powered hub between the PC and device can alleviate power issues.



Hi james kelly:
I have a suspission that you may have a power supply failure/issue with that laptop… The batteries bypass the power supply when operated on batteries… A computer guy with laptop expirence might be able to comfirm that… Does your other USB hardware operate O.K.? On either batteries or wall mains? Just my .02


hey guy
thanks for the comments
the current draw on the soundcard is only 170mA
i have it running through a hub that has its own power supply and it dosnt seem to make a difference weather the hub’s power suppply is connected or not! and yeah it does seem very strange that it only happens when the laptop is running off mains power!

anyway just for the heck of it i uninstalled sp2 and i no longer get the power surge on generic usb hub message but not much differnce with the noise.

the real issue here is with me! i’ve had this for 2 years now and i only started noticing the noise now!! but for the life of me i could not testify that it hasnt always been there! i think that’s more peculiar than the noise!!!

anyway my whole systme is due for its annual format in about 10 weeks so i’ll see what happens then!!

Hi james kelly:
Yes… It is nice to have a “Powered Hub” it removes the load and stress from the computer’s power supply to supply USB power to the USB devices… However, some USB devices don’t like these powered hubs… They like nice smooth/regulated DC voltage/current… Audio devices being one example… Have you tried this audio unit on another computer? That might isolate the Computer issue… ???


hey i solved it but i dont know how

basically i my speakers consist of a sony 5.1 surround sound dvd player ( i know i know… not what you want to be listening to to get a good mix but its all i have at the moment and its LOUD!!!)

SO i have my soundcard outputting to an auxillary in on the sony machine

i have the sony machine hooked up to a beko lcd screen by an s video cable to watch dvd’s.

i have the beko hooked up to the crt ouput of the laptop so that i can have dual monitor when i need em

now to keep this love triangle happy i’ve given each device its own plug socket and keep the transformers well away from eachother

so anyhow, my usb soundcard also has an earphones socket which i was using this evening and decided that hey! i no longer hear that annoying noise so perhaps the problem is in my sony amp/speakers. so i used a different pair of aux in’s on the sony from the soundcard, and i change the direction of the cables, and i played around with orientation of the devices and i plugged in and out my usb hard drive, and then because i had tried everthing else i plugged out the s video cable. THE S VIDEO CABLE now how the #### could that effect the audio seeing as the monitor it was connected to was at the time in no way connceted to my computer, the monitor was powered off and there should have been no signal coming or going along the svideo !! but none the less getting rid of the s video cable solved my problem!!

woo hoo.
i feel like i got my soundcard again for the first time, gotta love the silence! thanks again!!

Hi james kelly:
That is great to hear… I can hear the excitment in your post from here… Ain’t that great?