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What to do: 220v vs 240v

IVELIN

pfm Member
Hello,

Last year I bought an amp from mainland Europe and saw that the AC voltage on the back is labelled 220V, also on the transformer inside there is a little sticker saying 220V. I have been using the amp and I suppose it runs a bit hotter than the expected and the transformer might be getting saturated. At home I get around 245V. However I got myself thinking if there is anything that I need to do to address this discrepancy? I am kind of familiar with the voltage differences between the UK and Europe and that even though we are supposed to be matched at 230V in reality that's not the case.

The amp's transformer is ILP and it has extra wires safely tucked away. Is it possible that one of them is for 240V input?
IMG-20200719-152557-2.jpg


Thanks!
Ivelin
 
Hello,
The amp's transformer is ILP and it has extra wires safely tucked away. Is it possible that one of them is for 240V input?

Thanks!
Ivelin

Don't know if this helps but a couple of years back I rebuilt an ILP modular amp that I originally put together when I lived in Holland (looked nothing like yours except the trafo to PCB connections).

I was a bit concerned that the toroidal transformer might be specified to 220v and after a bit of searching discovered that ILP were still active and sold via eBay so contacted them via their business details listed there:
https://www.ebay.co.uk/usr/ilpdirectltd

Ian Potts
ilp direct ltd
[email protected]

I cited the model number printed on the trafo (in my case 42027) and Ian replied a while after confirming this model was suitable for 240v operation.

You could try the same path ....
 
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Those extra wire are primary side, so there probably are options.
I would expect that two of them are joined, for 220V vs 110V operation.
To see what is going on, you need to (cautiously!) measure the voltage on each wire relative to neutral
 
Thank you very much for the replies. First I will try and get in touch with ilpdirect - hopefully Ian can help with information about this transformer.

James, regarding being a DIY-confident, I have never done anything like this so based on my experience I would say I am not that confident but happy to try if there is a step by step howto with parts list or something like that. Are these available ready built anywhere?

Here is a side view of the wires:
IMG-20200418-142356.jpg

Is there a colour convention for transformer wires?

If I wanted to change the transformer what would be the way forward?
 
James, regarding being a DIY-confident, I have never done anything like this so based on my experience I would say I am not that confident but happy to try if there is a step by step how to with parts list or something like that. Are these available ready built anywhere?
The ESP link I posted above explains how bucking transformers work, and how they are wired up. I'm an electrical numpty, but I took my time to understand the wiring diagram, and what sized transformer I needed. Then it was a simple matter of lashing it up in a case, and measuring the output voltage to make sure it was stepped down rather than up before connecting it to my amp.

But if you don't feel confident doing it yourself, then I'm sure one of the resident DIY fishies can help you out. I would offer, but I'm likely half a world away from you.
 
The ESP link I posted above explains how bucking transformers work, and how they are wired up. I'm an electrical numpty, but I took my time to understand the wiring diagram, and what sized transformer I needed. Then it was a simple matter of lashing it up in a case, and measuring the output voltage to make sure it was stepped down rather than up before connecting it to my amp.

But if you don't feel confident doing it yourself, then I'm sure one of the resident DIY fishies can help you out. I would offer, but I'm likely half a world away from you.

I read the sound-au and I think I understood the concept of the different combinations. I did not understand what nomenclature is used if I want to buck 20-30V. I can read diagrams but I am missing the more detailed knowledge. The schematics don't look complicated e.g. Figure 4 - Proper way to wire a bucking transformer, and I think I could possibly build one. I read somewhere that it is difficult to get the windings out of phase.
buck-transformer.png

The above looks simple and I am thinking maybe the amplifier is wired like that and hence the sticker 220V (does not explain the external label though)?!

If I were to build the bucking transformer what else would be nice to have apart from the transformer?
 
The parts for a bucking tranny are inexpensive, so it won't break the bank to give it a go. You will need a DVM to measure AC voltage though. Getting the phase wrong simply means you'll be stepping up the output voltage instead of down. I did that with my first go, so easy mistake to make.

Just take care with lethal voltages.

What else would be nice is a case for the transformer.
 
Don't know if this helps but a couple of years back I rebuilt an ILP modular amp that I originally put together when I lived in Holland (looked nothing like yours except the trafo to PCB connections).

I was a bit concerned that the toroidal transformer might be specified to 220v and after a bit of searching discovered that ILP were still active and sold via eBay so contacted them via their business details listed there:
https://www.ebay.co.uk/usr/ilpdirectltd

Ian Potts
ilp direct ltd
[email protected]

I cited the model number printed on the trafo (in my case 42027) and Ian replied a while after confirming this model was suitable for 240v operation.

You could try the same path ....

Got in touch with Ian but sadly he could not help out because no transformer records are available.
 
This site contains affiliate links for which pink fish media may be compensated.
Got in touch with Ian but sadly he could not help out because no transformer records are available.

You could contact the original Onix 601 designer and circuit brains - Tony Brady now at Exposure.

Tony is very helpful and approachable. I will PM details to you shortly.
 
The tucked away wires from the transformer could be to change primary voltage:

fBve5ZR.jpg

Nice idea, but there is a serious safety 'gotcha' with this approach.

by connecting a secondary winding on the primary side,you have weakened the transformers isolation capacity from the mains. There is an insulation layer in a toroid between primary side and secondary-side windings (usually specced for 3 or4KV, depending on applicable standard) iirc.

If one the secondaries is then used primary side, that essential isolation barrier is bypassed and your isolation from the mains is ONLY the condition of secondary wire insulation enamel. Potentially lethal.

(NB this is true of a bucking- arrangement too, but it matters less -you already treat the whole buck transformer as live-to-mains - which is then protected-against by the retained, existing mains transformer which it feeds)
 
Nice idea, but there is a serious safety 'gotcha' with this approach.

by connecting a secondary winding on the primary side,you have weakened the transformers isolation capacity from the mains. There is an insulation layer in a toroid between primary side and secondary-side windings (usually specced for 3 or4KV, depending on applicable standard) iirc.

If one the secondaries is then used primary side, that essential isolation barrier is bypassed and your isolation from the mains is ONLY the condition of secondary wire insulation enamel. Potentially lethal.

(NB this is true of a bucking- arrangement too, but it matters less -you already treat the whole buck transformer as live-to-mains - which is then protected-against by the retained, existing mains transformer which it feeds)
Some transformers have multiple primary windings as shown in the drawing. If this is the case here, connecting them in series is safe and the intended way to use it with 240 V mains. Repurposing a secondary winding is definitely not recommended for the reasons you state.
 
My picture shows the 18V as a winding on the primary side: this kind of transformer has 3 windings on the primary side (and the picture shows only one winding on the secondary side): for 110V you would put the two 110V windings in parallel, for 220V in series, for 240V you would have all 3 in series. So for 110V and 220V you would ignore the 18V coil: it's wires need to be tucked away in this case. Of course this is not meant to be done with a 18V winding on the secondary side!
 


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