120V 60Hz

Discussion in 'Amps and Cabs [BG]' started by Naumann, Mar 21, 2005.

  1. Naumann


    May 12, 2004
    Hi folks,

    I live in Europe and I'm going to buy combo (Eden cxc110) in USA. It is US version, so it is powered 120V 60Hz. In Europe we have 230V 50Hz. My question is how to solve this problem. It's easy to reduce 230V to 120V, but still frequency is 50Hz, not 60. Any ideas? Maybe someone from european countries know what should I do?

    Best regards,
  2. You can get step down transformers, im not sure about for the EU, but have seen plenty UK ones (closer to EU than the US anyways!)
  3. Trevorus


    Oct 18, 2002
    Urbana, IL
    You may e-mail eden about it. You may have to take it to a shop to have it changed over. My GK head only needs a couple of wires moved in order to be able to work in europe. The problem with conversion transformers is that they cannot handle a lof ot wattage, and if you can find one up to the task, voltage sag may damage your amp.
  4. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Power transformers are in general a little bit happier and more efficient operating at 60 Hz than 50. I don't think you have anything to worry about once you get the voltage converted.
  5. notanaggie

    notanaggie Guest

    Sep 30, 2003
    If it truly is 120V 60Hz only, it will be very unhappy with 50 Hz. The problem is that the "magnetizing inductance" (a property of transformers) is too low for the 50Hz, and it will draw too much current and overheat much faster. It may possibly even overheat with no load.

    If it is OK with the 50 hz, it should also have taps or windings which allow it to work at 230 or 240 V. Naturally then there is no problem once it is re-wired.

    There is one way you can use a true 120V 60Hz only transformer at 50 Hz. That is to operate it at 100V instead of 120V. Power will be reduced, but the no-load current will be normal again. It has to do with the physics of transformers.

    Naturally, some cheaper units may have trouble operating correctly at the lower voltage, so that is a potential issue.

    Eden I don't know about, but I would expect most Eden stuff to be re-wirable. Check on their website and see. Or ask them.
  6. popinfresh


    Dec 23, 2004
    Melbourne, Aus
    I personally wouldn't do it. Three main reasons:

    1. With all shipping/income tax/other taxes, alot of the time, it doesn't come out too much cheaper.
    2. Warranty, if anything fails, your Eden UK distributor doesn't want to have anything to do with you. All repairs are at your expense, which sometimes means ending up paying more in repairs (Plus the initial money) then what it would of cost to buy in the UK.
    3. Tone. My bass teacher (two of them) have repaired many amps in their time. They got/get alot of people who would come in to look at an expensive amp, play around with it, then go 'oh this sounds really nice, but you know what, i'l go import one from America and save a few dollars!'. The next thing you know, the same person(s) come into the store with their recently imported amp which have either had the internal voltage tap changed or are running off a transformer. they come in complaining of the amp sounding pretty bad, nothing technical, just not sounding like the nice amp they'd tried. They a/b against the one in the store and notice a significant difference in tone. The answer, most (not all though) amps that are made to run on 110 volts, are meant to run on 110, not anything else. They've even asked my teachers if they could swap with the ones in the store, of course getting a no from the shop. They're now left with an average sounding amp and no-one to sell it to (Who wants to buy a used one that's running on a transformer when they can buy a used one for the pretty much the same price that's running on what it's meant to?)

    Anyway, my $0.02. If you really must import and not look for used gear, contact Eden i suppose and also make sure you know all costs of importing (I got hit with a few hidden ones when importing my bass).
    Also, just be aware of the consequances of getting rid of the thing if you want to sell and the warranty/tone issues.

    Good luck!
  7. Bob Lee (QSC)

    Bob Lee (QSC) In case you missed it, I work for QSC Audio! Gold Supporting Member Commercial User

    Jul 3, 2001
    Costa Mesa, Calif.
    Technical Communications Developer, QSC Audio
    Sorry, I thought you were going from 50 Hz to 60, not the other way around.
  8. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    The importing to europe deal seems to be a new phenomenon.

    There are some potential difficulties, but admittedly, often it is a relatively minor matter as far as function is concerned. You simply have to check ahead of time for the unit you are considering, if you feel you MUST go around the manufacturer's legitimate agents....which we certainly would prefer you did NOT do in the case of our units.
    Naturally, as a manufacturer employee, I have some stake in our overseas agents getting your business, so you can take my comments as you will.

    Some points:

    1) The US version, even if nominally convertible, may or may not carry the CE mark that is required for importation into the EU. This may not be an immediate legal issue with customs. However it may be an issue with legal, safety and liability considerations later, if a defect causes a problem and the unit is found to be a "gray market" import.

    2) There may be patent issues, with the unit itself, or with parts used in the unit. Sometimes the EU versions must use a different part than the US version. Patent infringement problems, while unlikely to come up, can result in siezure of the product.

    3) The manufacturer agent is unlikely to be happy with you for going around them. Good luck with warranty repairs on a unit that they didn't sell. The US manufacturer has delegated warranty responsibility to the importer, and usually can't help you unless you ship it back to them. And, with Ampeg at least, the serial number is a dead giveaway that the unit was not made for export, so no chance of hiding that.

    4) Most serious manufacturers do have export versions. And many of the nominally US-only versions are actually easily convertible for other voltages with simple internal re-connections, and possibly a fuse change.

    5) Contrary to one post above, there is no particular reason for the "sound" of a suitably converted "gray market" amplifier to be different from one "legitimately" imported.
    In the case of the easily converted units, it hardly matters "who" does the conversion, as long as it is done correctly. The factory does the same thing, and the difference, if any, is usually limited to the safety agency certification stickers and the warranty cards provided with the unit. Possibly there is different packaging for sea shipment.

    In the case of a unit that must be operated with an external voltage conversion transformer, naturally there may be some sound issues due to the unit simply not being intended for the 50Hz power. And unless the unit were a highly desirable classic, I would think a converter would make it nearly unsaleable later, as noted.

    So, your choice.
  9. icks


    Jul 12, 2001
    Charleroi, Belgium
    i bought my vintage ampeg on ebay US. So it's also a 120v at 50hrz.

    I live in Belgium where the power is 220V at 60 hrz. I bought a transformater, it's a heavy (8kg) black metal box that can handle up to 1200VAC. It costs around 80€ ...

    Everything works nicely !
  10. Joe P

    Joe P

    Jul 15, 2004
    Milwaukee, WI
    Yup. It probably isn't a problem, but going the other way (50Hz to 60Hz) certainly wouldn't be.

    Assuming that it's a regular rectifier supply, and not a switching supply - It's actually easy to test for on the bench. You can open-up the transformer's secondary-side (the 'amp' side) - so that it'll run no-load - then variac it up while looking at the current waveform on a 'scope. The waveform starts pretty smooth and sinusoidal, then as you increase voltage the top starts to flatten a little with sort of a sloped-looking flat. When the core starts saturating, the flat develops a little hook on it - a litte peak; go past that, and it gets real obvious - a big'ol spike. This test can't hurt anything with the amp disconnected from the transformer. If you get up to the 120V at 50Hz, and the spike hasn't even started much yet to speak of, then it's fine; even if there is a little spike it's most-likely fine - but no-spike, no problem!

    Oh! A more 'numbers'-way to confirm it would be to measure the no-load current (it has to be a TRMS meter, but most of'em are) at 100V, 50Hz - like Notanaggie says (but don't run the amp that way!) - this'll tell you what the energizing current would be at the rated 60Hz frequency. Then you can compare the difference in current measurements between like backing it off to 80V, and increasing it to 120V - if the jump isn't a huge difference (like say - the current goes down by .2A pulled to 80V, and only increases by .3A when you push to 120V), then it should be fine also.

    If these flux tests pass, then you can just keep the 50Hz, but step it down to the rated 120V - no problem.

  11. popinfresh


    Dec 23, 2004
    Melbourne, Aus
    Sooo, seens theres a few tech guys around in this thread.. If i was to get a Mesa/Boogie Basiss 2000 of Ebay in the US and get it shipped to me in Aus (240volt, 50Hz). Could i easily just get the wiring changed inside and run it over here fine.. The 50/60Hz part doesn't matter?

    Jerrold: Yeah, I wouldn't of thought it'd change the tone either. I'm just saying what my teacher told me (He's a trust worthy guy who has done many repairs/seen alot in his time.
  12. To be fair, it all grinds down to the fact, that getting something from america is rediculously cheaper,

    Ampeg SVT II Pro:

    Music123.com - $1,499 (and thats the 220volt one too!)
    Worldwide Shipping - $227.64
    Import Tax = 17.5% of total = $302.17

    Total = $2,028.81

    Electrohill.com (fairly priced uk site)
    Ampeg SVT II Pro = £1,735
    Shippind - £14.55

    Total = £1,749.55 ( = ~ $3,291.42 [ www.xe.com] )

    $3,291.42 - $2028.81 = $1262.61 = £670ish of a difference :scowl:
  13. popinfresh


    Dec 23, 2004
    Melbourne, Aus
    See, they have a 220 volt version of the SVT2 Pro listed on there.. Why do they only have that head with a 220v option? Why not others? :(
  14. So they can segrigate the pricing to different contries depending on the profit margins they get from each one :scowl:
  15. popinfresh


    Dec 23, 2004
    Melbourne, Aus
    I just wanna make sure.. So your saying (techs) that if i get the voltage changed. The 10hz difference doesn't matter? (from 60 to 50)
  16. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    A unit which is internally rewirable to 230/240 should also be able to deal with the 50 Hz, yes. Certainly ours are, and I don't know of any that are not from others.

    If you have a unit of ours or anyone else's, which does NOT have a 230/240 capability, so that it is made specifically 60 Hz /120V......... well its a fair bet it won't deal well with the 50 Hz either. So in that case, the 10Hz difference WILL matter.
  17. bassbinge


    Sep 17, 2004
    new zealand
    eden amps are switchable for 115/230 volts all it takes is changing a couple of wires over internally.there usually is a diagram on the inside of the cover showing all the different voltage changing options.if no diagram you can get it from Eden.
  18. I could understand being worried about the 60 versus 50 Hz problem....if the transformer was right on the brink of its design parameters. Decades ago, transformer design was still in its infancy (from a theoretical point of view). But today, the theory is pretty well understood and the design principles have been worked out very well. The problems that were encountered with lower frequency mains have been solved years ago. So IMHO most transformers today (in the range of VA that we are discussing) are perfectly capable of handling 50 Hz AC supplies, provided the transformer gets a reasonable amount of air space and its rated VA capacity is not exceeded.

    As far as the rest of the amp, the bridge rectifier essentially won't care, and the filter caps won't care either.

    Most people don't realize that a solid state amp converts its AC supply to DC supply voltages (with rectification and filter capacitors) so a decently designed amp is virtually unaffected by minor differences in the line voltage (for example, whether its 115 volts or 120 volts).

    Tube amps are affected a little more. The heater (filament) voltages should stay pretty close to nominal--that's why you DON'T put a Variac on the AC supply!! The other voltages (B+, etc) are also DC, again through a transformer, rectifcation, and filtering with capacitors...vary these voltages some, and tone will be affected. But 5 volts or so on the AC line probably won't matter much.
  19. If it has the option to switch between 220 and 110, you should be fine. AC is only used because its convenient for transmitting power to the house. Transformers convert AC voltage/amps nearly losslessly. 110V/2amps =220V/1amp. All they need is AC input, requires a moving electromagnetic field to work. If you get too low in freq, you approach DC, and you'll have problems. 50 vs 60 hz isn't much of a difference. There may be a slight theoretical difference in efficiency, but its negligible.

    Where you have problems with 50hz is in some types of electric motors. And maybe TV sets, the 30 frames/sec seems an odd coincidence, maybe they use the power line to sync against, but that's a stretch of my imagination. What's the sync rate of PAL? If that's 50Hz, maybe not such a crazy theory after all.

    Solid state amplification circuitry operates on DC voltages. They convert the AC to DC. A 50 HZ input freq has the potential to let the voltage sag a bit since each of the capacitors are getting refreshed 100x/sec instead of 120, and so have to "hold their charge" a little longer. Not significant. If the power supply is regulated well, there's no trace of 60Hz left, then 50Hz ought to be fine. If its not well designed, you may get a slight ripple @100 hz in the DC voltages. And a little more buzz in your signal to noise.

    Why would switching power supplies freak out over different frequency? How do they know what freq the power supply "is" at or "should" be at?


    I'm not a tube guy, so I can't comment on filament heating issues. The above applies to solid state circuitry. But the function of the current is to heat the filament and loosen up electrons. How does it know what the frequency is? It doesn't.

    The only difference is you'll get a loud 50hz buzz out of your amp if you unplug your bass with your amp on instead of the normal 60Hz in the States. Unless you have perfect pitch, you'll never notice.
  20. Just a random note, this always bugged me, why are there 220v options? the uk mains voltage is 240 :p