[kobune]

I'm buying a combo of Stax Omega II (Japanese version). It's said that it would work under 120V but may malfunction without a voltage transformer or even have reduced life. Is there any user in US or Canada to share some experience? I'll get a transformer ASAP if necessary.

Thanks in advance!

 

[Negatron]

Running on 120v is on shakey ground. Trusting that the power company is going to keep the voltage at 120v is dreaming. Do you really want it seeing 130 or more volts? Just a conversion transformer may not be the best solution for fidelity. You may try and find a transformer based power conditioner for 100 volts, it will see the 120 as overvoltage and pull it down. Industrial ferro-resonant power conditioners from Topaz, Thordarson, Sola, etc. sometimes have switchable voltage. And they are far cheaper used than audio conditioners, and work very well. Look for at least 300va for good current headroom.

 

[kobune]

Thanks for the advice, Negatron. Those power conditioners you listed are hard to get, right? Could you recommend some place? Otherwise I'll buy a transformer for temporary use first.

 

[wower]

I have been going back and forth between Japan and Canada for a decade now and have lugged more electronics with me than I care to admit (including some very nice Vestax DJ gear). While there are technical reasons to avoid it and some risk involved, voltage has never been a problem for me because in real world situations the voltages are very similar. (This extends to the overseas community, I have never heard it to be a problem.) I have looked into step up transformers but those are pricey and the audiophile ones even more so. 110V ---> 220V beware!!! (RIP poor little personal panny CDP.)

 

[Negatron]

Quote:

Originally Posted by kobune /img/forum/go_quote.gif Thanks for the advice, Negatron. Those power conditioners you listed are hard to get, right? Could you recommend some place? Otherwise I'll buy a transformer for temporary use first.

Ebay. Here is a start,
http://search.ebay.com/search/search...trypage=search
but models that are switchable to 100v output would be ideal. I beleve Thordarson Meissner makes several, as does Sola. I didn't say it would be easy. Just better than a step-down transformer as far a sound quality goes. Actually a conditioner that limits the output to 115 or 120 would be OK since the voltage would not be exceeded. I have measured 120v mains that were better than 132 volts at times and that is really pushing things for 100v gear.

Surplus conditioners are heavy, unattractive and sell relativly cheap in the under 10 amp range used for home audio. I've found them as cheap as $10 in thrift stores. The output is way better than what comes out of the wall from an audible perspective, provided they are not under rated for current.

 

[kobune]

These conditioners are really expensive. I may want to buy a transformer first to see if I can hear the difference.

 

[justin w.]

I don't think this is a very good idea. Your headphones will probably see the worst of it. The bias voltage is doubled off the transformer secondary, and you'll end up with nearly 700V instead of 580V.

 

[kobune]

Quote:

Originally Posted by justin w. /img/forum/go_quote.gif I don't think this is a very good idea. Your headphones will probably see the worst of it. The bias voltage is doubled off the transformer secondary, and you'll end up with nearly 700V instead of 580V.

It seems dangerous but I'm not good at the working mechanism of these electrostatic cans. Could you explain it a little bit more?

 

[akira]

I confirmed that some stax amplifier models have jumper pin system in it and are enabled to switch for any voltage (100, 120, 220, 240). It's not difficult when you can open housing. I estimate the most of their model are internally switchable since stax sell them worldwide.

 

[kobune]

Quote:

Originally Posted by akira /img/forum/go_quote.gif I confirmed that some stax amplifier models have jumper pin system in it and are enabled to switch for any voltage (100, 120, 220, 240). It's not difficult when you can open housing. I estimate the most of their model are internally switchable since stax sell them worldwide.

It would be nice if mine is in this case, but I see some of their amps are marked as "USA version" and ask for 120V instead of 100V (at elusivedisc) and the one I bought is said to be "Japanese version". I'm wondering if Stax makes different versions for the varied voltages or a single switchable model.

 

[akira]

Yes, none of stax amp are sold as "global model", but they have identical transformer actually. Mine was "Japanese version", but I changed pin position to 120V and sold it to a US Head-Fier. Changing jumper pin is not allowed for customer normally and to be done in their factory. However it's not so difficult.