Moving From USA Overseas... Looking For Advice re: Electrical Service and Gear

hello all,

i'm moving from the USA to Vietnam (220V / 50 hz) and am looking for some advice on the best and safest way to hook up my system out there.  the area i'm moving to - district 2 in ho chi minh city - apparently has power outages monthly.  any advice on safely running my gear out there would be appreciated.

  • is it better to have my gear converted to 220V, or simply use a 220V - 120V step down transformer?
  • should i use an uninterruptible power supply (UPS / battery backup) or is a good surge protector sufficient?
  • is it possible to use a step down transformer in line with a UPS, ie, wall to UPS, UPS to transformer, transformer to gear?

as you can see, i have no idea what's the best and safest way to run USA spec equipment in Vietnam and would appreciate all inputs and recommendations.

I have lived overseas for the past 6 years and currently live in Southeast Asia. All my equipment is 120 Volts.  I use three 2500 Watt Diamond Series Voltage Transformers to step down from 230 to 120 volts. I have had no problems using these transformers and no issues with sound quality.  They are a very reasonably priced option that have worked well for me.  Recommend you check with your equipment manufacturers on the frequency change from 60 to 50 hertz to ensure there are no issues. I would expect not, but it's best to check. I do not use a UPS.  The equipment I power through these transformers includes an Antipodes DX server, Lampizator Golden Gate DAC, Yamamoto 300B amp and the powered subs in my Zu Definition speakers. Hope this helps.

I used a Seven Star AR2000 transformer automatic voltage regulator  when I moved from the US to France. Worked very well for me, no issues at all. See my previous post on this subject.

Thank you very much,...I am grateful to the OP and those who respond on this thread as I have a very similar question around a potential move to Argentina in about 1 year's time. Their power is 220-240 60Hz as well. 

Questions:  Is there a step-down transformer that in addition to converting from 220-240v, also changes cycles from 50 to 60Hz?

Also, it best prior to the move to purchase a sub-panel and proper breakers to take with you to have a local electrician install instead of just going straight from the step-down transformer to the your equipment.  My purpose for asking this is from multiple angles;  all transformers emit noise to a great or lesser extent in their immediate environment,...I would consider installing the transformer in a separate room and then running a large gauge feed to a sub-panel and then 10-gauge wire from the sub-panel to audio-grade receptacles in the wall (that I would also take with me during the move along with the proper in-wall boxes, etc....

What are everyone's thoughts on this? Am I wasting my time and energy if I go this route? I suspect I may not be as I could take things like my Environmental Potentials Ground filters, etc...with me for install in the sub-panel? I'm not an electrician so if I am blurring the details here and making mistakes, please let me know.  Thank you!!!!
Correction: Argentina is 220-240v and 50Hz so my question regarding a step-down transformer that would also convert (up) from 50Hz to 60Hz while it steps down the voltage from 220-240v to 115-120v is important.
I doubt it. You could check with the manufacturers of your equipment if it is fine to feed it with 50hz, or you could consider converting it to 220v/50hz.
I'd look into transformers, they have a series for refrigerators that would change 220-240v @ 50h into 120v @60h.

They also have power stabilizers @ 1000w & 2000w for brown outs.
not affiliated with them in any ways, except thinking of buying these two products for my own use.
good luck 
Yup, I looked them up. They do have it and you can buy directly from them. The company sounds good, I would give it a try for sure.
thanks for the inputs, all.

sounds like the best thing in my situation is going to be to step down the power from 220v to 110v and use my gear as configured (120v) rather than have it converted for native 220v operation.

the acupwr step down transformers look excellent... does anyone know if it would be safe to plug a USA spec (120v) Running Springs Audio Haley into the output of the 2000-Watt acupwr transformer? I came across an article that stated surge protection type devices should never be plugged into an autoformer type step down transformer, which the acupwr units appear to be.

one solution, in my case, is to step down the 220v power using the acupwr transformer, then connect that to my RSA Haley, then connect my devices into the Haley. this would, presumably, provide step down voltage via the acupwr and some protection from voltage fluctuations via the Haley.

any thoughts on if this is a safe path forward?


I feel the upside of using a Transformer is that if you move back to the States then you don't have to do internal voltage conversions all over again.

As to your question, I was planning to conncet the voltage stabilizer into the wall then the transformer into that and a Shunyata power distributor & surge protector into the transformer, and my components into the Shunyata. 

If you've read something against that it's best to call Haley and ask them for advice for using their unit.
I once talked to someone, Paul I think, from PS Audio about plugging in their regenerators into step down transformers. He said no problem but try to go with the transformer rated 1.5 times, that's if say, you have 1500 watt rated regenerator it should be 2250 watt transformer. However, this particular transformer company says it is not necessary, so I would assume that 2000 watt transformer would be more than enough for 1500 regenerator.
Don't know about Runnung Springs, maybe different.
Transformers and autoformers cannot convert frequency. I took a look at the Acupwr devices that were referred to, and I could not find any meaningful information at the site as to how the conversion they provide is accomplished. But it seems to me that there must be some parts and circuitry inside the devices in addition to the "autotransformer" (i.e., autoformer) that is indicated on their label. Which leads me to wonder how pure and undistorted a sine wave the device outputs, if it is in fact a sine wave at all, with that concern heightened by the fact that these devices are described as being intended for use with refrigerators, freezers, and other such appliances.

Before purchasing one of these things I would email the company and ask if they would recommend them for use with a high quality stereo system, and if they can provide some idea of how the frequency conversion is accomplished, and how much distortion is present on the AC output.

Good luck. Regards,
-- Al

I don't think any of these devices are intended for high quality stereo, that's not the point of making them. They have other transformers that they say don't change frequency just voltage. And I would expect enough distortion on the output. At least they look like quality things compared to cheap Chinese stuff.
+1 on the suggestion to contact the company.

i just pulled out the external transformer connected to my Mom's 27 qf GE fridge, it's by a company outa NY called Todd.
The unit states it's a 3 Prong transformer and converts 50h to 60h as well as 220-240 into 110-120v, 26 years on knock on wood no problems ever with the fridge.

should any of you contact Acupwr, please inform of your findings over here.

Al, why don't you contact them? You will know what they are saying.
Done!  I'll post back if and when I receive a response.

-- Al

+1 Thank you Al.
I’ll wait for your findings as well...

In the meantime I located the website for Todd transformers I mentioned before, the unit is called 3 tap (which I mistakenly wrote prong!) and this co. Has been around for forty years...

anywho, here is a bit from them:

"No transformer of any type can change frequency. Frequency is unimportant to the normal operation of most loads: most motor driven loads will simply run at a slightly different speed than they did at their rated frequency; simple heating equipment (broilers, coffee pots, etc.) will operate with no problem at all. However, motor loads whose proper operation depends upon frequency, such as clocks, turntables, timers, cassette players, etc. must be converted for voltage with a transformer and then also have their gears and/or pulleys changed for speed correction.

Some motor loads are heat sensitive to frequency changes. To avoid overheating sensitive motors, such as those that continuously stop and start, or run non-stop -- refrigerators, air conditioners, washing machines, shop equipment, etc., it is good practice to run 60 Hz motors at 10% less voltage when operated on 50Hz (e.g. 115 V 60 Hz equipment should operate at 100 - 105 V at 50 Hz). Conversely, to obtain full power from a 50 Hz motor operated on 60 Hz, it is necessary to supply it with 10% extra voltage (e.g. 220 V at 50 Hz should be operated at 250 - 260 V at 60 Hz)."...

lastly, I’ve seen people stating that they’re using external transformers with an amp just like mine (Levinson 532h) overseas with no issues... So I’m thinking that this may be more of an issue with TT, tape decks etc.?...
l'll wait for Al’s inputs...
thanks again

Thanks for the additional info, Lucidear. Following is the text of the inquiry I sent to Acupwr via their website:

Regarding your autotransformers that can convert from 50 to 60 Hz and vice versa, and are indicated as being intended for use with refrigerators, freezers, and other such appliances:

1)Would you recommend that these autotransformers can be used to power a high quality stereo system?

2)Can you provide me with some indication as to how these devices convert frequency? As an electrical engineer I know that a transformer or autoformer by itself cannot do so.

3)Can you provide me with some indication of how greatly the resulting output differs from a pure sine wave. For example is it a stepped approximation of a sine wave, or a sawtooth waveform, or some other approximation of a sine wave having large amounts of distortion?

Thank you.

Shortly afterward I received a phone call from a fellow who described himself as being non-technical but who said he had spoken to one of their technical people. He said that the tech person told him the output is essentially a pure sine wave, but that they would only recommend these devices for use with motor-driven appliances, and would not recommend them for use with a stereo system. I asked why that would be the case if the output is essentially a pure sine wave, and he couldn’t provide an answer but thought it had something to do with the connected motor providing a "kick" of some sort to the transformer. I repeated question 2 to him and again he couldn’t answer. He said he would try to have the tech person contact me to provide further detail, but that hasn’t happened yet.

I’ll post back if and when the tech person provides further info. Meanwhile I can only speculate that the "kick" he refers to, that would be provided by a connected motor, might have something to do with a phenomenon called "inductive kickback." That is the principle by which the induction coil in a car generates the very high voltage pulse that is applied to the spark plugs, and is the reason that a tube amp having an output transformer (which is inductively based) should not be operated without a load.

The bottom line at this point: I would not take the chance of using these devices with valuable audio equipment. Also, as was indicated earlier in the thread there are many audio components that are designed such that they can be used at both frequencies, as long as the voltage is proper. That should be indicated on their nameplate and/or in their manual.

Best regards,

-- Al

No way I'd move such a nice system all that way.  Too risky.  Better to find someone local to take care of your system until you are stateside again.  ;-)

thanks for you consideration and contributions to this thread.  Acupwr also makes step down transformers that only effect the voltage - frequency remains unchanged.

i have confirmed that all of my gear will be fine on 50hz, so am only condiderig these units.  Do you share the same concerns about the voltage only autotransformers?

is there another step down transformer that you would recommend?

thanks again,

Al, what do you think will happen if a turntable AC synchronous motor is run on 120 V and 50 hz instead of 60 hz ?
Also, is the the frequency really always stable 60 hz here in the US ? Voltage is definitely not.
Acupwr also makes step down transformers that only effect the voltage - frequency remains unchanged. I have confirmed that all of my gear will be fine on 50hz, so am only considering these units.
Great! I see no reason to be concerned about functionality issues or damage occurring with the step-down transformers that don’t purport to convert frequency. I don’t have any feel, though, for whether or not they would compromise sonics to any degree. Although I’d expect the degree of any such compromise, if present at all, to be system dependent.

FWIW I once had occasion to use a much less expensive 120V to 100V step-down transformer I purchased from, in a relatively non-critical application in a second system. It worked fine in that application, with no perceivable sonic side-effects.

Inna, while as you say USA voltages can vary significantly, and are considered to be in spec as long as they are between 114 and 126 volts (i.e., 120V +/- 5%), my impression is that the 60 Hz frequency is very tightly controlled. And things I’ve read in the past have indicated that typically it is monitored such that if synchronous clocks accumulate very small errors over a period of say a few hours (perhaps even well under a second of error, although I’m not sure of the exact amount), the frequency is adjusted very slightly to gradually bring them back to the correct time.

Regarding turntables having synchronous motors, if a particular model does not provide a means by which it can be adjusted for 50 Hz operation, then, yes, I’d expect it to run slow.

Best regards,
-- Al


Can you see any reason why powering a Running Springs Audio Haley line conditioner off the output of one of these autoformers would be a bad idea?  I've read several threads online stating that surge protection type devices should never be on the output of a step down autoformer - a transformer is ok, but not an autoformer.

Do you have a point of view on this?

I don't know the answer to that, Scott, or what the reason might be that it would be a bad idea.  And I'd imagine that the answer might depend on the design of the specific conditioner.  So all I can suggest is checking with Running Springs, as was suggested earlier.

Best regards,
-- Al
I see. PS Audio used to make P300, P600 and other regenerators that allowed you to change on the go both voltage and frequency output within quite a wide range. Newer ones don't let you change either. That was a good idea, why did they abandon it, I wonder?
Thanks, Al.  I've been trying to get that information from Running Springs but have yet to receive an answer.

Here's one of the articles I was referring to:
Thanks for providing the article, Scott.  Everything it says is well explained and makes sense.  However the kind of surge protector it addresses is the kind that utilizes sacrificial "varistors" ("MOVs" being the most common type of varistor), in designs that shunt surges to ground.

Most inexpensive surge protectors, that are commonly used for computers and other non-audiophile applications, are designed that way.  However I believe that the majority of relatively expensive protectors and conditioners that are marketed to audiophiles are not designed in that manner.  For example the BrickWall conditioner/surge protector I used to use, and the Audience conditioner/surge protector I currently use, do not use MOVs or other sacrificial devices and do not shunt surges to ground.

So hopefully RS will respond about the suitability of connecting their particular design to an autoformer.

Best regards,
-- Al

Thanks again,
forums like this and knowledgeable folks like you make life easier for the Rest of us...
Best Regards

If you have tointable with AC motor designed for 60hz, than you will also have to have either 50hz pulley or frequency converter.
Czarivey, thank you. Well, if I ever need it, I got lucky - there is 50hz pulley for the Nottingham motor available from the UK dealers.
I lived in Vietnam for several years in 2000's and brought my audio gear from the US with me. I bought a step-down transformer over there to use with my gear and never had any problems. I had the transformer customized a little bit and I think I paid around $100.00 for a 2 KVA. One thing you may want to be aware of is that most power outlets over there are ungrounded, so sometimes you get very light electrical shock when you touch certain part of your equipment. My suggestion is to negotiate with your landlord to have the outlets grounded. And remember to bring a few 3 to 2 prong adapters. You can find them there also. Let me know if you have other questions. 
I live abroad as well and greatly appreciate the topic and al's advice. I have used a Chinese step down converter to a monster surge protector to my amp for six years without a problem. The advice on grounding is good - I'm not grounded in my current house as it's very old and we do get mild to medium shocks which are a bit scary.

My next location is grounded but has power outages so I'm thinking of adding a ubs to the mix.

I wonder why battery power hasn't taken off for the audio world as it would solve a lot of problems. I used Vinnie rossis red wine battery amp and loved it. Was great for living abroad as it didn't require voltage conversion. 

Does anyone one know if a ubs which could power a decent sized amp? 

As far as I know, PS Audio did a lot of listening tests and modeling of power supplies. They concluded at the end that while they could make things sound different it wasn’t really better.

Their current units actually provide the equivalent of a high voltage source. They flatten the top and bottom of the sine wave, providing more current during those periods, giving power supply caps longer time at peak voltage, which would translate into better charged caps. This is a cute trick which raises the Vrms without raising the Vpk-pk.

I think they decided at the end of the day that all the additional flexibility wasn’t worth it. I would agree, but I would prefer the pure sine wave outputs.


Battery’s are no cure-all. They have a lot of effective source resistance, unless you use a car battery type device! :)

Dear god, please don’t use equipment designed to be grounded in an ungrounded situation! At the very least add GFCI protected outlets. They do not require a ground to work and will keep you from dying if an internal shock develops.

However, those grounds are life-safety grounds. They protect you from shocks and middle of the night fires which kill your family and pets. They should never be circumvented.

Companies like Pangea who allow this to happen with their products are just 1 accident away from being sued out of existence.