I bought a 240V european amplifier (Ayon Spark Delta). As many of you know, there is a difference between US 240V and EU 240V. The US system has two 120V legs, out of phase with each other so that they measure 240V between legs. In europe they have a single hot leg that is 240V to ground (or neutral).
Some european amps will run just fine on the US system. However, my Ayon won't. It has a phase sensing circuit and expects to see a 0V leg and a 240V leg.
So I bought a transformer to step up the us 120 volt electricity (0V leg and 120V leg) to 240V. I expected to see the output legs to be 0V to ground and 240 to ground, just as in Europe. It even has European outlets on the front of it.
However, the output was 2 legs of 120V out of phase. I don't even know how it did this easily. It is a wound copper transformer (not SS).
My question is, how do I buy a transformer that will give me the EU standard (preferably something I can buy on Amazon to get this amp making music while I shop for a high quality transformer).
Jerry
Some european amps will run just fine on the US system. However, my Ayon won't. It has a phase sensing circuit and expects to see a 0V leg and a 240V leg.
So I bought a transformer to step up the us 120 volt electricity (0V leg and 120V leg) to 240V. I expected to see the output legs to be 0V to ground and 240 to ground, just as in Europe. It even has European outlets on the front of it.
However, the output was 2 legs of 120V out of phase. I don't even know how it did this easily. It is a wound copper transformer (not SS).
My question is, how do I buy a transformer that will give me the EU standard (preferably something I can buy on Amazon to get this amp making music while I shop for a high quality transformer).
Jerry
OK, is that in relation to ground? Because otherwise how would it know what 0V is? And do you think this is done because you might come in contact with the leg that is supposed to be 0V?
I assume it is in relation to ground. Your assertion is exactly why most amps work. But this one won't....
No I don't think it is for safety but it might be. It does have a motor to run a remote volume. It also has some relays that probably are expecting a polarity. The off switch won't turn it off when hooked up the the US standard 240.... there is a "polarity" light that comes on if the plug is backward. It is on no matter how the plug is oriented when using the US voltage.
It comes on, goes through warmup routine. Plays for about 60 seconds, sounds great, and goes back into standby and never comes out. The tubes glow nicely the whole time. Obviously the amp is ready to go but some control circuits are not letting it.
Jerry
No I don't think it is for safety but it might be. It does have a motor to run a remote volume. It also has some relays that probably are expecting a polarity. The off switch won't turn it off when hooked up the the US standard 240.... there is a "polarity" light that comes on if the plug is backward. It is on no matter how the plug is oriented when using the US voltage.
It comes on, goes through warmup routine. Plays for about 60 seconds, sounds great, and goes back into standby and never comes out. The tubes glow nicely the whole time. Obviously the amp is ready to go but some control circuits are not letting it.
Jerry
Strange feature. I sure don't know how to fix the problem, but let's hope someone here knows and has already had to deal with it.
The fact that a step up transformer doesn't work is also strange. Usually they are just autoformers with the neutral side going straight thru.
The fact that a step up transformer doesn't work is also strange. Usually they are just autoformers with the neutral side going straight thru.
Thanks Pano. I thought it would be simple. standard 120V US voltage is a 0 leg and a 120V let. So run it through a simple 2x step up transformer will give me what I need. For some reason, the transformer I I bought goes to a lot of trouble to convert it to the US standard 2x 120V out of phase. --Jerry
Mentioned transformer connected to your mains delivers 240V 60 Hz, while the amp needs 230V 50 Hz.
Just change it to a similar one with 120V primary.
An auto transformer should work.
A proper transformer with primary and secondary windings will also have some isolation from mains noise, so that is a better choice.
Look for the transformers sold in areas with a lagre Far Eastern population, they buy those to take home so they can use US appliances on 240 V, just use it in reverse.
An auto transformer should work.
A proper transformer with primary and secondary windings will also have some isolation from mains noise, so that is a better choice.
Look for the transformers sold in areas with a lagre Far Eastern population, they buy those to take home so they can use US appliances on 240 V, just use it in reverse.
Check the schematic, if it senses 50 Hz, then you will still have a problem.
Some designers make complex circuits for no real reason.
And try to look for a scrap amp, maybe you can make the primary side of the transformer work, remove the secondary windings, if it is a dual voltage set, lots of Japanese sets had those.
Use it as an auto transformer. Should work, if the VA ratings are suitable.
Some designers make complex circuits for no real reason.
And try to look for a scrap amp, maybe you can make the primary side of the transformer work, remove the secondary windings, if it is a dual voltage set, lots of Japanese sets had those.
Use it as an auto transformer. Should work, if the VA ratings are suitable.
Last edited:
Don't have a schematic. I'm pretty sure that frequency is not the problem. 60hz is easier on a transformer than 50hz. I"m going to get the right voltage to it (230 to 240, there's really no difference). Right now my home has 234Vac) and hopefully that will fix it. If not I'll pursue frequency next. Changing frequency is not easy and I never intended to do that. Pretty sure I won't have to.
I have 2 more transformers coming today and hopefully one of them puts out EU spec voltage. A friend checked his little transformer last night and it puts out 240V on the high leg so I know some of the transformers do. It is pretty crappy that there are a million transformers for sale on line and none of them tell you if they give you 240v to ground or 2 legs of 120V to ground. thanks.
I have 2 more transformers coming today and hopefully one of them puts out EU spec voltage. A friend checked his little transformer last night and it puts out 240V on the high leg so I know some of the transformers do. It is pretty crappy that there are a million transformers for sale on line and none of them tell you if they give you 240v to ground or 2 legs of 120V to ground. thanks.
I meant (if you did not understand):
0 - Common
120 - American Live
240 - European Live
The primary winding of an old dual voltage amp is used as the auto transformer, confirm VA before using.
0 - Common
120 - American Live
240 - European Live
The primary winding of an old dual voltage amp is used as the auto transformer, confirm VA before using.
NaresbBrd, Yes. I understand that. I'm trying to explain that this is my problem. I'm have now bought 3 transformers that are designed to allow use of European appliances in the US. The transformers take US 120 ( 0 common, 120 live) and convert it to 240, however instead of producing 0 common and 240 live, they produce 120V live and another 120V that is out of phase such that they are 240V between them. My amp detects this and doesn't like it. It needs common with 0V on it.
thanks, Jerry
thanks, Jerry
It's because those 120 to 240 transformers are using a balanced output configuration. To switch it to unbalanced with a new "neutral", simply chop the center tap connection from ground, and connect as below to create a live and neutral connection. Top is the current config, bottom is how to rewire.
Attachments
Last edited by a moderator:
I can't comment on above post, not expert in that.
Here some transformers were wound to get three phases from two, that can be done.
So what is suggested above is possible, from the drawing it is not clear whether the primary side is a coil or a motor.
Also, the phase shift is part of the winding design, how the transformer is made. The two coils may be wound on the core for a specific phase shift.
So I would check with a scope before feeding your amp, if it is really clean single phase or not...
Here some transformers were wound to get three phases from two, that can be done.
So what is suggested above is possible, from the drawing it is not clear whether the primary side is a coil or a motor.
Also, the phase shift is part of the winding design, how the transformer is made. The two coils may be wound on the core for a specific phase shift.
So I would check with a scope before feeding your amp, if it is really clean single phase or not...
Last edited:
@switch401. That looks easy. I'll see if any of the transformers I have are configured in a way that the wires are accessible to make that change.
How do you confirm the problem is ground related? Could it be the amp protection circuit detected some other problem after the amp warm-up?
EU style mains plugs do not have a fixed position for the neutral wire, you can plug them in either way. So it's impossible to know where the live wire will connect. This in contrast with UK style mains plugs, that do have fixed positions.
@switch401...spent a half hour with one of the transformers. Gets a lot more complicated with the 120 outlets, the fuses, etc. I found both wires coming out of the coils and going to the power leads of the 240. Couldn't find the lead coming out of the coils and going to ground. One does go to the neutral side of the 120V outlet. One does go to ground through the main power switch and a fuse but if I cut that one the transformer won't even power up. --Jerry
Can you take some pictures or maybe even sketch out how the transformer is currently wired? I'm having a hard time thinking through how things are currently hooked up.
Edit: If the transformer has a model number printed on it that may be helpful as well.
Edit: If the transformer has a model number printed on it that may be helpful as well.
Last edited: