uk voltage question about a european amp

[cheis]

Hello,

I wonder if some of you electricity specialists can help me:

I have a bass amp that I used in Europe but I now live in the UK.
On various websites I see that the voltage in Europe and the UK is 230 V - 50 Hz

I'm not an electrician by any means but this indicates to me that the voltage is the same.

The makers of the amp (Ampeg) have answered me and told me to "have a tech rewire your amplifier for use with 240VAC." (Ampeg are in the USA so might not know.)

Interestingly, a UK guitar company called Matamp have told me not to worry and that their amp will work fine. ( I asked them the question for one of their amps also)

AT the back of the Ampeg bass amp it says : Line rating 220V - 50/60 HZ

So... safe to play or not?

Thanks!

 

[cheis]

here is the diagram

 

[SparkyChick]

The manufacturer appears to suggest different internal connections from the main PSU transformer, so I would advise against just plugging it in an hoping for the best.

There are a couple of changes in that diagram for 220v vs 240v operation.

Any chance you can take a picture of the inside of the amp showing the transformer and where the connections from it connect to a circuit board?

 

[Lucien Nunes]

And, if you have the actual schematic circuit diagram rather than just the wiring diag, that would be helpful. The colours of the transformer leads do not tell us much, but if the taps on the transformer are marked on the diagram with the lead colours, we can see what the differences are. Because the two versions show different coloured leads, there are either some unused taps with their leads sleeved, or they are different transformers.

 

[Lucien Nunes]

It's a Ampeg SVT 400 T. Valve.

Now you're trying to confuse me. It's transistor, not valve...

 

[cheis]

Maybe I'd be better off buying a European cable and just putting on an adapter for UK sockets in the wall. I can't believe that musicians have their amps rewired every time they tour in Europe. Or do they?

 

[cheis]

Now you're trying to confuse me. It's transistor, not valve...

SOrry! It's the kind without lamps in, so yes it's transistor. (I thought that valve was transistor)

 

[Lucien Nunes]

No, you don't need an adaptor, that has no effect on voltage, use a UK cable. The Ampeg manual I have shows only 120 and 240V versions. An amp genuinely built for 240V might not be capable of its declared audio output power when run on low 220V mains, so for mainland Europe, they may have supplied a transformer with an additional 220V tap, so that full output could be achieved at the lowest mains voltage likely to be encountered. When running on high 240V with the 220V tap connected, it might then be a little stressed - will probably work just fine but more likely to blow its output transistors at maximum sound levels. Most people probably wouldn't think to check or change it. Post pics of the transformer leads if you can.

 

[cheis]

Thanks , I had read somewhere that the US version of this amp is built for 120 Volt.

In mainland Europe, I've never used a transformer for this amp, just the black cable to plug it in to some electricity outlet. (picture above)

My reasoning is that if bot the UK and EUrope have the same voltage, why do I have to rewire anything at all? It seems easier to just buy a UK lead to plug in and play.

 

[SparkyChick]

There is a transformer inside the amplifier that drops the mains voltage supplied to it down to the level required by the internal amplifier components. This is what Lucien and I would like a picture of, and the leads that come out of it and connect to the printed circuit board inside.

 

[cheis]

Well, today I've just played with the amp using a European cable and a UK adapter and it works. Based on this, I think that I can use a UK cable of the sane type !

 

[Amateur]

Well, today I've just played with the amp using a European cable and a UK adapter and it works. Based on this, I think that I can use a UK cable of the sane type !

Yeah, I'd stay away from those Insane cables, they can be well dodgy!!!

 

[cheis]

Oh dear!