I moved from the US (120) ⇨ Norway (240) with two ML Requests speakers how to make them work?

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FrankHansen

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Hi,
I find myself in Norway with my favorite speakers.

Unfortunately, they have AC in and the switch from 120V ⇨ 240V makes it impossible to just plug them in.
Does anyone know how I could modify the speakers to work here in Norway?

Does the electronics convert from AC -> DC to power the panels and the built in speakers?
If so can I buy an adapter that goes from AC⇨ supplying the correct voltage and Amps?

If not, what can I do to make them work?
 

audioxcel

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It would be easiest to use step up transformers. Just don't buy cheap Chinese ones. Look on eBay or DOTmed for used hospital grade transformers. You could power both speakers (depending on model) with one 1000w transformer.
 
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JonFo

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Caution!

IIRC, the speakers also need to see the correct frequency (60Hz in this case), so you need a full-fledged AC generator that provides both 120v and 60Hz output.

Since all they are powering is the panel energizer, the draw is ridiculously low, so 15w at most.

These frequency converters are rare and or expensive. Ask around with other local audiophiles for conversion products available in your area that are FULL frequency converters, not just voltage.

For context, here is a thread about someone attempting to import US-spec speakers into Oz: https://www.martinloganowners.com/threads/prodigy-advice-needed-please.11447/post-127878
 

gvera

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Try to contact ML directly.
In my case, I live in Uruguay, no ML dealers here.
I wanted to buy a used pair of ML Montis in the US and import it.
I asked ML if I could do that and buy 220V circuit boards for them.
As an answer they sent me instructions on how to convert the Montises from 110V to 220V, a very easy task.
 

JonFo

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As an answer they sent me instructions on how to convert the Montises from 110V to 220V, a very easy task.
I believe that is only true for Gen2 powered models onwards, the Gen1 passives (like the OP's ReQuests) had the 'feature' (to protect local rep sales) that non-US models had different energizer power boards which were locked to the frequency (50Hz).
 

Paal

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Hi,
I find myself in Norway with my favorite speakers.

Unfortunately, they have AC in and the switch from 120V ⇨ 240V makes it impossible to just plug them in.
Does anyone know how I could modify the speakers to work here in Norway?

Does the electronics convert from AC -> DC to power the panels and the built in speakers?
If so can I buy an adapter that goes from AC⇨ supplying the correct voltage and Amps?

If not, what can I do to make them work?
Contact the Norwegian distributor Audiocompaniet/Olav Fluggsrud HiFi-Butikk high-end hifi Audio Audiocompaniet
Akustisk Bureau as Mosseveien 18B 0193 Oslo Tlf. 90137472
Olav can most likely help you witjh modificvation to use in Norway
 

audioxcel

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The AC mains is only used to charge the panels in older ML speakers without active crossovers and other electronics. It seems to me that the 60Hz vs 50Hz issue would only matter to the speaker's transformer load. Why can't the speaker's transformer be changed to be compatible?
 

gvera

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I believe that is only true for Gen2 powered models onwards, the Gen1 passives (like the OP's ReQuests) had the 'feature' (to protect local rep sales) that non-US models had different energizer power boards which were locked to the frequency (50Hz).
I'm sorry, I wasn't clear enough.
What ML sent me were the instructions to disable the 'frequency lock' you mention, still present in the Montis model, the board itself is multivoltage.
Don't know how it was implemented in previous models, cannot help with that.
 

JonFo

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Here is a quote from a dealer rep:
There are specific power supplies for 50Hz, that will not work with 60Hz, and it is the frequency of the line that will not turn on the PSU, not the voltage. The transformer on the AC board comes with two primary windings, and it is connected in parallel for 120V, and in series for 220V.
The problem is the board overall is designed for one frequency or the other. No easy conversions.

So the best option is to find the most reasonable source of 240v AC 50Hz -> 120v 60Hz AC for a 15w load.

Alternatively, the Norwegian importer could possibly sell you (if they have any) replacement boards (going to guess that will be at least €800 for two)
 
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Leporello

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Are these powered woofers or is the AC just for panel bias? Why should the voltage multiplier circuit care about line frequency?
 

audioxcel

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It would be easiest to use step up transformers. Just don't buy cheap Chinese ones. Look on eBay or DOTmed for used hospital grade transformers. You could power both speakers (depending on model) with one 1000w transformer.
I meant 240V -120V step down transformers.
 

audioxcel

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Hi,
I find myself in Norway with my favorite speakers.

Unfortunately, they have AC in and the switch from 120V ⇨ 240V makes it impossible to just plug them in.
Does anyone know how I could modify the speakers to work here in Norway?

Does the electronics convert from AC -> DC to power the panels and the built in speakers?
If so can I buy an adapter that goes from AC⇨ supplying the correct voltage and Amps?

If not, what can I do to make them work?
I have seen a lot of answers that state that just voltage conversion will not work and that frequency must also be converted.

Here is a relatively cost effective solution for you. Looks like the Thor model at 100W should be more than up to the task unless your speakers have powered woofers.

 
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audioxcel

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I have seen a lot of answers that state that just voltage conversion will not work and that frequency must also be converted.

Here is a relatively cost effective solution for you. Looks like the Thor model at 100W should be more than up to the task unless your speakers have powered woofers.


If you think this will work for you, You can contact KCC to ask if they can provide a unit with a hospital grade US duplex, outlet. Otherwise, you would have to use a plug-in cube to expand the outlet so you can plug both speakers in. In any case, the specs indicate that this solution should result in clean power that is as good or better than what you might get with a highend conditioner.
 
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planckscale

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I posted this below on another thread, but applies here equally:

Here in Tanzania, it is 240V 50Hz. I have been living with my USA Martin Logan SL3 since 2005, which now have new panels (bought in 2021). Initially, I used a voltage stepdown and the speakers will only turn on for 10 seconds. That is, 240v to 120v without changing the frequency from local 50Hz to 60Hz will only make them sing for about 10 seconds before they shut-off.

Solution: Power Plant P300-Power Conditioner.
This is a well-built power conditioner/stabilizer from PS Audio. Got it used on eBay for about 500 USD (They are a little less now). Actually, bought two!

Eventually, I went and bought the 240v/50Hz power modules from Martin Logan, which at the time cost me 100 USD each.

So you have two choices here; either to use a Voltage/Frequency converter or buy the power module from ML (if they have them for your model).

Asante!
 

Tosh

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USA-sold MLs need to see the 60Hz. I would try a 12VDC to 120VAC/60Hz car-type inverter plugged into a 240VAC to 12VDC (autosound-type bench supply). Inverter could be of a small size so no need for fans.
 

tridentsx

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I had the same problem, when moving from US to Sweden, I bought a pair of new boards from ML at the time they cost me $135, I eventually moved back to US and switched back to the original boards.

Right now I am on a business trip and will not be back until 10th August, the old 220 boards used to be in my garage, not sure if I have chucked them in the trash or, not if I still have them you can get them for the cost of shipping.
 

Robert D

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Im curious aboutvaudio equipment voltages in general. When we took a vacation in Italy, we just brought some converter plugs with us for doing things like charge our phones. Would those work with amplifiers and other equipment like media players and receivers? I'm going to guess no.
 

audioxcel

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Im curious aboutvaudio equipment voltages in general. When we took a vacation in Italy, we just brought some converter plugs with us for doing things like charge our phones. Would those work with amplifiers and other equipment like media players and receivers? I'm going to guess no.
No.
 

Reverb

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Hi,
I find myself in Norway with my favorite speakers.

Unfortunately, they have AC in and the switch from 120V ⇨ 240V makes it impossible to just plug them in.
Does anyone know how I could modify the speakers to work here in Norway?

Does the electronics convert from AC -> DC to power the panels and the built in speakers?
If so can I buy an adapter that goes from AC⇨ supplying the correct voltage and Amps?

If not, what can I do to make them work?
Hi Frank, just curious, how did it go?
 
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