Usin Furrin Powered Stereo Stuff in the Good Ole US of A

[thebes]

I almost feel like some sort of backwoods buffoon, but for the life of me I can't figure out this 220volts 110 volts stuff.

One: I have a Ortofon MCA-76 Moving Coil Amplifier given to me by a friend but it's got the European plug and states on the back: "200-240v, 50/60hz". I've opened it up and there is no way too switch it to 110v like many devices and I have no schematic of the power supply.

I do however, have one of those European plug adapators. However, even it works, will it work properly without it being converted to 220v? I want to use this with my Denon Zu modified 103 to compare it with my preamplifiers high gain setting.

Two: I've got this very old military field dark room that is either Japanese or Chinese and has a light bulb in it, but I'm afraid of frying it cause it says 220v on the power cord (regular American style plug). Somebody told me that since it's only getting half the power if I plug it in here, it should be safe, but I really don't want to blow up this rarity.

You can see this gizmo here:

http://community.klipsch.com/forums/t/133325.aspx

Fortunately I'm sure the wise beards here will cogitate and inform as to how I should proceed.

[RockOn4Klipsch]

heyn thebes, I would run down to you office max type store and look for a power converter to give you a piece of mind.

[jtkinney]

What you really need is an electrician to install a 240v outlet near your turntable. Then get and adapter from US to furrin so you can use the European plug. Any inverter that will get you from 120 to 240 will have so much noise it might not be useable.

[Islander]

I almost feel like some sort of backwoods buffoon, but for the life of me I can't figure out this 220volts 110 volts stuff.

You can look at it this way: amperes (or amps) represent the actual flow of current (how much electricity), while volts represent the pressure driving that current, and ohms are the resistance in a DC circuit and impedance is the resistance in an AC circuit.

Obviously, giving power to an electric or electronic item with more or less pressure than it's designed for will cause a problem, unless it's one of those items like some pro audio gear and some electric shavers that will accept 90-250 volts at 50 or 60 Hz. The E-V Dx38 is like that. I think they're equipped with some sort of microprocessor that automatically detects what sort of power the component is plugged into and sets its power supply accordingly.

Incidentally, your home will have 220/240 volts coming in to the main panel, but only the stove and electric clothes dryer use it. For almost everything else, only part of the incoming flow (1 phase?) is used, giving you 110/120 volts at most of your outlets.

[thebes]

Thanks guys, getting a handle on this now, and not for the first time, not liking what I'm hearing.

So the chances are a converter is going to be too noisy, not a good thing when you are amplifying the output of a moving coil. Running a separate line is too costly for what's basically an experiment, and running this thing on half power is either gong to throw it out of phase, or put out only half the power.

Just wondering, but could I cut the cord and wire the two wires into a dryer plug and then plug that in skipping the ground.? Those dryer wires look kinda thick though, might fryolate the gizmo.

Dang furriners and their furrin ways. Wonder if any of them have the Merican version and would do a trade?

[LarryC]

Marty, were you interested in borrowing the PSAudio P-300 to see what it does on TT's, CDP's, or low-powered electronics?

Larry

[jtkinney]

Marty,

For an experiment, it could be wired into a dryer outled. Notice I didn't say that you should (gotta watch out fer them lawyers) , but that's how I would do it.

Just be careful out there.

[boom3]

Interesting nobody has mentioned the 50 to 60 Hz question. My impression is that for devices that don't depend on mains frequency (not a clock, or appliance timer and so on) it makes no difference once the voltage is matched. However, there might be an issue with power supply efficiency in electronics. You should ask over in the Vintage forum of Audio Asylum. There are some very experienced folks there who have restored Euro gear and used in the U.S.

Magellan's has a wide range of voltage and plug adapters for travelers, but I don't think any of them do a mains frequency conversion.

I really urge using an adapter and not tapping directly into the house 220 circuits..

[Mightyrajh]

I did 4 years in Germany in the 70/80's and I know the stuff. It is a preamp for moving coil cartridges which had lower outputs and (I think) much lower impedances than moving magnet cartridges. I also brought tons of equipment home (to Canada but the same power).

The preamp power supply power transformer may have 4 terminals on the input side which can simply be rewired from series (220) to parallel (110). I don't know how much electronics you know but any electrical tech could tell you straight up. If it only has two terninals then you want to look for a low power110/220 autotransformer. It will be cheap and give you the 220 without causing any grounding problems because it's not isolated.

The power supply will just change the 220V ACdown to around 12V DC anyway and the frequency has absolutely no effect on the operation.

[thebes]

Once again thank you my friends. Larry, the problem with trying out your stuff is I have a propensity to break things. Even if I didn't break it, I probably couldn't afford anything close to it, so why beat myself up over might-have-beens.

Ah, welcome o mighty Raj, I do believe you have given me the clue that I need. My feeling all along is that this was probably easily convertible, simply because manufacturers are practical and cheap at the same time. Since this product was marketed internationally, why have two different power supplies, when a simple conversion would suffice. Cameras out of batteries at the moment, so I'll put up a pic later, but it does appear that the transformer has four terminals, and I'm pretty sure how to move one bridge and add another and be rolling along at a safe 100v. What you say makes perfect sense and I'm in your debt until such a time as I rewire it and it blows up.

Should this occur, I would suggest a long fishing trip to the nether realms of the great Canadian wilderness. []

[Islander]

it does appear that the transformer has four terminals, and I'm pretty sure how to move one bridge and add another and be rolling along at a safe 100v. What you say makes perfect sense and I'm in your debt until such a time as I rewire it and it blows up.

I'd very strongly suggest that you put a meter on the output after you mod the transformer to make sure the output actually is what you think it should be, even if you have to go out and buy a multimeter. An inexpensive meter will cost less than almost anything you'll be trying to power with the transformer, plus you can use it to check your batteries, for the camera and whatever else, whenever you need to.

[thebes]

Well I gave it a whirl. Re-soldered it the way I thought it should be and no joy, then switched the bridges another way and wallah, she works!

Islander, before I hooked it up I did check the output and she's running at 14vdc so that's good enough for me. Fear not, I know just enough electronics to be very dangerous. But hey, that's what fire departments are for.

No judgment call on on the sound versus the built-in high gain settings on my preamp. Not sure if I will have to adjust my resistance loading but it's easy to switch between the head amp and the pre gain stage to do A/B's.