[penguindude]

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!

 

[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?

 

[JLai]

Thats wierd...I have the same setup and I hear no noise at all unless the volume is way up.

 

[GotNoRice]

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.

 

[odmanca]

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.

 

[penguindude]

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?!

 

[penguindude]

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!

 

[odmanca]

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.

 

[Duc]

Yeah! So there!

Anyway, what the hell is a Ground Loop Isolator? Where does it go?

 

[BennyBoy]

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.

 

[BennyBoy]

Quote:

Originally Posted by Duc Yeah! So there! Anyway, what the hell is a Ground Loop Isolator? Where does it go?

You wont need one as the V3 was designed correctly.

 

[odmanca]

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.

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.

 

[penguindude]

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:

From Xitell:

Good Luck!