Need to convert a music synthesizer from 110V to 230V.Voltage and fuse questions!

[projectwoofer]

Hello to everyone!

I'm new here and I have a rather elementary question. I live in Europe but just bought a rackmount synthesizer from the states...the Roland D-550.

So, I need to convert it to european voltage and have some questions: I've read the service manual and the power supply is universal and has slots for 100V, 117V, 220V and 240V...My country is on 230V, which one should I choose? 220V or 240V?

Moreover, the power supply uses 2 fuses:

1. The main fuse (F1) is a 315mA 250V and should be changed to a 160mA T 250V fuse..I do have a spare 400mA T 250V fuse but I suppose I should not use it?

2. The second fuse (F2) is a 1.25A N1 250V and should be changed to a 1.25A T 250V...do I really need to change this one too or to change the main fuse is enough?

Thanks a lot for any help!

 

[RadioRon]

I don't think you will notice any difference if you choose the 220V or the 240V selection. If you choose 220 and then plug into 230, you will be feeding voltage to its regulator inputs that is 4.5% higher than nominal, whereas if you choose 240V then you will be feeding voltage that is 4.2% low. These errors are small, and I suspect there is more margin than this in the power supply regulator design inside the synthesizer. If you feed voltage that is a bit high, then slightly more heat may be generated if the synthesizer uses linear regulators. If it uses switching regulators then there will be negligable impact. If you feed a voltage that is a bit low, you are eating into voltage headroom that the equipment designer has allocated, but not enough to cause any problems. Either way, your choice is probably safe. I would go with 220V.

The fuse is there in case of a serious fault. Since such a fault is unlikely, there is little danger in using a 400mA fuse temporarily until you can get the appropriate fuse. A few days may be alright, but don't forget. I would only change the mains fuse since the high current of that second one implies that this fuse is placed at a lower voltage point and is insensitive to changes to the transformer mains.

 

[projectwoofer]

Thank you very much! I really appreciate this!

 

[crutschow]

I agree with RadioRon's analysis except for his selection of voltage. I'm conservative so I would initially try the 240V setting to minimize stress on the electronics and only go to the 220V selection if the Synthesizer doesn't work properly.

 

[ben7]

The only thing the switch does is it switches the capacitors around (at least in a switch-modesupply) so they are under thier working voltage.
In fact, a switch mode supply will benifit from a higher input voltage.
The mosfet needs to be turned on less of the time, providing a cooler power supply.

 

[Nigel Goodwin]

Hello to everyone!

I'm new here and I have a rather elementary question. I live in Europe but just bought a rackmount synthesizer from the states...the Roland D-550.

You would do better to be more specific where you are, Europe isn't much help - the UK is 240V and the rest 220V, although both are nominally 230V.

 

[projectwoofer]

You would do better to be more specific where you are, Europe isn't much help - the UK is 240V and the rest 220V, although both are nominally 230V.

I live in Greece.

 

[projectwoofer]

This is from the service manual. Can anyone tell if it's a switcher or not?

 

[crutschow]

Looks like linear regulators at the output of the power transformer with taps on the transformer for the different voltages.

Thus I would start with the 240V tap first which will minimize stress and power dissipation in the regulators. Only go to a lower tap if you have problems with its operation.

 

[Nigel Goodwin]

This is from the service manual. Can anyone tell if it's a switcher or not?

No it's not, it's a conventional supply - presumably Greece is 220V?, but 240V should be fine. It will make very litte difference either way, as the outputs are regulated anyway.

 

[projectwoofer]

No it's not, it's a conventional supply - presumably Greece is 220V?, but 240V should be fine. It will make very litte difference either way, as the outputs are regulated anyway.

It was 220V years ago, now it's supposed to be 230V...so you're telling that I can choose either 220V or 240V with no probs?

 

[Nigel Goodwin]

It was 220V years ago, now it's supposed to be 230V...so you're telling that I can choose either 220V or 240V with no probs?

As far as I'm aware, there was never any change made - ONLY the specification was changed. So while the UK is still 240V, and the rest of Europe 220V, they both became nominally 230V - both 220 and 240 fall within the permitted limits for 230V.

So there were no changes to the supplies, ONLY to manufactured goods, where the manufacturer now has to make them based on 230V to be suitable for both 220 and 240.

As it's a regulated supply, selecting either tap should make no real difference.

 

[projectwoofer]

Ok, so the synthesizer arrived and I changed the voltage and the fuse!

Now I noticed that the cable that came with it says: 7A, 125V...does this mean that I cannot use it on 220V? It's the 2 prong 110V style but I have a small adapter to 220V 2-prong and tried to connect to mains for a while and was OK...

 

[Nigel Goodwin]

Ok, so the synthesizer arrived and I changed the voltage and the fuse!

Now I noticed that the cable that came with it says: 7A, 125V...does this mean that I cannot use it on 220V? It's the 2 prong 110V style but I have a small adapter to 220V 2-prong and tried to connect to mains for a while and was OK...

It only says that on the lead because that's where it's intended for, the lead will be thicker (because it's rated at double the current), and in my experience the insulation is often thicker than a 240V lead (again, because the cable itself is thicker).

If it bothers you, then change the lead.