HELP! Little Dot 2+ and HUGE hiss!
Oct 26, 2006 at 4:25 PM Thread Starter Post #1 of 13

penguindude

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Hey guys,

Just got my LD2+ today. Plugged it into my laptop + Audigy2 zs soundcard and HUGE hiss from electrostatic interference, and yes, even when i try to use my mouse the hiss goes crazy. Any suggestion for reducing the stupid emi? PS. The hiss reduces when i turn off my lappy's monitor so it must be the interference.

HELP!
 
Oct 26, 2006 at 6:07 PM Post #4 of 13

GotNoRice

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One time I had hiss on my Ld2+. I let it cool down and then switched the tubes, put the ones from the left side to the right side, and that fixed it.
 
Oct 26, 2006 at 6:54 PM Post #5 of 13

odmanca

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Quote:

Originally Posted by penguindude
Okay, so i found out that it's the power bar/supply of my laptop which is causing the hiss. IS there any way i can "condition" it?


It looks like you are using a PC/laptop-centric setup. In that case, why not try a UPS with a built-in battery to power the LD II+ before resorting to more elaborate and expensive schemes? I'm using an APC UPS I got from Office Depot for cheap (clearance price at $20) to power my LD II+ and there is no hissing, no humming, very, very quiet.
 
Oct 26, 2006 at 7:40 PM Post #6 of 13

penguindude

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Quote:

Originally Posted by odmanca
It looks like you are using a PC/laptop-centric setup. In that case, why not try a UPS with a built-in battery to power the LD II+ before resorting to more elaborate and expensive schemes? I'm using an APC UPS I got from Office Depot for cheap (clearance price at $20) to power my LD II+ and there is no hissing, no humming, very, very quiet.



Are you sure it's LD2+'s power supply that's causing the problem? What about the power supply of my laptop? Everytime i unplug my laptop AC/powersupply brick, the hiss is gone. Whose at fault?!
 
Oct 26, 2006 at 10:22 PM Post #7 of 13

penguindude

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Great news!!! The hiss is from the issue of ground loop! I went to Ratshack and got a Ground Loop Isolator and the damn hiss is gone forever!! Hahaha. Unfortunately, i now am not able to use my Monster Cable to interconnect my soundcard to the amp. Oh well, maybe i should just sell my Monster. Anyway, I will post my review of the LD2+ once burn in has complete!
 
Oct 27, 2006 at 12:17 AM Post #8 of 13

odmanca

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Quote:

Originally Posted by penguindude
Are you sure it's LD2+'s power supply that's causing the problem? What about the power supply of my laptop? Everytime i unplug my laptop AC/powersupply brick, the hiss is gone. Whose at fault?!


I see your problem is solved, great news. However, you misunderstood what I said in my post. I never said it was the LD II+'s power supply, my suspicion was confirmed by your solution, that it was the unclean AC power that's supplied to the LD II+. Whatever the problem was, an UPS will supply power from its battery instead of the unfiltered AC line, which usually improves/conditions the powerline to certain degree.
 
Oct 27, 2006 at 12:29 AM Post #9 of 13

Duc

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Yeah! So there!

Anyway, what the hell is a Ground Loop Isolator? Where does it go?
 
Oct 27, 2006 at 12:31 AM Post #10 of 13

BennyBoy

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Quote:

Originally Posted by odmanca
I see your problem is solved, great news. However, you misunderstood what I said in my post. I never said it was the LD II+'s power supply, my suspicion was confirmed by your solution, that it was the unclean AC power that's supplied to the LD II+. Whatever the problem was, an UPS will supply power from its battery instead of the unfiltered AC line, which usually improves/conditions the powerline to certain degree.


Unless your hooking up direct to the battery? the UPS only runs on the battery when it loses AC power.
rolleyes.gif
 
Oct 27, 2006 at 1:46 AM Post #12 of 13

odmanca

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Quote:

Originally Posted by BennyBoy
Unless your hooking up direct to the battery? the UPS only runs on the battery when it loses AC power.
rolleyes.gif



Yes, the model I've got has a switch to select power from the battery or AC line even with the AC line being active. Thanks for the clarification.
 
Oct 28, 2006 at 2:56 AM Post #13 of 13

penguindude

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Just a final conclusion to help those who might be experiencing the same problem in the future.

If you're experiencing a huge hum or hiss from your amp, it is probably due to ground loop issues. So you can either use a cheater plug and prevent the ground pin of your three-pin plug from being plugged in (this is dangerous AND illegal in North America) or you can get a Ground Loop Isolator. These are the few examples of Ground Loop Isolators:

From Ratshack:

pRS1C-2160121w345.jpg


From Xitell:

xitel_ground_loop_isolator.jpg



Good Luck!
 

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