What's the "right way" to get Logitech Z680s running on 230v 50hz mains?

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xaphod

Member
2007-12-10 11:13 pm
What's the "right way" to get Logitech Z680s running on 230v 50hz mains?

Welp, i've just moved to Switzerland and taken my Logitech Z680 with me. I've tried plugging it into a step-down trasnformer but there's a noise coming from the sub that's really annoying. It sounds like the internal transformer of the sub itself is making the noise, as opposed to coming out of the sub's speaker but i can't tell. No noise is coming through the satellites. I highly doubt this is a ground-loop issue b/c there's no ground prong anywhere in this system :)

Okay so here are my options, please add to this list if possible...
1. Buy a bigger more powerful step-down. I'm eyeing this 1500W toroidal step-down: 1500W toroidal stepdown. This has virtually zero magnetic field and may produce "cleaner" AC than the crappy 500W E-I form step-down i'm using right now. For all I know my current 500W step-down is overloaded and is thus introducing sinusoidal distortion...

2. Buy some sort of "power conditioner" and plug it in behind the step-down. Belkin PF series products are the expensive examples. PS audio's "Humbuster" product has been dissembled elsewhere on this forum.. might get some help producing a diode bridge thinger to get rid of DC saturation problems... but i'm not sure that this is the issue

3. Mod the Z680 sub unit: replace the power-transformer inside with one that's capable of taking 230V 50hz mains. Is this possible? Is this ridiculous unless you know a ton about electronics? Is the 50hz thing a deadend: is the Z680 designed to eliminate 60hz harmonic distortion and therefore is ALWAYS going to have a hum if the mains is 50hz? No clue. You tell me :cannotbe:

Anyways. Losing lots of sleep over this. I don't know how to diagnose this problem and find out what it is . All help much appreciated!
 

xaphod

Member
2007-12-10 11:13 pm
Okay, cool. I have a multimeter and a limited understanding of electronics. Hopefully after I figure out how to get into the sub (there's a thread I saw on this somewhere I think on neoseeker?) will the transformer be marked? Or will i have to measure, and if so, do I have to do so while the tranny is under load?
 

xaphod

Member
2007-12-10 11:13 pm
Wahoo! After much smashing about, I managed to solve the problem: I opened it right up and determined that it was indeed the transformer inside the sub that was making the noise. (It was a toroid). I put foam underneath it to stop it vibrating agains tthe wood of the sub and that fixed the problem! (well you can still hear it a tiny bit but it's MUCH better)

WOOHOO!

btw, I posted pics:
here you can see the inside of the z680 with the sub speaker removed. The toroid power transformer is at the bottom right of the photo. No, you cannot get through from the back!

http://www.fuzzymunchkin.com/tdot/gallery2/main.php?g2_itemId=132367

here is a schematic copied from the front of the power transformer (toroid) in case you want to change it or something... (i was thinking of putting a new one in that did 230v mains but now i don't need to since hum is gone)

http://www.fuzzymunchkin.com/tdot/gallery2/main.php?g2_itemId=132364


I'm a happy guy now. 300 is playing...
 
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